2002 Toyota Tacoma 4 cyl engine knocking

I just purchased a new 2002 Toyota Tacoma Xtra cab, 4 cyl, 5 speed. It would be a nice truck except for a minor problem. The Engine knocks.

the day I drove it off the lot I thought it was an exhaust noise but am now convinced it is a main bearing knock caused probably by a bad crank. I took it to the service dept and they could not tell me what the noise was but said it was typical of this years engine. Now that I have driven it for 2600 miles I am sure it is a bad crank. I hear that a few others had this same problem. Toyota has agreed to replace the short block but I said no, I want a refund. I spent good US dollars and I expect a good product, not one that has been overhauled.

Anyone elso know of others with this problem?

I haven't had that problem, but if it is a common problem I guess I should be worried. I had a leaky place in my firewall that soaked my floorboard in the passenger's side, and the dealer told me that it was a common problem also. Where are the recalls?!! All of these damned common problems!

I've got it too. 2002 2.7L 4x4 etra cab 5 speed. dealer does not know the problem. They gave me the same line about short block replacement. Supposed to let me know on 11/19/02. 2 other trucks were at the dealer for the same problem.

My truck started making the noise at 2000 miles

Good luck getting a refund. I am in South Carolina and we participate in the lemon law. They get 3 tries to fix. If not, I will have legal recourse. I have the 100k warrantee also. So, they have awhile to deal with me. If everyone that has this problem would raise hell about it, Toyota would do the right thing.

Keep us updated on your issue. As will I.

Later

Mine is a 2003 2.7L 4x4 and it makes a deep knocking or thudding noise prevalent between 1800 and 2000 rpm under light to moderate loads. The noise is more evident when the engine is cold. I also notice a clutch noise like judder when the clutch is engaging and is slipped a little on upshifting but there is no pedal pulsation, not like any clutch chatter I have ever experienced. I am wondering if the clutch and engine noise issues are related perhaps as you mention something to do with the crankshaft end thrust. The engine has 1100 miles on it and the engine noise seems to be louder that when brand new. I am wondering if I am experiencing the same sound you others seem to hear, deep knock, but not a true main bearing rumble, being the key here, I would also be most interested in knowing if your dealers have diagnosed the problem. My dealer says: " they all do that , wait a while." SO here I am , waiting for the moment.

It is also my understanding that documentation is extremely important in Lemon Law cases and that any evidence that the defect is widely known is also helpful. Would like to keep in touch.

Cam

Well, I finally went in to the dealer with my issue. The tech can't hear the knock. Funny, I kind of suspected I would get that answer. They say maybe exhaust resonance or injector pulses. I didn't know those could knock/thud. True, it isn't real loud and it doesn't sound like a diesel but my buddies can hear it, and drives me nuts, so now I am off to another dealer. I strongly suspect is this is a crank related problem and sure would appreciate hearing what other dealers have said about the cause if any of you have had the benefit.

Well, you guys can add me to the list. Same knocking sound between 1800 and 2000 under light load. Engine doesn't feel as if it's missing. I can hear the noise very faintly if the truck's parked in neutral, clutch out, and revs bround up to around 1000. What bugs me is that I spent hours reading all the reviews of Tacoma owners who'd owned crummy small American trucks and were much more satisfied with their new Tacomas. So I go out and buy a year-old '02 with 8K on it and I get a rod noise along with the deal. Great. :mad: Well at least I got an extra warranty that covers me to 100K. I'm not sure if I'll go back to the dealer with the problem -- I may just drive it as is and let it be a rolling advertisement against this motor. We'll see how bad it gets over time....

OS

I have now been to a second dealer and they acknowledge the noise and agree it is telegraphing through the clutch. They tell me it would show up on the knock sensers but it is not a problem. Do they know what it is? No! Or at least they wont say so. They wrote it up as "no correctable condition found" with no other comment. When pressed about this comment they said since it is not a problem, this is how we generalize.

I have lost all faith in Toyota. This second dealer even suggested they would charge for a dianostic if they did more other than a test drive with a tech. I guess that in my area you have to go the toyota dealerships with your attorney in tow. Unbelieveable!

I am also experiencing the knocking noise. At first I thought it was the brand of gas I was using and then maybe the octane but that didn't work. I then contacted the dealer and they scoped the motor, checked pulleys for chatter, checked the exhaust manifold for cracks and just about anything they could check and then sent me home. They said I would just have to drive it until it worsens or breaks. Not a good feeling at all and after owning alot of fine Toyotas in the past this one worries me. I check in here while surfing to find that many others are experiencing the same problem. I have contacted the dealer and when they reopen after the holiday I expect to get some awnswers. I can't put up with this, like previously stated it just drives you nuts. Obviously Toyota has problem. I have an automatic so that leaves out the clutch theory for me. Its time to get to the bottom of this.

jv::

In 01, I bought a 2.7 liter Tacoma 4x4 reg cab and had the same problem. It would make a knocking sound only when I'd start it up in the morning on a cold day. After running for about 10 seconds, it would go away.

Now my truck has almost 39,000 miles on it, and it hasn't made the sound in about a year and a half so I'm not too worried about it. I wonder if it happened only when I was breaking in the engine? Any thoughts on this?

Your noise sounds like it may have been an oil circulation issue when cold. Higher ambient temps, different oil or possible breakin could change when or if you hear knocks on start up. I have experienced the cold start up rattle and it is not the sound I am concerned with, nor do I really think this is the same noise others are hearing. Still waiting for someone to post a difinitive comment from toyota. No doubt we all wish it would just go away.

originally, I thought it was a post '01 problem, but if Jeff is having the same problem with his '99, you have me stumped. I'll ask my Toyota mechanic this weekend. He's always been a reliable source for these things.

I have contacted Toyota and they sent me through corporate head quarters. They told me who to contact at my dealer and I did just that. They tell me the problem has been documented. All that they can do is take my truck back for about a week and see what they can find. Toyota told me that there hasn't been any other complaints so I suggest you guys get on their website and give them a call or an e-mail and let them know whats happening with yours also. There is definitely a problem with something.

I might add that mine makes the noise while cold and hot. Its very annoying and I still think it runs different since the noise showed up.

I will have to take the truck back sometime soon and let them have it I guess and see what they come up with. That will be a second and then I may have to try another dealer for my third try and then back to corporate. What a mess!

I have just been to the dealer again, this time to replace a defective ball joint seal. I asked them again to check out the "noise" The tech agreed it was weird; the first thing that came to his mind was thrust washers on the crank. He said he would investigate and enlist the aid of other techs. When I got he truck back I was informed they had driven a brand new Tacoma with only 9 miles on it and it made the sound too. From this it was concluded the sound was normal, an artifact of this particular engine. Early on in this adventure, I contacted Toyota and documented my concerns about the sound, so they have heard about it. Thing is, the Toyota help line is just a receptionist and the record apparently goes nowhere. It might possibley help if the problem becomes catastrophic after your drive train warranty is up. I really believe this noise has everyone stumped and they hesitate to really spend any time trying to figure out what it is.

Thanks for the update Cam P. I have been watching to see if anyone has come up with anything. I still haven't took mine back to the dealer but I'm really beginning to wonder if its worth it. I hate the noise but if nothing is really wrong why bother. It's an ify matter. Like I stated previously I contacted toyota and my problem has been documented but thats all. I think too they would take care of us if something did come out of this after the warranty but ya never know.

Jeff

Since Jeff has mentioned his runs different since the noise started I wonder if this noise is not possibly igntion related. I have been carefully listening to mine and I am beginning to suspect that the noise might be transmitted to the bell housing ( therefore feeling like it is trans and crank related) through the bracket that holds the exhaust head pipe to housing. I took mine to a Japanese mechanic and had him listen to the noise and he thought maybe there was unburnt fuel igniting in the ehaust system, but not on every firing pulse. Also I notice that
my sparkplugs don't show even color all the way across and two of my coils are different in resistance by just over 10%. I wonder if anyone has had Toyota hook up their computer to look at ignition. This kinda seems like grasping at straws but it is the furthest I have gotten trying to identify the noise.

In spite of that fact that the dealer said a new truck made a similar noise, I don't believe that justifies the thing as normal because it is to say that any problem is unique to a particular machine. Recalls disprove this in a big way. One dealer also told me the knock sensors should hear this sound. The Japanese mechanic I spoke to said it is likely that the dealers don't want to take the time to chase this down because it is a difficult diagnosis and Toyota won't reimburse for much of their time. So you get a truck with noise that might cause premature wear but probably will fall outside of warranty. I guess I just don't have enough trust in the dealers after they say " oh yes, disturbing sound" then speculate an dfinally rationalize it away. After all the techs I have had listen to it, there is about 110 years of combined experience and no adifinitive answer as to what it is.

With my 2000 Tacoma STD Cab, 2.4 4Cyl have had a knocking problem since I first purchased the vehicle. USUALLY it occurs only when the truck is COLD and for the first few minutes after starting. However, recently I have noticed that it also occurs (on occasion) even when it is hot out. Have brought the truck in to the dealer, they simply say that it sounds better than most.

The sound is kinda like, to me, that the engine is not being timed right by the computer or it is not getting the proper lubricant to the Top-end.

It really feels to me that the dealers know the problem, but they feel that it is in their interest to keep tight lipped on this one.

By the way, I had a 1986 Toy Trk 2x4, it had way more torque and much better gas mileage.

Cheers!

p.s., Any advise on problem or possible RECALLS?

Maybe you should use a higher octane.

I think most of us have tried higher octane and it hasn't helped with this annoying problem.

Jeff :frown:

Chet,

Couldn't agree with you more on the 2x4. Them things really run compared to the 2.7 these days. I miss the 22r and 22re motors. I thought when I purchased my newer toyota with the 2.7 that I would have all kinds of power and man was I wrong. This thing is a dog compared to the 4x4 with the 22R in it too.

Sometimes things are better left alone. If it ain't broke, don't fix it!

Jeff

I've notice people having a rattling noise with the 2002 Tacoma.
Well about a week ago my 2002 4cl 4x4 Tacoma started to rattle.
About 20 miles later, the car seized and the engine shifted and was undriveable. Still under warranty, I took it to the dealer and due to a
"defective bolt" Toyota is replacing the engine, or so they say.
Now I'm told that they are reusing the original parts and don't plan on
extending the warranty. I'm finding out more and more people are having problems and Toyota is well aware of the defective parts.

ANYONE ELSE EXPERIENCING THIS PROBLEM ???? Do I have any recourse??

It is unclear to me what happened to your Tacoma. Did the engine seize then break a motor mount bolt? If you describe the sound as a rattle as opposed to a hollow thudding, I supect you are talking about a different noise than I experienced or perhaps the rattle develops after the thudding sound. Did your sound come all at once or did it develop over time? It certainly seems the dealer is not giving you a very clear explanation of what the problem is. Perhaps Toyota doesn't want it to get around. You are lucky you have a clear problem and are still under warranty unlike other in this post who can't get any satisfaction. Depending on what failed, I would possibly be concerned about:If it is a piston seizure, your cylinder block will have to be bored to accomodate oversize pistons. The dealer would probably have to send this work out to a machine shop. I am surprised they would want to take the time to tear the engine down themselves as opposed to just getitng a new engine from Toyota. The downside is that your engine will be overbored, but if done correctly not really a big deal. The upside is that the machine shop might do a better job of fitting the pistons to the new bores than the factory. Unfortunately, this would be hard to monitor unless you know the reputation of the machine shop used or can stand over them and know the procedure and specifications for fitting. Get more clear information on what the problem is and what they are doing to resolve it. If you don't like it demand to see the regional rep. Call your state attorney general and see what laws may affect this. Private law suits are a pain as you might imagine.

I own a 2001 Tacoma 4x4 extended cab with the 2.7Liter 4 cylinder, and as of what seems recent (perhaps the colder weather?), the rapping that is coming from my motor was looked at by the best mechanic I know. It is intermittent, but when it occurs, it will carry on as much as 10 minutes max before it diminishes into the background, although I am fairly certain it is still there. The mechanic put a pressure gauge in place of the idiot light and oil pressure at idle was @ 23lbs. It exceeded 80 lbs. when revved. We then removed the spark plug, inspected the combustion chamber, and all looked fine in there. Using a headset, and amplified microphone, was able to localize the noise to the front of the motor, in the region of #1 cylinder, in the head area, and not in the block, however I make no generalization as to this knocking problem be isolated to only one type of failure. This noise is mechanical, and seems to be the result of metal to metal contact, but its location does necessitate disasseembling the top end in my case so I will first approach the dealership to document the complaint with them. I am completely disheartened by the experiences of this forum, and expect no satisfaction with the dealership in truly solving this issue. But one thing is certain, and that is that it "is" a problem now, and I will fix it one way, or the other. I will keep this forum posted on my progress as I think we all agree as to why we own a Toyota, and this issue has me feeling shorted on the key reason, "reliability, and long lasting".
Symptoms:
* Happen when cold or hot
*Rpm consistent with others-1000-2000
*replace oil filter-no change(suspect bad check valve function)
* no skipping or rough running at idle or in motion
* 93 octane since new
* spark plugs are burning even(all) and good temperature
* no cooling issues ever

Yes, please let us know. I haven't done a thing with mine. I'm depending on Toyota to treat me fair since they told me its been "documented." Whether or not they will is one thing. The noise I heard seems to be getting slightly worse so in time I'm sure something is going to go.

I have had the same problem with my 2.7 Taco. I know this may sound crazy but i ran 2 bottles of techron in the fuel tank and havent heard the noise since, that was about 2 or 3 months ago. I run techron additive every oil change and i find it vital in these motors. No, i am not a sales person for Chevron Techron but this is 1 additive that really does work. I also suggest you avoid excessive idling in these motors, they build up carbon to easily.

mudpaws02,

Where do you get Techron? Did your engine make a dieseling sound like cheap gas in it?

Jeff Vought

You can get techron in most auto part stores, like pep boys. Yes, my engine made like a deiseling sound for the first min or so upon morning start-up or if the engine was off for like 4 hours or so. It was very loud and could not be missed. The additive is called chevron techron. I am not one for additives but this stuff really does work.

My 02 Tacoma 2.4 had an engine noise and at 24K the dealer had to replace the engine. First Diag.-Scorched rings. Sec. Diag.-Valve problem.
Final diag. Cyl. out of round. The last one makes more sense to me. Anyway, they replaced it.

Just so you will all know ....
Make SURE to keep very good oil change records! That will be their first tool against you in making it look like it's your fault. They tried it with me. I knocked that out quick.

Hi! After reading all of your responses and having had a couple of laughs I need to tell yas that i just got through speaking to a master machanic about the Knocking sound in our 1998 Toyota Camry, 2.2 liter, 4 cylinder car. He stated that there have been problems with this year car, Carbon can build up inside the chambers and cause the Knocking sound especially if the piston starts hitting it. The solution to the problem is having the engine scoped and look for the carbon, IF ANY, and then what they do is somtimes rev the engine until the knock stops, or to place solvent , such as gum out, to break up the carbon. Another thing that he said the knocking noise could be due from the engine balancer weight, which lies under the oil pan when its removed. Said it could be off key and causing the knocking sound. The last thing that he stated and is the most costly for this Knocking noise, was that you threw a bearing and it needs replacing. The bearing problem is usually caused by somthing else going wrong with the engine, such as lack of oil, dirt in the oil, placed together wrong, tourched wrong, etc; I am pleased to be able to leave you people with this tid-bit of info. We still need to find a solution to our problem with the Knocking, but have a certain track to follow right now.

Out of curiosity, how often do you all change your oil in your Tacoma's? I've seen the book say 5000 miles, but I prefer to stick to 3000, especially for the change in seasons.

I have a 2002 2.7 that I bought used last year with about 13,000 miles. One year and 10,000 miles later no problems. I do always use Chevron gas and I've used the Techron Fuel Injection Cleaner that was referred to earlier at each oil change. Again not a Chevron saleman, just tried the different types of gas and have had no problems with the Chevron. Shop around a bit if you buy the Techron cleaner though. Out west I found the price range from $3 to $10 for the same item. I think Schucks was the cheapest.

Hey everyone...
I feel for you all. nothing worse than weired noises from your truck and the dealer don't have a straight answer. I have a 95 2.7 and I've never heard knocking from my engine. The only thing it drops dead at idle in commute traffic once a year. Then it start right up. change oil religiously and run gas treatment twice a year. just switched to amsoil. Just had the valves adjusted at 145,000 due to a routine compresion check. a starter and a battery. best reliable truck I ever had.

Why I am asking about oil filters is when I bought my 96 taco used ..36k on it It had a penzoil oil filter on it and My Toyota Mechanic told me to get that off there asap . He said only use Toyota oil filters , Because they have a built in shut off valve in them that keeps oil in the top of the engine , So you dont have dry start-ups .... He had a stock one he took apart for me and showed me .. So I know thats true .. So if you are getting knocking at start-ups that could be your problem .. My Taco also has a 2.7 in it and I dont have a knock in it . But I do have a crack in my exhaust Manifold .. and need one ..Hint Hint The only problem I have had with my taco or 2.7 engine is Keeping water out of the engine area .. I have replaced one horn already from water ( because it is in a bad spot ) Now I have to replace the exhaust manifold because of water ..

Just an update, never had it checked and it still sounds and runs the same. Gonna keep on driving it. :)

i would take it to the dealer if its under warranty.

Purchased 99 used reg. cab tacoma 4x4 w/38k miles. Started making diesel gurggling sound about 60k miles, around 2k rpm, under light load. Add me to the list. Will approach dealer, any suggestions?

I have just brought my 2002 tacoma 4x4 with 4 cylinder engine in to the dealer for the second time for an inceasingly louder knocking sound, especially when the truck is started cold, but it is also audible at cruising speeds. The first time I brought it in, they just told me that it is a loud engine which is characteristic to these toyotas. The second time I brought it in, I left it overnight, and they called me in the morning and told me they had ordered a new engine which is covered by the original warranty. They told me that it was caused by the WRIST PINS. I now have 43,000 miles on the truck, this problem started around 20,000. So by next week I will have a new engine in the truck. I also experienced the problem with the leaking passenger side when it rained, which they brought to a body shop and replaced the carpet.
Even though this has been a pain, at least toyota has always supplied me with free, brand new rental cars whenever I had to leave the car overnight for them to work on it. It has suprised me that they have actually honored their warranty without me even having to ask.

Glad to hear about the new engine. I have a 2003 that also leaks when it rains. BOTH side of the truck leak into the cab.

Mike

I posted a message about a week ago concerning a knock from my engine compartment entitled "Harmonic Balancer Heads up". This knock was fairly loud and consistent and increased when revved. It seemed to get worse when the fan was on or the AC. It turned out to be the crankshaft pulley was loose and wobbling around on the end of the crankshaft. Everyone who is having a knocking problem, check your crankshaft pulley (the main pulley behind the cooling fan, usually has 1 or 2 accesory pulleys with it). The crankshaft pulley is also known as the harmonic balancer because it is drilled out to be balanced in sync with the timing of the engine. If this is loose, the center bolt has worked its way out a little and this can cause a very distinct, loud knocking sound that will eventually damage the inner workings of the engine because the timing is being thrown off. I have a 2000 4cyl with 68000 miles on it. The knocking started at ~65000 and then I fixed it with a new pulley and new center bolt. Good luck everybody.

yeah, i had the same problem when i first got me taco even my friends who brought his taco earlier this year. at first, i was freakin out too but later the knockin went away. i've asked alot of people about this problem some say it's the crank shaft..some say that's wat happen when you break in the car...

I have a 1996 Tacoma 4X4 with the 2.7. My engine knocked like that for about 160,000 miles but never caused any problem. I now have 257,000 miles, the knock is gone, the engine runs GREAT and doesn't use oil between oil changes at 3,000 mile intervals. I am rough on my Taco because I off-road it on hills, cliffs and rocks, but I have not had any problems with the drivetrain. Replaced the original clutch at 238,000 miles.

My exhaust manifold did crack but I replaced it with an LC Engineering header for about the same price as the manifold. I use the Toyota oil filters because of the anti-drainback valve they suposedly have to keep more oil up in the engine when it starts up initially.

I have had two 1998 Taco two wheel drives. Both with a 2RZ/2.4 L
Both trucks ended up developing a rough idle at times with a noticable tapping noise. when the engine is running good it is virtually silent. ?I? tend to drive it very hard...

but today the check engine light came on for a while. I parked it and 5 hours later drove it 100 miles and it did not come on again.. very wierd.

Could someone explain to me what this "knocking" would sound like? How loud? How fast? From where? I've searched different websites, and yet to come across one that I could understand!

Thanks. :P

check the crankshaft pulley (harmonic balancer). I had the same problem on my 2000 4 cyl and it turned out to be a loose pulley that was throwing the crankshaft off balance. Good luck.

Is everyone with knocking engines using 5W-30 motor oil? What oil filters are you using? I'm just curioous as my 2004 Tacoma has only 7600 miles and sounds fine at present.

Regarding oil filters, it seem all dealers will tell you that their filter has an anti drain-back valve and others do not. That is not true, I have never seen a replacement filter without an anti-drainback valve. Some filters are poor quality, Fram is one, and I have experienced some problems with them on other vehicles. I noticed the original Toyota filter for my truck was made in Japan, the genuine Toyota replacements I bought were made in the USA and have a different part number. There are only about four manufacturers of filters in the USA and I assume one of them makes the Toyota filters to Toyota Specifications. On the Tacoma 2.4 engine the filter hangs down so it doesn't matter if the filter has no anti-drainback valve the filter will not leak dry, oil does not drain up hill.
Clifton

Well I have a 2001 Tacoma, 2.7L, 4 Cyl, xtra cab, 5 speed and guess what..... The engine is knocking!! I currently have 63K on it (with 100K)warranty). I believe that the knocking started around 40K in the early Spring and at the time it sounded like a light rattling (as if there was a loose bolt). It would happen during a cold morning start and then go away within 30-60 seconds. The noise went away during the summer months and then returned late fall. It no longer sounds like a loose bolt, it definately sounds like metal knocking against metal. I have heard the knocking, idle as well as 1800-2200 RPM. It does not however, consistently make the noise. Some cold mornings it won't make the noise and other mornings it will.

Hopefully Toyota will be able to duplicate the problem and tell me what they think it is.

I'll keep ya posted.

Tred

It is very clear that the posters in this forum are hearing a variety of sounds that they refer to as a "knock". For example : It appears that speciald's knock is likely coming from the top end and by his description of it occurring when cold disappearing when hot, it is likely piston slap and his anomaly is likely oil dependant. Toyota went to short skirt pistons around 1995 and are prone to slap more so than the long skirt pistons previously used. Fitting tolorance must be more closely observed on assembly. Others have traced their noise to harmonic balancer, etc. Mine was a thudding knock coming from about the middle of the engine, rather low. The thudding aspect is the most mysterioius part as it makes it very difficult to trace being that it telegraphs all over the place. Metal on metal usually has a teletale pitch. Valves click or tap, wrist pins tap, pistons make hollow tap/slap, rod bearings knock, main bearings rumble (a rotatational low knock as it were). These are generic descriptions, trouble is until you can identify with them, almost everything is knock of a sort.

My sound doesn't fit any of those listed above. I began to think there maybe was fuel igniting in the exhaust manifold with harmonics sending it around all over the place. Toyota folks wouldn't or couldn't speculate. I finally got tired of trying to figure it out and sold the thing. What ticked me was Toyota's dealer's lack of willingness to look into it further than going on a test drive and acknowleding that there was a "noise"

2003 Tacoma 4cyl Reg Cab Automatic 17,000mi.
Hi
New to the site. I just wanted to document my info on this forum
Intermittent knocking in/around engine.
Also have the "clunk" - when switching into park, reverse
etc. Like the knocking, the "clunk" comes and goes under unknown circumstances.

Oh yeah, I paid cash and they didn't even give me floormats. >{
Going to take to dealer soon. Will update.

i have a 2000 tacoma 2.7L with just over 100k now and ive got the same noise. so far it only happens during the winter, usually only at first start-up in the morning. it is a deep sounding, low hollow knock and doesn't really last too long (although longer this past winter than the winter before) but it drives me crazy and it really does sound bad. two dealerships have diagnosed the sound as "normal", one of the two said it is piston slap. seeing as its summer now i dont have to deal with it, but man would it great to not have to hear it when the weather starts getting cold again. please post again if you find a solution to this problem. take care all.

Try using a block heater in the winter.

thanks for the suggestion, i had actually been considering that. but, i must have jinxed myself with that last post because this morning, the truck was knocking despite warmer weather. disheartening to say the least...not sure if its the same knock or different one now. this morning it almost sounded lighter and lower down on passenger side. it only ever happens if i actually drive off before the truck warms up, and doesnt really last long enough to do a decent job of trying to locate it.

G'day, Over here in australia we have the 2.7 engine in our hilux range
of trucks, mine is a dual cab 2wd and my friend at work has a single cab,
both are 1998 models, mine is auto and his is a manual, mine has done 160000 km his 56000 km. these hilux's are built in japan,and they are the top selling trucks in australia. we both have the same knocking noise.
the low milage truck knocks on cold start almost every morning and if left
for 4 hour+,the high milage truck knocks some mornings only, the noise is the same in both. it lasts around 10 seconds and is loud enough to hear with windows up and radio on.it is a real metal to metal knock. i am a mechanic and it has me stumped, one theroy i have is that the main timing chain tensioner creeps back when the engine has stoped (it has a ratchet pawl to prevent this)and on startup the tensioner arm is slapping back on the tensioner,after a few seconds the oil pressure pushes the tensioner back out and the noise goes away. the toyota service manual says to check the operation of the ratchet pawl at overhaul. if i pull my tensioner out i will post again to let you know.seems to me toyota's are knocking all over the world.

My 2003 Tacoma 2.7 made a loud knocking sound on a cold start-up.My dealer said carbon on pistons,decarboned the head and the noise went away.

I have a 2001 2.7 Tacoma 4x4 and it also started knocking just a few days ago. I have 98K miles on it. Mine knocks after it warms up, about 15 min. and stays kncocking.

I am taking it to my mechanic this morning hopefuly it is just a valve adjustment issue. Does anyone know how often you are suppose to get the valves adjusted. I have done virtually nothing to the truck in 5 years other than oil, brakes and tires.

Some of these posts are a bit disturbing and I do not know how long the Powertrain warrenty is on my truck, I think it was at 100k but I am fast approaching this mark and if that is the issue than I want to start the issue with Toyota today before I go over that mark

My mechanic looked at it yesterday and determined it was not the valves and that it was the oil pickup screen that was clogged and causing the knock. The bad news is he found what appears to be pieces of my timming chain tentioner. Once he puts the oil pan back on and the front trans he is going to pull the timming chain cover and check that out. I will keep posting until it's fix

"My mechanic looked at it yesterday and determined it was not the valves and that it was the oil pickup screen that was clogged and causing the knock. The bad news is he found what appears to be pieces of my timming chain tentioner."

I think your mechanic should at least look at the rod bearings before installing the oil pan, I'm very surprised he/she didn't suggest that. If the clogged oil pickup is really the problem and the engine was run with the knock there is some bearing and perhaps some crankshaft damage. To me this would be a bigger problem than the assumed timing chain tensioner parts. I Wonder how he determined the screen was clogged enough to cause a knock? A defective timing chain tensioner could also cause an engine knock. Sounds like your mechanic isn't sure what is causing the knock.

If he blames it on the oil screen clogging, they are probably going to say your oil hasn't been changed as the maintenance schedule prescribes. Do a Google search on "Toyota engine sludge" and see what comes up.

I'm not saying the tensioner parts should be ignored, that should be corrected, but not before making sure the main and rod bearings and their associated crankshaft journals aren't damaged from lack of oil due to the clogged oil pickup screen.

Clifton

This link has lots of Toyota engine sludge information.
http://www.google.com/search?hl=en&q=Toyota+Engine+Sludge&btnG=Google+Search

Clifton

"My mechanic looked at it yesterday and determined it was not the valves and that it was the oil pickup screen that was clogged and causing the knock. The bad news is he found what appears to be pieces of my timming chain tentioner."

I think your mechanic should at least look at the rod bearings before installing the oil pan, I'm very surprised he/she didn't suggest that. If the clogged oil pickup is really the problem and the engine was run with the knock there is some bearing and perhaps some crankshaft damage. To me this would be a bigger problem than the assumed timing chain tensioner parts. I Wonder how he determined the screen was clogged enough to cause a knock? A defective timing chain tensioner could also cause an engine knock. Sounds like your mechanic isn't sure what is causing the knock.

If he blames it on the oil screen clogging, they are probably going to say your oil hasn't been changed as the maintenance schedule prescribes. Do a Google search on "Toyota engine sludge" and see what comes up.

I'm not saying the tensioner parts should be ignored, that should be corrected, but not before making sure the main and rod bearings and their associated crankshaft journals aren't damaged from lack of oil due to the clogged oil pickup screen.

Clifton

He orginal, before taking anything apart, thought my valves needed adjusted but after 2 hours of research he was leaning more towards the Oil pickup screen. He said the screen was clogged with small pieces of metal from what ever he found in the oil tank. This is not a dealer, it's a mechanic I have used for 15 years and I trust his work and know he will not overlook anything nor will he rip me off. He only charged me $350.00 to pull the oil pan and replace the pickup screen, By the book this is a 6 hour job. The dealer wanted $650 just to pull the oil pan and inspect everthing, no replacement parts just looking. I trust his judgment and I am sure he will look at everthing before it puts it back together. He builds race engines for cars, boats and motorcycles and has been doing this kind of work for 35 years

It does help that you have prior experience with the mechanic and trust him. Please let us know what really corrects the problem.

Clifton

It does help that you have prior experience with the mechanic and trust him. Please let us know what really corrects the problem.

Clifton

It looks like I need a new engine. My mechanic found that the metal was from one of the harmonic balancers. the passangers side will sway side to side about 3/4". This is rediculous to have to replace the engine after only 98k miles on it. $5k later and a new engine hopefully I will be on the road by next week.

That is depressing, I was hoping it would be something simple. Thanks for keeping us posted.

Clifton

I too have a similar problem. I purchased an 01' tacoma on the used lot with 58,000mi, about two years ago. I hardly ever drive it (I commute on a motorcycle) I now have just over 64k miles on it. I am an ASE certified and Rolls Royce master technician. I have taken good care of the truck. My knocking is getting worst every time I drive it. It closely resembles a diesel. I have determined that it is piston slap. It occurs on a warm engine, at idle. It is fine all other times other than the driveline vibration(different story) This is most likely the cold start noise most of you are having. The piston takes time to swell into the cylinder. Mine on the other hand has prematurely worn out. I have an appointment scheduled with toyota on Wed, I have a bad feeling my "extended warranty" will fight me until I fix the problem myself. I was able to get a new transmission last year when a main bearing crapped out. I am not happy, my 91' 22RE was far superior to this truck. I had 193,000 on it when it was sold. I'll keep you all posted. Justin