My 1993 Trooper LS has been wonderful. I've needed to replace the waterpump which squeels at me for the first few minutes, but now I've suddenly developed another more serious problem. I've heard the lifters tick for the first few seconds after startup for awhile now, but just the other day out of the blue I developed a very loud ticking or almost even a rattling (but I wouldn't describe it as a knock) noise that seems to be coming from somewhere under the right valve cover or under the intake. The speed of the tick/ rattle corresponds to engine RPM, but seems to be at maybe half the tempo that you'd expect a lifter tick to be. It is so bad that you can even feel it by placing your hand on the engine. If you rev the engine, the noise speeds up accordingly then disappears consistently at 2200RPM. Once RPM falls below 2200, the noise returns immediately.
I was 200 miles from nowhere in Alaska when it developed so I drove it back to Anchorage and maybe another 20 miles since and it is still going strong as ever, but I'm afraid to do anymore damage. The only thing I've done so far to check the problem is: 1) change the oil and filter -no change 2) loosen waterpump/ fan/ alt. belt so waterpump would not spin to make sure that was not problem -no change and 3) pull plastic cover in front of right side timing belt/ pulley -With the engine running I applied slight downward pressure to the top of the pulley/ belt with the side of a screwdriver. When I did this the noise quieted substantially but did not go away completely.
Has anyone experienced this problem? I don't know if it makes a difference, but that night was the coldest weather the Trooper has ever been in. It was between -10 and 0 F plus 20 - 40 mph winds plus driving down the road. Any information or advice would be greatly appreciated.

thanks,
Matt

Sounds like your hydraulic timing belt tensioner gave up the ghost. Very common occurance on these engine @ higher mileage. Knocks at idle & stops when you increase engine RPM's. May be a good time to changeout your timing belt, tensioner & water pump, since they're all burried under the t-belt covers.
G/luck
Joel

Thanks a million for the helpful info. I just picked up a Chiltons manual (all I could find) and it mentions a timing belt tensioner pulley and a pusher. There is a "tensioner bearing" available aftermarket (which has to be shipped from the lower 48), but nothing else. I'm wondering if anyone knows if this is the likely culprit or not??? How big of a pain is this job? I'm going to be doing it outside as I have no garage to work in. brrrrr!

Ak'...I feel your pain brother. I have a 96 Acura SLX with 125k miles on it and having the same issue. I will let you know what I find out and please let me know if you find anything out new too. My problem was intermitten at first but has been a little more persistant over the past couple of weeks.

Hello.
I had a similar situation last week while out in a remote part of west australia. Temperature was over 120 degree F. All four wheel drive country for about 200 kms, and bumpy.
Over 2000 rpm the noise stopped. A mechanic in the first petrol station I arrived at said " hydraulic tensioner". The trooper in australia is called a holden jackaroo.
Unfortunately he did not have one and as they would take 3 or 4 days to be delivered I just drove home. So I had just to take it easy for 800 kms to home.
A local mechanic there has stripped down the front and the hydraulic tensioner was just hanging on. The belt was in bad shape as well.
I am having the hydraulic tensioner replaced right now (4 january 2005), also timing belt. The tensioner was shot and was allowing timing belt to touch side of plastic timing belt cover. At higher revs the belt was in higher tension due to revs so would not allow belt to touch side of cover (and so noise would stop).
Hydraulic lifter noise. I changed oil to Magnatec engine oil and the noise went away after a few kms. Still a little tick now and then but its not too irritating.
Total cost for replacement of timing belt and tensioner is 750 australian dollars. Isuzu parts are expensive here, 300 australian for the tensioner alone. if I had gone to a holden dealer it would have been double.
Hope this helps

And I have just picked up the repaired vehicle this pm (4 january) and it is as quiet as a mouse. (well a clockwork one anyway). It was the hydraulic tensioner and the timing belt. Final cost 680 australian dollars.
The noise must have been increasing over the months and it is suddenly very quiet driving along.
hope this helps.
ps. vehicle has done 194,000 kms. 1992 V6 3.2 liter with automatic gearbox.

Thank you pharress, I am going to start ordering the parts here in FL. Looks like the parts here are about $180 US. I have about 201125 kms on mine and the sound it getting louder.

Yes, definately the the belt tensioner, very common on these trucks. Isuzu actually revised the design for it, so I'd go with a new Isuzu part. May as well replace the waterpump while you're in there.

As far as the lifter ticking, try some "Seafoam" in the oil for a while, flush, the go with a low cold-weight synthetic (indicated by the first number) like 0w-30 (Mobil-1 in the tsb), 5w-30, 5w-40, etc. Avoid 20w-50 like the plague! I've had good luck with 5w-30 Mobil 1 and Rotella T Synthetic 5w-40.

I would agree with gotdurt, Seafoam when you are changing the oil works when lifter noise. I tried some of the "lifter quiet" products and I think the lifters were quiet for the amount of time I backed out of my driveway.

I am not advertising or promoting products, but I did use a product called EngineEZ, it seems to be keeping the lifters pretty quiet or at least not embarassingly loud. If you are interested please private message me and I will send you the link to where I got it.

Hi everybody! Isuzu parts here in Denver claims that the tensioner is no longer available from Isuzu. Can anyone substantiate this? I am getting ready to do the job on my 92 trooper s, and the only place in town that has it is Carquest, and the guy had to run to the wholesaler to get it. Here goes another fun t-belt job! Anyway, I will post when I am through with the job with the procedure and any tips from you guys would be killer! I am replacing the t-belt, tensor, water pump, and front crankshaft seal. I don't want to open this thing up again for 60k, so did I forget anything? Thanks for this forum, it is a real lifesaver!
Rob

Well, I did the job on Saturday, and into Sunday a little just to get everything cleaned up. What a job that was. I changed the t-belt, tensioner, and the water pump. The timing belt tensioner was so sloppy that I could press it fully in with my thumb. The inside of the t-cover had grooves where the belt had been riding. I am happy to report that the noise is gone, and were it not for this very forum, I would have thought that it was rod knock. I mean, it is loud and obnoxious sounding when that belt is flopping around in there. Anyhow, the key to this whole job is keeping track of your bolts and not doing more work than is necessary. The power steering pump lines don't have to be disconnected, there are easier ways than I did it to get the a/c belt off, and finally, I used a piece of cardboard and punched holes for each bolt. I was actually able to keep track of them, and had none left over. That's a first for me! Anyhow, if anybody is considering doing this job on a 3.2 sohc, I would be happy to share my knucklescraping insight to maybe save you a few minutes or hours. I am glad I don't do this for a living, I'd have lost my a$$.

Well, very glad to hear all this! I REALLY though (not sure I don't still think) I threw a rod or a bearing...

Not even 24 hours into owning my 98 trooper, after reading some of the posts, especially with the oil consumption and rods noise, and given that I had a little top clicking and a sometimes loud bottom deep "broken bearing" like noise, I priced the replacement of the timing belt and tensioner, stopped at auto zone and added gas treatment to the gas and seafoam to the oil.

About 20 miles later, on the highway it suddenly got REALLY bad! the noise got way louder much more disorganized (if that makes sense) and I really thought the engine was about to blow. Still had power and I made it home (just another few miles).

My biggest fear is that of putting another almost $400 into it just to find out it is indeed a rod or a bearing, though if it was a rod it probably would have shot through the hood by now and this thread got me hoping. Is it obvious when it is the tensioner? I guess the belt would be really loose? in other words, can I know if that's the case before I shell out the $$ for the parts on a totaled engine?

Could anyone confirm wether this issues is present in 3.5 1998 engines as well?

By the way if anyone wants to know, here is what I got quoted for the replacement by a local mechanic shop: $130 for the tensioner (they had to get the price from the dealer on this one) $70 for the belt and $160 in labor.

I could do it myself but I really think $160 is worth not having to deal with it for once... Question is: would it be safe to drive it back there (about 25-30 miles)? Is there a risk that belt will skip teeth and stick some valves on top of my pistons?

I will report back once I do something about it... Better be soon! I'll let you imagine how I feel: I just bought this last night, I love how it drives, feels and looks and now I can't drive it, I haven't even taken my wife for a ride in it yet!!!!
:eek2:
I guess if a tensioner is what made it such a good deal I can't complain too much....:)
Hoping that's what it is....

did you buy the trooper from a dealer? If so take it back and demand your money.

Yes it is a problem that happen from now and then.

whoever opens it up (the timing covers they should be able to tell if that is your problem).

did you buy the trooper from a dealer? If so take it back and demand your money.
No, It was a private seller, I'm not sure if he was aware "oh a rod is starting to go, I better sell it" kind of deal or not, but it behaved great and didn't really show a sign when I test drove it.

Giving it back would bring me to square 1, finding a deal I can afford and with an engine that didn't run dry... This seems to hold it's oil at least and it was a good deal, I can consider the $400 timing belt part of the purchase price and it's still a good deal if that's all that's wrong with it.

Yes it is a problem that happen from now and then.

whoever opens it up (the timing covers they should be able to tell if that is your problem).

Thanks a lot for your reply!

Keep us posted on what you find out.

Keep us posted on what you find out.

Sure will, it's at the shop now. I ended up taking it to a shop closer to home, I didn't feel comfortable driving it far. The estimate went up to $503(!!) but it includes replacing the water pump (might as well rather than doing the work again down the road)

Hopefully that's what it is. I'll know later on today or tomorrow. I'll keep you guys posted.

Well, a mid-way update:

The mechanic got to the timing belt and and tensioner couldn't see anything obviously wrong with it. From the first time he heard it, when I told him about the tensioner's issue, he looked at me listening to that knock with a face that spelled "you wish!", he had the same tone on the phone when he told me he got it opened, he said it's possible but not to get my hopes too high. He definitely thinks it's a rod but he's still going to try and replace it.

Bad news is the parts got to the shop at 5:30 on Friday and I won't know until Monday... What a weekend!

I'm loosing my optimism and started pricing engines... Holy Cow! almost as much as I paid for the whole thing with prices from $2500 (used) to $5000 3year 75000miles warranty remanufactured (for an engine that's still going to have all the same issues or needs babied to say the least)!!!

Is there any way to throw a Jeep (or any other worthy) engine in there?

If I do get a used or remanufactured engine, how hard is it to install it myself? ...not sure I can afford the additional $k's to have it installed. Any special tools needed other than an engine lift?

More Monday...

Ok,

Timing belt and tensioner were replaced. Knock is indeed internal, probably a rod!

My next few questions:

Used engine vs. engine rebuild: I hear they don't rebuild too well.
on the other end, with these engines being as buggy as they are what would I expect from a used engine?

A rebuild kit for the trooper is about $600 (see http://www.rpmmachine.com/enginerebuildkitsisuzutop.html) plus the machining costs (plus the $100+ for the service manual)
Cheaper than a used engine.

Can I get to the cylinders without taking the engine off the car? Should I consider opening the bottom too? What else should I think about?

I'm leaning towards rebuilding it myself. I guess my driveway will look like trailer-trash for a while :-) I can use all the help I can get, any pointers?

If that's what I do, I'll make sure to get fresh batteries for my digital camera and document the experience on the web.

Thanks in advance for any help.

Is there any way to throw a Jeep (or any other worthy) engine in there?
..

Feel bad that you actually think this way; that other engines are more worthy. In this particular situation though, I can see why you'd think that way - as it's obvious who ever had that truck before you didn't take good care of it, and probably ran it low on oil several times.

And you're probably new to this Isuzu world, so your best opinion would be based on what you've experienced thus far.

Not sure which is the best option, in your case, as I haven't had to cross that road yet. Just remember once that truck's rebuilt, same problem most likely won't happen again for a long time - as long as it's taken care of and full of oil.

Sorry, I didn't mean to bash this engine, just going by what I read mostly here...

You're right it is based on experience, My last car was an 86 Jeep cherokee, and has never let me down. lately, at 250000+ miles it started leaking oil majorly, and I can't tell you how many times I ended up dry with the rockers knock to tell me about it. Put oil back in and it still runs strong! oil changes at times just didn't happen, I really abused that car and it had been faithful to me. In fact, it still is, with looking at rebuilding the trooper I'll have to keep refilling the leaky (note it doesn't burn it, it leaks I don't even know where from) engine, push start it or replace the starter and keep using it until I can enjoy the leather of the trooper.

Not a smooth engine, not nearly as technologically advanced, not as much pickup but darn reliable. The trooper, I love how it feels and drives but my personal experience has been from smooth and silent to knocky in 1/2 day (50 miles total) to darn close to blown in another 1/2 day (30 miles) the scary thing is there was no warning! if I was 200 miles away I probably wouldn't have made it!

...other people's experiences... The forums speak. There is issues with it that are known flaws, no denying that! Many engines went from apparently good to blown in one trip I hear machining them isn't too good... It needs babied to say the least: "there there, let me brush your pipes from the inside, give you a nice seafoam bath, change that intake manifold gasket once or twice and check your oil every single time I fill the tank to be safe, especially on those hard highway miles when you're under such stress... at 10 mph above ANY speed limit it's what? 3100 Rpm? poor thing!!" (I wonder if that's part of the problem, maybe it needs to be driven harder than that)
...let's not deny it, it's almost a hobby and an expensive one at that. One I'm willing to join and be proud of, heck I'm about to rebuild it's engine myself and I'm going to enjoy it :-)

Again, don't get me wrong, I like it, I looked for one and bought it knowing all this because I like it so much. But you can see where that statement comes from. I am willing to baby it, I just wish it gave me a chance to do so. To me "worthy" includes reliable...

I'm sure you can understand that given an estimate of 3000+ for a USED engine and things like a spark plug coil costing $100+ each the thought of a CJ5 316 engine rebuilt to new specs for a fraction of the cost crossed my mind. (I know it's silly and would be a waist of a good SUV and a rebuilt engine at the same time)

I sure hope the rebuild makes it last a long time... I want to hope (And I'll make sure to ask and report back here) that the pistons they're offering are the upgraded ones...

Has anyone dug deep into this engine? I sure can use some pointers...

Don't apologize, you are correct in much of your interpretation; a lot actually.

To be honest, I'm not too keen on these 98+yrs of the 3.5L, or the 3.2L V6 DOHC engines either. The more I hear about them, the more I'm leary of them.

I do believe it is hit and miss; good engine/bad engine, oil burner/non-oil burner, etc.

I thoroughly believed that since they were an Isuzu engine they'd be as bullet-proof as my 97, 3.2L V6 SOHC - but that doesn't seem to be the case, because you do see people saying how often they have to constantly monitor everything.

Granted, I do check my oil level every other week, but I've never come close to even burning a quart in 3K miles, let a-lone a quart in 1K miles. And I don't want an engine that I have to baby down the highway, in regards to paranoia of oil usage.

I do a LOT of traveling, touring, etc, and the last thing I want to worry about is how fast the oil is being burned at 65mph.

If someone is driving 75+ miles per hour, that I can see having to check your oil, as you shouldn't be driving a heavy suv over 75 mph anyway.

I completely agree, and understand that one should check their oil regularly, especially during long-haul, over the road trips, but not every 200 miles or so, that's insane.

My whole point for liking Isuzu's is the good reliability I've had with my 2 Rodeo's - neither use (used) oil, and neither have had any problems related to intake manifold, exhaust manifold, etc. and both Rodeo's were the type of vehicles you could just jump into and drive and drive and drive without issues.

To this day, if I don't need the camper, or the bed of the truck, I'll take my Rodeo with over 136K miles on a drive cross country before I'll take the Dodge Diesel with only 75K miles.

I want to keep that same trust; and again, it just seems like it's too much of a hit/miss on the 98+ newer engines.

So I do agree with you for the most part.

I am in the middle of a timing belt tensioner replacement on my 94 DOHC 3.2L V6. I had the same loud disorganized knock as sciallo.

It sounded like it was on the passenger side of the engine. Placing a long screw driver to the timing belt cover and the handle to my ear (in comparison to doing the same on the enigine block) made me feel like the noise was louder from my timing belt area.

I pulled the left timing belt cover and sure enough with the engine running the timing belt was really loose and jumping quite a bit.

I found a kit with the tensioner pulley, timing belt and idler pulley online for a reasonable price, but I cannot find the Hydraulic push rod that pushes the tensioner pulley to make this whole thing work. Anyone that can help me find this part would be an absolute Godsend.

Please let me know if you have found this part and where you found it.

Thanks,
TroutFisher

I found a kit with the tensioner pulley, timing belt and idler pulley online for a reasonable price, but I cannot find the Hydraulic push rod that pushes the tensioner pulley to make this whole thing work. Anyone that can help me find this part would be an absolute Godsend.

Please let me know if you have found this part and where you found it.


Go the dealer for the tensioner mechanism. It is my understanding that this is the component that was revised by Isuzu (because of their common failure).


My last car was an 86 Jeep cherokee, and has never let me down. lately, at 250000+ miles it started leaking oil majorly, and I can't tell you how many times I ended up dry with the rockers knock to tell me about it. Put oil back in and it still runs strong! oil changes at times just didn't happen, I really abused that car and it had been faithful to me.


You got lucky... my best friend builds Jeeps and does motor swaps for a living, and while they are capable vehicles off road (with some modifications), the aren't known to be trouble free, to say the least. I have an uncle who has had 4, a YJ, 2 XJ's, and a ZJ. He liked the vehicles, but eventually quit buying them because he couldn't find a depenable one. Unlike Isuzu, they don't just have their '2 common issues', there's no telling what is going to fail, or when. Like most american cars, it's like playing roulette.

With the 3.2, the things to whatch for are the T-belt Tensioner and Hydraulic lifter ticking. Not big deals, just have the original tensioner replaced the first time you bave the T-belt changed (if done at the dealer, they should know to do that), and keep the oil changed with the proper viscosity synthetic, and you'll never experience these problems. As for rod bearings and rings, etc, the isusu motors are unusually durable and reliable (except for the GM I4 and V6, go figure), sounds like you just got one of the few. Of course, I don't know anything about the life of your particular truck...

If you don't want to rebuild (it's never quite as depenable for any motor), and don't have the bucks for a new motor, you might consider Ebay; I've seen a few used motors go for a little over a grand. With gas prices the way they are, you might consider an Isuzu 4jb1-T diesel swap. They can be purchased over seas for about $2500. Do some google searches, I've seen quite a few do it (one in a Jeep ZJ).

As for Isuzu's showing their problems on the forums, go visit some other vehicle specific forums (I frequent quite a few, Toyota, Honda, among others); suddenly you'll come to the conclusion that there is no good brand/model of car! Naturally, people come to these forums to find answers to their problems from other owners, keep that in mind...

With the 3.2, the things to whatch for are the T-belt Tensioner and Hydraulic lifter ticking. Not big deals, just have the original tensioner replaced the first time you bave the T-belt changed (if done at the dealer, they should know to do that), and keep the oil changed with the proper viscosity synthetic, and you'll never experience these problems. As for rod bearings and rings, etc, the isusu motors are unusually durable and reliable (except for the GM I4 and V6, go figure), sounds like you just got one of the few. Of course, I don't know anything about the life of your particular truck...


I've been done with the engine rebuild for a while now. Working great, but I still feel like I'm sitting on a ticking bomb. Just the fact that with every other car I had (Less complicated engines I guess) there would be a warning. For what I experienced and heard about the 3.5 isuzu, once you realize something is going wrong it's time to walk. I've had cars that would smoke, knock and piss oil across the country before failing, I don't see that happening with this engine. My trooper went from light knock to rod banging on the side of the engine crankcase in a matter of less than 100 miles.

The machine shop that machined my crankshaft (rpm-machine) had 34 in the shop with the same problem: journal #1 and that's just for that week, they said they are constantly getting those in!! They did some r&d and started modifying them (enlarging oil passages), now they are selling brand-new upgraded crankshafts from isuzu as an option. So I guess you can add this to the "known problems".

I made the mistake of going with lightwait oil for for just about 1000 miles on the rebuilt engine before realizing it was a bad idea, switched back to 20W40 right away and I kept burning oil still. It's now starting to slow down on the burning after about 5000 miles.

It just makes me nervous to be driving something this delicate.



If you don't want to rebuild (it's never quite as depenable for any motor), and don't have the bucks for a new motor, you might consider Ebay; I've seen a few used motors go for a little over a grand. With gas prices the way they are, you might consider an Isuzu 4jb1-T diesel swap. They can be purchased over seas for about $2500. Do some google searches, I've seen quite a few do it (one in a Jeep ZJ).


Done my research before rebuilding: 3.5L No way you're going to find on ebay for 1000 besides why would I want a used engine that has such issues!! who knows how they treated it and how long it would last. The hardest part of the rebuild was indeed getting the engine out then back in, a used engine wouldn't spare me that...

I would consider the rebuild WAY more dependable than a used engine (or new original-unupgraded engine for that matter). The cylinders didn't need machining, all seals and bearing were replaced the only thing that had to be machined down was the crankshaft which should pose be no problem with the matched oversized bearings. If I really wanted to I could have spent an extra ~$500 - $600 for a new one (!!) They did say that the pistons were the upgraded ones, though I didn't see any visible difference.

I did look for a diesel engine and would have loved it, but they are not easy to find and there is no swap kit: A lot of other stuff needs to be replaced: electrical and fuel system... I'm not sure I would be driving yet if I went that way...

My 2 Cents : Hey Trooper Fans .. not sure what my opinion is worth, but It possibly will help someone as this Forum partially helped me.

My 97 Trooper has been experiencing the valve tapping issue mentioned for quite some time. I tried adding Marvel Mystery Oil, SeaFoam, Rislone and then using a heavier weight synthetic oil. After trying all of these potential resolutions, I had brief timeframes where the ticking had stopped or became quieter, but after a few more miles, it would return. It would get louder and then quiet down .. then disappear. On start-up in the mornings, it was return. At this point I was convinced I would have to replace the lifter or Timing Belt tensioner.

So .. one morning on the way to work as the ticking progressively got louder, I had an idea. I thought to myself, the Forum mentioned could be due to carbon deposits. I typically drive to and from work on back roads and the trips are short, hardly ever getting it on the Highway. Well I figured if there's carbon or dirt build-up, Whatever it is causing the issue may dis-lodge if I drive it unusually hard.
I figured I'll either break the part, which will eventually have to be replaced anyway or maybe I'll get lucky and it will resolve the problem. I was pessimistic, but there weren't too many options left.

So I found a nice straight road and dropped it into 2nd gear, reving it up to around 5000 RPM's ... I let it hover around there for a couple of minutes ( I did shift into third but I kept the revs at around 5k rpm's). I continued to drive it hard like this for about 6-10 minutes. When I returned it to a "normal" driving mode (shifting back to 4th) I couldn't believe my ears. NO TICK!!!!!

So far it's been about 600 miles since the tick has subsided. I'm not sure if it will return, (Hope Not) but for now she's purring like she did the day I bought her!