97 Tracker knocking idle only smooth running

She runs great all the way around but when she's sitting you can hear her knocking. I can't for the life of me figure out what is wrong.
I change the oil every 3K and I'm usually the only person in the vehicle 50% of the time and she's never loaded with junk or towing. Now for some reason she knocks and sometimes it is worse and sometimes almost non existent. When I put it in PARK it seems to lessen. In gear with the brake on it worsens. If you have an idea as to what this is please let me know! She a four banger with an automatic tranny four door with 90K on it.

Thank you !

try checking to see if the flywheel bolts to the convertor are loose, or if the flywheel itself is cracked around the bolts

try checking to see if the flywheel bolts to the convertor are loose, or if the flywheel itself is cracked around the bolts


Thanks HAWG ......... I'll check it out. The problem seems to change all the time in intensity. Sometimes you can hardly hear it. Other times it is fairly loud. My mechanic buddy was under the vehicle and I was changing gears to make the sound change. He originally thought it was something simple like an exhaust problem but he got up from under the TRACKER and just looked back into the engine area and said " it sounds like it is coming from the center of everything ....".
So what you are suggesting makes some sense.
We'll check it out.

ZORGON

let me know how you make out

Um yeah an Automatic transmission having a flywheel?
An automatic transmission has a flex plate not a flywheel.

Where is the knocking comming from the engine or the tranny.

Is your motor rocking in the engine bay.

if your sitting in the cab is the sound in front? to the rear? under you?

Um yeah an Automatic transmission having a flywheel?
An automatic transmission has a flex plate not a flywheel.

Where is the knocking comming from the engine or the tranny.

Is your motor rocking in the engine bay.

if your sitting in the cab is the sound in front? to the rear? under you?

Greetings,
One mechanic friend thinks the sound is coming from the middle of the engine .......... another mechanic friend says he thinks it is coming from the head of the engine........ originally we thought it was an exhaust problem where it is bumping up against the frame.

The engine does not make any abnormal sound even when you raise the RPM a tad with it sitting in PARK or DRIVE. It does make less noise in PARK. Running down the road .......... no noise. No missing no bucking nothing.

Only when idle can you hear anything abnormal and it does change in intensity from time to time.

viperh I work for a dealer and the correct name is flywheel part number 96058097 with a 3sp auto 91172390 with a 4sp auto. have not heard them called flex plates in years.

viperh I work for a dealer and the correct name is flywheel part number 96058097 with a 3sp auto 91172390 with a 4sp auto. have not heard them called flex plates in years.

You may be right. I don't own an automatic anything but On LS1Tech and any other automotive forum I have been on refer to automatics having a torque converter and a flexplate while manual cars have a clutch (pressure plate, clutch disk, throw-out bearing.) and a Flywheel. You threw me off when you said flywheel for automatics thats all.


Back on point.
Your best bet is to buy a mechanic's scope for 10 bucks and place it at diffrent spots on the engine. (make sure the engine and exhaust aren't just rocking and hitting anything) then put idle the car and and place the scope untill you find out where the knocking is.

You may be right. I don't own an automatic anything but On LS1Tech and any other automotive forum I have been on refer to automatics having a torque converter and a flexplate while manual cars have a clutch (pressure plate, clutch disk, throw-out bearing.) and a Flywheel. You threw me off when you said flywheel for automatics thats all.


Back on point.
Your best bet is to buy a mechanic's scope for 10 bucks and place it at diffrent spots on the engine. (make sure the engine and exhaust aren't just rocking and hitting anything) then put idle the car and and place the scope untill you find out where the knocking is.

Probably the best thing to keep in mind is that the vehicle does not make any abnormal sound(s) going down the road. Nothing. She runs perfectly, shifts perfectly and there are no misses or shakes or anything.
Just when she's sitting at idle do you hear the knock sound. I change my oil every 3K and I drive like an old lady. The 4 wheel drive is working just fine as I've put it into that mode and road around the block a few times to check and see if something went amiss with the transaxle. It is the strangest thing. One of the next things I'm going to do it crawl under the nose of the Tracker to see if I can find something loose. It could be something silly like that but .................. unlikely. I have to rule it out. I was hoping it would be a common problem with this particular vehicle. I have to keep at it as I cannot have this develop into something more serious and cripple the TRACKER from running for any length of time.

Zorgon: Abroken flywheel will cause a noise that sounds almost like a rod knock at idle. Pull the cover on the bottom of the convertor housing and take a light to look up in there, and see if any of the bolts that hold the convertor to the flywheel are loose, or if the flywheel is broken. this will not cause the trans to shift improperly.My only other thought is carbon on top of the piston.

Zorgon: Abroken flywheel will cause a noise that sounds almost like a rod knock at idle. Pull the cover on the bottom of the convertor housing and take a light to look up in there, and see if any of the bolts that hold the convertor to the flywheel are loose, or if the flywheel is broken. this will not cause the trans to shift improperly.My only other thought is carbon on top of the piston.


What on earth would cause a flywheel to break? I'll definitely look into this for sure but man o man I just can't imagine what event would make that type of component break. Would a hit to the vehicle do that? Thanks for the information. I'll post my findings on this.

if the bolts did come loose enough it will cause it to break. remember it is not as heavy as one on a manual trans car.

I have a 97 tracker that is knocking and narrowed it down to the crankshaft timing belt gear. The woodruff key is worn causing the gear to knock. The pully (bolt) that holds gear on was tight. You can see pictures of this arrangement at auto zone.com. It sounded like the middle of the engine was knocking. I used a piece of metal electrical conduit as a stethoscope to track down noise. I have 134000 miles on vehicle. Not sure if this is your problem but i fiqured i would share. I'm in the process of repairing.:grinyes:

Thank you for the information! Sometime today my mechanic friend and I are going to quickley loosen the power steering belt to make sure that it is not the source of the knock. She does not make any type of abnormal sound when the idle is raised even a tad. Nothing. Only at the lowest RPM does this sound appear. Usually power steering units whine and growl when they go bad but some TRACKER owners have told me there is a censor in there that makes a knock sound when bad. If the power steering unit is ruled out I'm going to have to go after the timing belt area.

Thank you again!

ZORGON
:)

Well... I got my knock fixed. The timing belt gear on the crankshaft was very loose due to the woodruff key being damaged. The slot on the crankshaft where the woodruff key goes was trashed. The only cheap fix was to weld the gear on the crankshaft or put set pins in. I had a friend weld it but it didn't hold. I finally drilled thru the crankshaft gear in two places right into the crakshaft and put two 1/8 roll pins in. I recessed the pins so it wouldn't damage the timing belt. I used a new gear and woodruff key. I searched the internet and found out this is a common problem. It seems the bolt that holds the gear to the crankshaft bottoms out and the gear eventually works its way loose. If you even hear a small knock look at the crankshaft pully to see if it is wobbling. If it is get this fixed right away. Mine was also causing a p0300 code mutiple cylinder missfire. The crankshaft sensor is right below this gear. The gear has tabs on it that work with the sensor. New gear $35. Woodruff key $2. Roll pins 28 cents each. Good drill bit $3. I'm a little slow so it took me about 6 hours to finish. I had to take radiator and fan blade out to have enough room.:rofl:

Thanks for the information. This sounds dismal at best. I'm sure I'm having the same problem but I can tell you the vehicle runs pretty darn well. Today we take the radiator out and take our first look.

I'll let you know and thanks again! :frown:

I have a 95 tracker and it stalls,though i just havent had a chance to try to fix it yet i thought i would try to turn on my air conditioner when it tries to stall cause i noticed my rpms jumped up when i turned it on but my a/c didnt work coincidentally for the first time at that time.So now i have 2 things to fix.Does anyone know what part boosts the engine when turning on a/c. Probably the computer HUH! I did adjust the air screw last fall and it worked great for about a month and a half and was surprised when it started stalling again.THANK YOU!