2.5 engine noise (with videos)

[Tim_with_the_tj]

Hey y'all. New guy here. This is my first time to actually own a Jeep and not just mess around with a friend's. Found a good starting platform, but she needs a few things of course.

I searched the forum and it seems like I may have the typical timing chain/tensioner noise on my 2.5L engine. It's a 1997 with 160,xxx miles. Overall the engine runs good and seems smooth. I drove it 2 hours on the freeway to get her home. No complaints other than the whopping 145 ft lbs max torque, haha. Here's a few videos below of the noise.

I would appreciate if some of you could confirm this timing chain/tensioner hunch before I tear into the front of the engine. The sound is definitely happening in the front part of the engine. You can hear it much more loudly when you listen underneath the oil pan towards the front of the engine vs towards the rear. What do you think?

Hopefully my revving the engine by hand wasn't too weird on the third video. Sorry about the wind noise from the fan.

Here's the kicker: previous owner says he replaced the chain and tensioner within the last 6 months. I don't know if maybe he did something wrong with the tensioner...every other repair on the Jeep he claimed to have made was indeed true because I was able to visually verify those (I don't think he lied). Thoughts on this noise? I bought this Jeep knowing it had this noise because I'm rolling the dice for it not being a rod knock, etc. The thing just runs too good for that to be happening IMO.

Thanks in advance.

 

[tr21triton]

in the video from the bottom it almost looks like your fan blade is wobbling .

 

[Tim_with_the_tj]

in the video from the bottom it almost looks like your fan blade is wobbling .

Fan looks fine in person. Might be a weird thing with the frames per second in the video. There’s no play in the fan while stopped either. Grabbed it and tried to see if there was any slack. None.

 

[Tim_with_the_tj]

Tomorrow I’ll pull off the serpentine belt and start her up to see if the noise remains. That’s easy enough to try first.

Could also be lifter noise, but I haven’t experienced that noise vs. timing chain noise on these motors… so I’m not sure. Maybe I should just change the oil and sub 1 quart ATF. Might be worth a try before removing the front cover. If it doesn’t quiet down then it’s probably not lifter noise.

 

[TJ4Jim]

Tomorrow I’ll pull off the serpentine belt and start her up to see if the noise remains. That’s easy enough to try first.

Could also be lifter noise, but I haven’t experienced that noise vs. timing chain noise on these motors… so I’m not sure. Maybe I should just change the oil and sub 1 quart ATF. Might be worth a try before removing the front cover. If it doesn’t quiet down then it’s probably not lifter noise.

It's your timing chain, sounds just like my 2.5, stop at HF and pick up a mechanics stethoscope. Lay the tip on the timing cover and you will hear it. Not uncommon in the 2.5's.

 

[Tim_with_the_tj]

It's your timing chain, sounds just like my 2.5, stop at HF and pick up a mechanics stethoscope. Lay the tip on the timing cover and you will hear it. Not uncommon in the 2.5's.

Right on. I feel like that’s probably what it is, too. I’m just making sure at least someone else thought the same before I tear it down, so thanks.

 

[TJ4Jim]

Right on. I feel like that’s probably what it is, too. I’m just making sure at least someone else thought the same before I tear it down, so thanks.

They tend to sound just like a 4 banger diesel.

 

[Tim_with_the_tj]

They tend to sound just like a 4 banger diesel.

I thought the same thing. The whole time I’ve been driving it and it runs good. Just so loud! Haha.

 

[TJ4Jim]

I thought the same thing. The whole time I’ve been driving it and it runs good. Just so loud! Haha.

Do a new harmonic balancer when you swap the chain.

 

[Tim_with_the_tj]

Do a new harmonic balancer when you swap the chain.

Any advice on brands for good replacement parts?

 

[TJ4Jim]

Any advice on brands for good replacement parts?

The set I used was a Melling.

 

[Fughuert]

This is a broken timing chain tensioner that led to timing chain snapping in half. Good news is you can drive it without worry since it’s a non interference engine.

The previous owner replacing the chain may have happened but he might’ve missed one of the plastic tab tensioners that go to the cover, it’s different from the 4.0.

 

[Tim_with_the_tj]

This is a broken timing chain tensioner that led to timing chain snapping in half. Good news is you can drive it without worry since it’s a non interference engine.

The previous owner replacing the chain may have happened but he might’ve missed one of the plastic tab tensioners that go to the cover, it’s different from the 4.0.

Sounds pretty similar…a little more rattling than mine. Mine sounds more like a loud tapping or knocking. Thanks for the video. I have some things to take care of before I can actually tear into this thing. I will definitely keep the thread updated with what I discover.

 

[Tim_with_the_tj]

Took off some parts today, but need get a harmonic balancer puller to finish getting the cover off. The puller I had in my toolbox is missing the piece that goes on the end (pointed piece, shaped like a top).

I did notice I have one noisy pulley. That isn’t what’s making all this racket, but it doesn’t help either.

Hopefully I’ll have time to get this crank pulley off tomorrow and take a look under the timing cover.

 

[Tim_with_the_tj]

Got the cover off. Here’s what I found… the plot thickens.

Any suggestions for what to do next?

 

[Tim_with_the_tj]

Removed the valve cover to take a look around. Here's what I found. Would you guys say this is excessive?

 

[Tim_with_the_tj]

Could anyone tell me if this is normal for the rockers to be this loose? Seems bad. I realize the valve clearance is non-adjustable by design…but this has got to be making noise when running, right ?

 

[fourpointzero]

I know your jeep is not a six cylinder but, I've been watching these types of videos for years on various forums and don't believe anyone has resolved that rattle with their inline 6. Can't say Ive watched anyone do the same with their 4cyl. Maybe you'll have a different outcome?

My reason for chiming in is because my TJ also has this darker rattle noise that seems to be coming from the lower part of the engine. I've got almost 200 K on it and I drive hundreds of miles at a time. Just did 150 round-trip last night, no problems. Same last weekend.

I honestly believe some of these older Jeep engines just happen to be noisier than others. I've got no oil burning issues, no compression issues and no odd smells from the exhaust, including no smoke. I ultimately decided to just drive it till it dies. After all, some engines eventually fail. Or not. These are cheap to replace. When the time comes (if it does) I'll get a Jasper. I've got a buddy with a 1989YJ. He replaced his original with a new Jasper. It been over 40K miles and a handful of years, no issues.

I'm going to follow this thread because I'm curious to see what your outcome is. I wish you success! Because it is one hell of a mystery, to me.

EDIT: the sound TJ4Jim posted is much different than the rattle you have. I believe you noted that too.

 

[Tim_with_the_tj]

I know your jeep is not a six cylinder but, I've been watching these types of videos for years on various forums and don't believe anyone has resolved that rattle with their inline 6. Can't say Ive watched anyone do the same with their 4cyl. Maybe you'll have a different outcome?

My reason for chiming in is because my TJ also has this darker rattle noise that seems to be coming from the lower part of the engine. I've got almost 200 K on it and I drive hundreds of miles at a time. Just did 150 round-trip last night, no problems. Same last weekend.

I honestly believe some of these older Jeep engines just happen to be noisier than others. I've got no oil burning issues, no compression issues and no odd smells from the exhaust, including no smoke. I ultimately decided to just drive it till it dies. After all, some engines eventually fail. Or not. These are cheap to replace. When the time comes (if it does) I'll get a Jasper. I've got a buddy with a 1989YJ. He replaced his original with a new Jasper. It been over 40K miles and a handful of years, no issues.

I'm going to follow this thread because I'm curious to see what your outcome is. I wish you success! Because it is one hell of a mystery, to me.

EDIT: the sound TJ4Jim posted is much different than the rattle you have. I believe you noted that too.

Noise is resolved!

Thanks for your reply. I just finished up working on this yesterday evening. I will post exactly what I did during this process for you and anyone else in the future that comes across this. Maybe it will help someone out.

So picking up where I left off:

After verifying all the timing chain set and tensioner was new and correctly installed I reassembled the front timing cover. It’s a good thing I checked this, because when removing the fan I was able to remove two of the four bolts with only my fingertips. Wow. A few of the timing cover bolts were not tight enough in my opinion either.

I also installed a new harmonic balancer. The old balancer looked fine, but I figured why not. If I’m gonna remove it I’ll replace it with a new part.

I reassembled the rocker arms/pivots/lifter/push rods. Then I put on a new valve cover gasket (because once again, why not) and reassembled the valve cover.

I decided I would try running 1 qt of automatic transmission fluid in the engine with some new oil. This seemed easy enough to try…the thought process being that maybe it was a sticking lifter or something.

I drained the engine oil, left the old Mopar filter in place, then added 1 qt ATF with about 3 qts 10w30. All store brand fluids. It’s worth noting that even though the OP said he’d changed the oil recently, the oil that drained out was black and seemed a little bit thick. There was also some slight golden glitter in the oil…very fine particles. Nothing that worried me too much.

After adding the new oil and ATF, I cranked her up…. And to my surprise the engine was quiet now. I ran the Jeep for a few minutes in the garage then took it for a spin, about 10-15 mins around the backroads. Got back home and she was still running quietly. Good news!

Bad news was I had a significant oil leak coming from the oil pan at the front timing cover (where the RTV didn’t seal correctly). The provided two piece gasket kit for the timing cover did not fit correctly at the front of the oil pan. I used RTV and I did a poor job with it by tightening it too soon instead of waiting an hour then re-tighten. At this point I figured I would install a new oil pan gasket because you can get a one piece oil pan gasket that covers the lower timing cover/oil pan area as well. My oil pan gasket was the suspect of a leak at the rear anyway.

So I drained the oil and ATF from the engine (15 mins of run time) and it was already black. Wow. After removing the oil pan I did not discover any chunks of metal laying in the pan or any broken piston skirts etc. The bottom end looked fine. The goop I found in the bottom of the oil pan did not look fine, though. Haha. I cleaned out the oil pan, installed the new oil pan gasket (had to trim slightly to make it fit correctly at the rear), then re-installed the pan.

After putting on a new oil filter I filler her with fresh engine oil 10w30 and started her up. She runs good! No excessive noise and no leaks. The oil on the dipstick remained new and clear-looking after 30 mins of run time. I think the engine is clean now and seems a lot happier. The oil pressure gauge saw a very slight increase vs before. I had some pictures of the gauge before to compare with.

I know this is long, but maybe it will help someone. Start simple and go from there. I’ve learned a little about this engine in the process which is cool.
I’ll post some videos below in the next post

 

[fourpointzero]

Noise is resolved!

Thanks for your reply. I just finished up working on this yesterday evening. I will post exactly what I did during this process for you and anyone else in the future that comes across this. Maybe it will help someone out.

So picking up where I left off:

After verifying all the timing chain set and tensioner was new and correctly installed I reassembled the front timing cover. It’s a good thing I checked this, because when removing the fan I was able to remove two of the four bolts with only my fingertips. Wow. A few of the timing cover bolts were not tight enough in my opinion either.

I also installed a new harmonic balancer. The old balancer looked fine, but I figured why not. If I’m gonna remove it I’ll replace it with a new part.

I reassembled the rocker arms/pivots/lifter/push rods. Then I put on a new valve cover gasket (because once again, why not) and reassembled the valve cover.

I decided I would try running 1 qt of automatic transmission fluid in the engine with some new oil. This seemed easy enough to try…the thought process being that maybe it was a sticking lifter or something.

I drained the engine oil, left the old Mopar filter in place, then added 1 qt ATF with about 3 qts 10w30. All store brand fluids. It’s worth noting that even though the OP said he’d changed the oil recently, the oil that drained out was black and seemed a little bit thick. There was also some slight golden glitter in the oil…very fine particles. Nothing that worried me too much.

After adding the new oil and ATF, I cranked her up…. And to my surprise the engine was quiet now. I ran the Jeep for a few minutes in the garage then took it for a spin, about 10-15 mins around the backroads. Got back home and she was still running quietly. Good news!

Bad news was I had a significant oil leak coming from the oil pan at the front timing cover (where the RTV didn’t seal correctly). The provided two piece gasket kit for the timing cover did not fit correctly at the front of the oil pan. I used RTV and I did a poor job with it by tightening it too soon instead of waiting an hour then re-tighten. At this point I figured I would install a new oil pan gasket because you can get a one piece oil pan gasket that covers the lower timing cover/oil pan area as well. My oil pan gasket was the suspect of a leak at the rear anyway.

So I drained the oil and ATF from the engine (15 mins of run time) and it was already black. Wow. After removing the oil pan I did not discover any chunks of metal laying in the pan or any broken piston skirts etc. The bottom end looked fine. The goop I found in the bottom of the oil pan did not look fine, though. Haha. I cleaned out the oil pan, installed the new oil pan gasket (had to trim slightly to make it fit correctly at the rear), then re-installed the pan.

After putting on a new oil filter I filler her with fresh engine oil 10w30 and started her up. She runs good! No excessive noise and no leaks. The oil on the dipstick remained new and clear-looking after 30 mins of run time. I think the engine is clean now and seems a lot happier. The oil pressure gauge saw a very slight increase vs before. I had some pictures of the gauge before to compare with.

I know this is long, but maybe it will help someone. Start simple and go from there. I’ve learned a little about this engine in the process which is cool.
I’ll post some videos below in the next post

So cleaning it out, old school style, with 1 quart of tranny fluid "fixed" the rattle? Or do you believe it was a replacement part? Correct me if Im wrong, but you didn't do anything up top except check it and replace the valve cover, right?

Heck, if all it took was a thorough removal of gunk, then I'd be shocked. I'm due for an old change I'd do the same but I tried mystery motor oil years ago and I didn't do shit. I will say that my TJ, after a long drive, (ei. last night for example) it's often relatively quiet in comparison to when it starts and sits for approx 3 min, when I begin to hear the rattle.

Ya gotta videos of the before and after. That's wild if its just a matter cleaning.