I'm a newbie to this site so please bear with me. I did a search and didn't find much.

My 1994 4.0L Cherokee Sport 4WD sounds like a diesel engine. Seems to run fine and there is power. It's slowly been getting worse over the past year or so. I'm thinking it's a stuck valve or something. I read a little on here about lifter till, and I'm not sure what that is. The noise changes with engine speed and still sounds the same while driving. Here's a video of what it sounds like.


Any help and advice would be greatly appreciated.

The specs are as follows:
Stock 1994 4.0L
200,000 miles
Regular oil changes.
Has a cracked exhaust manifold.
Been pretty rough on this beast (a few cross country trips with a large trailer).
Hasn't been driven much all summer as my motorcycle is my main transportation.

 

Check the torque converter bolts sometimes they get loose and can cause a similar noise. The knocking sounds pretty severe from the video, I have also seen a broken piston skirt cause a knock but the jeeep will still run fine.

My 96 with 211,000 miles has some knocking which I suspect to be lifters, but it sounds different that what is in your video.

 

I had a s-10 that would sound like a diesel. It was the timing chain and it sounded just like yours just not as bad. But I don't know if it would be the problem with these engines.

 

It is hard to tell from the video, but if the noise is the same as engine speed it is a lower end noise. If the noise is twice as fast as engine speed it is an upper end noise. It sounds like a lower end noise to me. I would get a stethoscope with a long probe and listen in different areas, such as the timing cover, oil pan, side of the block ect. see where the noise is the loudest and you probably are in the area of the source of the noise. Let us know what you find.

 

Thanks guys. I'll give that a go and see what I come up with.

Joshua

 

I vote for a stretched timing chain slapping the cover.

 

Oooh...timing chain. That would be an easy and cheap fix, right? I'm f'ing broke so I hope it's something easy to fix. Thanks....let's hope it's that.

Joshua

 

The mechanics stethoscope might help you pinpoint where that noise is coming from.

 

I don't have a stethescope, but I'll try the screwdriver to the ear trick. Hoping to get it on a lift and do that later. The sound is coming from the top or front of the engine....so let's hope it's easy to pinpoint.

Joshua

 

just a thought oil or knock? probably a time chain

 

If it is the timing chain, do I need to replace the sprokets as well?

Joshua

 

Replace the whole assembly... crank sprocket, cam sprocket, and chain... I think if you dig around, there are some performance ones out on the market...maybe even a belt drive, it's been awhile since I looked....

 

Thanks for the advice, but it turns out it's a bad water pump. Bearing is gone, pully is wobbly, there's a bunch of aluminum and steel shavings in the radiator (and probably in the engine). But it doesn't leak any coolant...odd. The noise is the rotating part of the pump scraping away at the pump housing.

Now I just gotta figure out if this is something I can change, or take it to a shop.

Thanks.

Joshua

 

Water pumps aren't too bad to do yourself... Check the Tech. Write-up section, Belto has a write up on when he did his...

 

Excellent. Thanks.

Joshua