Engine sounds like a diesel

[broncoguy75048]

Hi-
My 95 GC with the 4.0 liter is making interesting noises. The best way to describe it is that it sounds like a diesel. It's not super loud, but it's definitely got that diesel "knocking" sound.

I have recently run some engine flush through it and changed the oil. I did the flush because I changed the exhaust manifold a week ago, and after looking inside the intake manifold, and also checking under the oil cap, I saw a LOT of crud build up.

So, anyone have any thoughts on the diesel?

[GrCherokee]

Could be a gasket of the exhaust manifold bad.

[Caribbean ZJ]

its typical of the 4.0 I6. Keep ur oil level up & you should be safe. Some say changing to a heavier oil will help

[YtseJam454]

Skirtless pistons and a bad boring bar caused this noise. It's piston slap. Mine has 230,000 original miles on it and doesn't burn a drop! It's noisy but strong.

[broncoguy75048]

Piston slap does not sound good. That can't be "normal", can it? I just got back from a 400 mile round trip with no problems, but I am concerned about it.

[YtseJam454]

Yes, it is considered normal in these engines. People have used Lemon law on them because some of the earlier ones were so noisy.

[broncoguy75048]

Hmm.. Interesting. I guess I won't worry about it, then, since it appears there's nothing I can do about it, and you seem to have a lot of miles on yours with the same problem. Thanks for the replies.