Engine Knock on Cherokee 4.0

The guy 'repairs' your engine and then it produces even more noise than before and he blames the top end?.. lol.. he has you fooled for sure.. take it to somebody that truly knows what they are doing before you pay out anymore.. it is true that if you repair half of an engine, it can put more strain on the rest, but it would take more than a few seconds for that to become apparent.. good luck.. you may get a 0 miles engine out of this if you continue to let your friend work on it, but it will cost you dear..

-- History is only the past if we choose to do nothing about it..

Did he bore out the cylinders and install new oversize pistons? Was a torque/honing plate attached to the block when "fitting" the pistons to their cylinders? I think you might hear piston slap maybe? Although I think it is heard more with the engine running. :-) Or possibly exhaust leak from a cracked exhaust manifold? Or possibly a cracked driveplate or flexplate? just some thoughts! good luck, dave

Ouch!

Sure sounds like buddy screwed up big time.

The last time I 'heard' something like that, I helped the owner take it apart and fix it right.

The engine had a knock and went for a 'cheap' bottom end rebuild.

He ended up needing a new crank because the bozo that put it together forgot to put the journal caps back in the right place.

I couldn't believe the noise it was making, so we ran a stethoscope on it and it appeared to be knocking all over the bottom end.

It was!

Only 3 bearing caps were on right, the rest were mixed up and on backwards.

I mean crap, all the caps and connecting rods and main bearing caps were numbered even. The fool couldn't even follow the numbers.

When all else is the same and the noise changes, look at the 'repair', don't let anyone give you a snow job to cover up incompetent work.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

John C wrote:

A 4.0 that needed to be taken apart after 35k miles? Almost unheard of.

Was it beaten mercilessly during it's life? Mine has more than 100 thousand miles more than that and it sounds great.

I agree with you Clem, I've owned 5 Cherokees (not counting cj5, cj7, yj and the cj8 I still have) since they've come out and I've always gotten over a

100K on all of them. That 4.0 and the older 4.2 (258) engines are bullet proof. (my cj8 has 182,000 on the 258 inline and it ain't slowed down a bit) Never any problems. Keep the oil changed between 3000 & 4000 miles and you're good to go.

Ol' Reb

Not knowing how loud the sound was or what it sounded like.... could it be wrist pins?

Thats my luck! car has done genuine 35000 miles rest of the car is mint inside and outside, I saw the wear in the bearings myself.

John

First the knock was a loud single or double knock only when the starter dis-engaged, but following the new bearings it was a sickly loud constant knocking so bad that my mechanic only let it run for a few seconds before turning it off.

That is a bit abnormal to say the least, almost like there was something wrong right at the beginning. As for luck, you could look at this as a golden excuse to consider installing a stroker kit... make a 4.5 or 4.7 out of it.

We got to the bottom of the problem, the bolts on the torque converter were working loose, five new ones and all is well.

John

glad it was simple and also solved. :-) thanks for the update! later, dave AKA vwdoc1