Wrist pins

I believe that my 4.0 in my 95 (which is actually a 93 motor with around 100k), has a wrist pins that needs replaced.

I have a sort of knock, its not all the time, its off and on at idle and goes away right now with more rpms. I've had this noise for about a year... (about 400 miles, mostly trail miles) and its progressively gotton worse. I think the problem is a bad wrist pin.

anyways, i've never heard anyone talk about a wrist pin going bad in the 4.0.

i'm not really looking forward to replacing it, would rather be looking for a 5.2 or 5.9 to swap in......

mac 'all about the benjamins' gyvr

Only one I've heard of was in an '89 I bought that had a blown oil pump. I swapped it to Joe Rosa and he got it running, but one cylinder has a knock and it isn't a rod bearing.

It can happen, but isn't usual.

well guess i'll pull the motor and see what the noise is for sure, it sure points to a wrist pin, if its bad, its be going bad for about a year now (only 500miles) and I've already blow one motor up, really dont have the desire to blow another up...

mac 'wish the 5.2 or 5.9 swap was affordable' gyvr

sounds like what i just went thru with my 99 4.0L..... piston skirt slap... sporadic knocking sound, never at cold idle or full temp idle... i would only hear it when the engine was partially warmed to about 110 degree.. (in my case it was when i'd leave work for lunch and again after work).. after soem wrangling with the dealer it was warranteed with only 73000 miles.. as it was explained to me it was a bigger issue with the early HO's up to around 94.. after that they started using some dry-film lube applied to the skirts to lessen the effects of the connecting rod trying to push the piston thru the side of the cylinder instead of up.. a wristpin would be pretty constant, and change as the engine warmed.. dont pull the engine. just the head and check the bore values... IIRC they told me the limit is .0025 out of round.... my worst cylinder was #2 at .0042 .. good luck with it..
mike

hmmmm....

well my old motor that i blew up before definately had what is referred to as pistion slap. that motor was a 95, the pistion slap in that one wasn't ever a problem, this noise is definately a knocking noise and is different than the piston slap noise. you can heard it at idle now at any engine temp and if you rev the motor up a little, the noise pretty much goes away....sooooo

since this jeep is not daily driving and its been pulled before, i'm not all worried about pulling it again, as its not a huge deal to me.

mac 'roller rockers? lol' gyvr