Tampa_XJ
NAXJA Forum User
- Location
- Detroit, MI
Ok been trying to solve this clacking/rattling noise I'm getting on the XJ and I'm failing miserably thus far.
Info: 93 XJ 4.0/auto/231 with around 250K Miles on it 3" lift, 60psi oil pressure on start, runs between 25-40 once warmed up. Temps run fine, no other running issues.
Symptom: Produces a rattle/clacking noise when idling and is worse with the a/c on. Noise goes away as soon as you touch the gas. Sounds a lot like a rod knock.
Stuff done thus far: Dumped the oil and checked for metal particles and other tell tale signs of metal wear ( oil was clean). Pulled valve cover and checked lifters and rods for defects and such(all were fine and tight). Dropped oil pan to check for rod bearings even though my oil pressure was fine(all were tight and good considering mileage). Removed inspection plate and checked converter bolts(3 were tight 1 required a half turn). Checked for loose accessories, dented/bent exhaust and skidplates, etc.
My opinion: At first I assumed it was a bad rod bearing, but with my oil pressure there is no way it could be that. The fact that the noise only occurs at idle and goes away when on the gas also kinda makes me skeptical of anything internally. Usually the noise would increase at the same speed as the engine if it were a rod knock/piston slap/ or lifter tap. The noise does seem to come from the oilpan/tranny area.
Any opinions or directions to go would be greatly appreciated. To be honest the thing runs fine, I just can't deal with having a random noise that isn't supposed to be there.
Info: 93 XJ 4.0/auto/231 with around 250K Miles on it 3" lift, 60psi oil pressure on start, runs between 25-40 once warmed up. Temps run fine, no other running issues.
Symptom: Produces a rattle/clacking noise when idling and is worse with the a/c on. Noise goes away as soon as you touch the gas. Sounds a lot like a rod knock.
Stuff done thus far: Dumped the oil and checked for metal particles and other tell tale signs of metal wear ( oil was clean). Pulled valve cover and checked lifters and rods for defects and such(all were fine and tight). Dropped oil pan to check for rod bearings even though my oil pressure was fine(all were tight and good considering mileage). Removed inspection plate and checked converter bolts(3 were tight 1 required a half turn). Checked for loose accessories, dented/bent exhaust and skidplates, etc.
My opinion: At first I assumed it was a bad rod bearing, but with my oil pressure there is no way it could be that. The fact that the noise only occurs at idle and goes away when on the gas also kinda makes me skeptical of anything internally. Usually the noise would increase at the same speed as the engine if it were a rod knock/piston slap/ or lifter tap. The noise does seem to come from the oilpan/tranny area.
Any opinions or directions to go would be greatly appreciated. To be honest the thing runs fine, I just can't deal with having a random noise that isn't supposed to be there.