Hotwire
NAXJA Forum User
- Location
- Spoke, BC, Canada
So, my oil pressure would be fine when cold then would drop to 0 on idle when warm. I did all the usual, changed the sensor... twice... and added a mechanical gauge. Both read 0 at operating temp at idle.
There was a split second rattle on cold start that worried me, but it was not consistent. Sometimes it would rattle others it wouldn't. It pushed me more towards a tear down.
I also pulled the oil pan, and saw what 230,000km with probably only 10 oil changes looked like.. there was 1/2" of sludge, carbon and general corruption in the bottom and coating the entire pan. I pulled the valve cover, and it was the same. It looked like black carbon crystals growing all over everything.
Out the motor came, and the teardown began.
I found that the cam its self was warn so bad that the bearing surfaces looked like dark gray granite. Some of the lobes have minor wear but the cam has gotta go anyways because of the bearing surfaces. The bearings themselvs looked the same.
The main bearings show wear, as do the rod bearings. The crank mains and lobes all show the same wear, so it needs a polishing. And new bearings all around.
The cylinders all look fine with no scratches, the pistons are the same. No cracks and the wrist pins are all tight in their bores. Piston #6 had a ring broken in 3 places .. so all new rings too. Of course a honing and good washing is in order too.
The block, and crank is going to the machine shop for a dip and to have cam bearings installed. I'm going to have them check the mains for alignment and concentricity / ovality.
So.. when it all gets back I will measure ID's and OD's, calculate and order what I need... This is fun... I hope... REALLY hope... That this fixes my problem and brings some youthfulness to my XJ
Does anyone have suggestions for cam upgrades?
Thanks for reading.
There was a split second rattle on cold start that worried me, but it was not consistent. Sometimes it would rattle others it wouldn't. It pushed me more towards a tear down.
I also pulled the oil pan, and saw what 230,000km with probably only 10 oil changes looked like.. there was 1/2" of sludge, carbon and general corruption in the bottom and coating the entire pan. I pulled the valve cover, and it was the same. It looked like black carbon crystals growing all over everything.
Out the motor came, and the teardown began.
I found that the cam its self was warn so bad that the bearing surfaces looked like dark gray granite. Some of the lobes have minor wear but the cam has gotta go anyways because of the bearing surfaces. The bearings themselvs looked the same.
The main bearings show wear, as do the rod bearings. The crank mains and lobes all show the same wear, so it needs a polishing. And new bearings all around.
The cylinders all look fine with no scratches, the pistons are the same. No cracks and the wrist pins are all tight in their bores. Piston #6 had a ring broken in 3 places .. so all new rings too. Of course a honing and good washing is in order too.
The block, and crank is going to the machine shop for a dip and to have cam bearings installed. I'm going to have them check the mains for alignment and concentricity / ovality.
So.. when it all gets back I will measure ID's and OD's, calculate and order what I need... This is fun... I hope... REALLY hope... That this fixes my problem and brings some youthfulness to my XJ
Does anyone have suggestions for cam upgrades?
Thanks for reading.
