Hello,
Looks like I have some work ahead of me....
Its a 3.9L 1995 D I
The other day I noticed my engine when I gave it gas started making this vrmmmmmmmmm sound. Its a very faint sound. Not really a knock or tick. Of course engines do make sound when they speed up in rpms.... But this is deep. I had a friend do it while I was directly under the oil pan and I would say its coming directly from above the oil pan.
Who can offer some advice on doing this?
Do I need to pull the engine to do the rod and main bearings?
What else should I know.

 

Rod bearings, no. Main bearings, probably. On other engines, I've seen people "roll" the main bearings in with the crank still in place and the engine still in the car. I'd be prepared for that not working out.

 

We need to hear the sound, could just be a exhaust leak.

 

Spike,
I agree, but I have an exhaust leak! AHHHHH. I will try to get the sound....

 

I was planing on taking the engine out... When you say "roll" what dose that mean?

 

The bearings actually sit into it's cup semi-securly. The bearings have an indented end which secures it to the other bearing. If the indent becomes torqued and flattens, one of the bearings may get spun under or over the other bearing. You would definitly know if this happens. The noise will be a hard knock. If you perform bearing work, I would suggest useing a plasti-gauge first before purchasing bearings. Just simply drop the sump pan, remove the piston rod caps and bearings, then push the piston up a bit to remove the upper bearing without scratching or defaceing the bearings. Use the plasti-gauge on each piston side and cap side to determine actual bearing size needed. Perform each piston rod bearing seperatly from front to back. You can reassemble with the old bearings and keep on trucking until you are ready to perform the real repair. I say this because the bearings are flat with no oil grooves and I noticed that it causes wear to each component on both sides of the bearing. If you just drop in new bearings you will find that the piston rod and cap will still wiggle freely with a noticeable gap. I imagine the designers thought of useing this gap to allow oil to lubricate the bearing surfaces. However the wear obtained from running flat bearings causes wear to the actual components they were supposed to protect. If you pre-gauge, you can increase the tolerance and perform a better repair. If you just toss in new standard size bearings, you will still hear noise from the rods as they bang away. This engine was so poorly designed that it would be better to just drop it off at a machine shop and have them gauge and or turn down the warn parts and just drop in some oversized bearings. Good luck.

 

I know I will need to measure them. Otherwise I have no way of knowing if I need standard, .10 over, or .20 over. I think I will pull the pan, and measure the bearings. Then once I know what I need, I will drop the engine off at the machine shop and have them miss with it! Sure it will be costly but its a rover... It needs to cost an arm and leg.

 

You'd remove the main cap and you turn the crank in the direction that would allow the bearing to slide out, maybe helping it start with tool of some sort. Then you'd turn it the other way and try to slide the new bearing back into place.

 

That could work......