Oil pump replacement....

[BronKitis]

Ok..... I finally put an oil pressure gauge on Tonto and the results were not good.... At operating temp, I was only getting between 8-10psi at idle and the most I got while running throttle up was between 45-48psi....

How much of a pain is it to drop the pan on these things so I can replace it? How high does the motor need to come up? Can the tranny stay connected? Not really looking forward to this job but if it will help my lifter tick then it will ALL be worth it! Thanks for the help guys!

 

[adsm08]

If I was doing it I would pop the drive shafts, undo the trans mount bolts, undo the engine mount nuts, and then drain the oil, pull the pan bolts, and hook a cherry picker to it and just pull it up until the pan fell out.

Then again, on a 2.9 I would pull it out and do the cam bearings too. Those are probably just as much responsible for your noises.

 

[BronKitis]

So, are you saying that my low psi may be caused soley by the camshaft bearings? That maybe my oil pump isn't bad but that the port in which I'm recieving my psi reading is being directly effected by said bearings? No bueno.... If that is indeed what you're saying...

How could I confirm that my pump IS bad before I do all this work and spend all my retirement fund? lol

 

[GentleRF]

Cam bearings are hard to plastigauge whereas rod and main bearings are relatively easy. The crank bearings (rods and mains) are the first to get worn due to the higher loads they carry. I had one engine with rods and mains down to the copper underlying the babbit. The crank itself didn't have any issues and miked out within tolerance for new bearings. I put some in, plastigauged them and ran that motor for another 120,000 miles.

 

[adsm08]

So, are you saying that my low psi may be caused soley by the camshaft bearings? That maybe my oil pump isn't bad but that the port in which I'm recieving my psi reading is being directly effected by said bearings? No bueno.... If that is indeed what you're saying...

How could I confirm that my pump IS bad before I do all this work and spend all my retirement fund? lol

The pressure port is before the cam bearings in terms of oil flow, so it's likely that you do need a pump. The 2.9 has oiling issues in the top end though, and so I would just do them because they are cheap and a common cause of top end noise.

The cam bearings and rod bearings will usually wear out before the crank mains because the they take more abuse. The cam bearings are smaller around and spin twice for each crank rotation. The rod bearings also have a smaller surface area and take the direct hammering effect of the power strokes.

 

[Andy D]

Yah that was the end of the 360 v8s I had in the jeeps. Cam bearings , then the thrust bearing on the crankshaft. Replacing the oil pump was a PITA job and it didn't fix anything . Both require a good machine shop . I would be looking for a good used Ranger or Explorer 4.0 and then get a 5spd . I really like the way the stock 94' drive line behaves in the Rat. It deserves a way better frame and body than the one it is in.

 

[BronKitis]

The pressure port is before the cam bearings in terms of oil flow, so it's likely that you do need a pump. The 2.9 has oiling issues in the top end though, and so I would just do them because they are cheap and a common cause of top end noise.

The cam bearings and rod bearings will usually wear out before the crank mains because the they take more abuse. The cam bearings are smaller around and spin twice for each crank rotation. The rod bearings also have a smaller surface area and take the direct hammering effect of the power strokes.

Though your advice is best, I think I'll slap a pump in to see what happens and start making plans for a 302 swap. If the motor goes before then it will only add to my ambition I'll see about uploading the short video I took yesterday from my phone.