Oil Pressure!!

Ok I have an 84' CJ7 w/258 I-6. I have noticed when cold the oil pressure is at about 50psi, then once it warms up, even a little, unless you keep your foot on the accelerator the pressure drops to NOTHING! I have an after-market guage that reads the actual pressure(not electrical signal). The oil is clean and there is what looks to be a new FRAM filter on. I am suspecting the pump and/or the main and rod bearings might be the culprit. There is no glitter on the dip stick, and no real niose coming from the engine. Could I get away with just a bearing and pump job, if so, could I do everything with the engine still in the jeep?:banghead:

First thing you might want to try is another oil pressure gauge, to make sure the aftermarket one isn't bad.

If that's good then you're looking at a new oil pump. I'd think there is plenty of room in there to do it with the engine in.

hi ya gtmud Long time no-see

Is it carb'd or injected??

If it is carb'd then have a look at the mechanical fuel pump. if the diaphram is bad, fuel can dilut the oil and the viscosity is thinner. Not as likely to happen if it's injected.

Could also be a stuck regulating valve in the pump too....

Otherwise, what Fred said and plastigauge a couple of rod/main bearings while you have the pan off. If you can get the engine high enough it should be an "inframe" job. Not a fun way but it gets it done......

JD

Hay JD, Well things here have been crazy, the 00 XJ I had was killed by a falling limb as I was driving, so now I have a new project. About the plastic gage, I have heard of it, but never used it. Could you explain it? I have a problem witht he CJ idling too, I believe it to be a couple things, ie vacuum routing wrong, EGR valve not hooked up, it could be anything. Actually there are times were it will idle fine, then there are times it won't at all! (Carb) it seems to rev up fine, but who knows. THis is a "when I get the time" project. Baby due in June!!!!:grinyes:

Congrats on the new arrival in June

The plastigage is a method of determining the oil clearance in a split bearing like is used in a rod or main bearing.

A piece of soft wax material the diameter of a heavy thread is placed in the bearing. The cap is set in place and the bolts torqued to spec. removing the cap shows the spread out material. The width is compared to a scale on the plastigage package and directly reads the clearance.....

like this......http://www.fast351.com/enginerebuild/index4.htm


later

JD