I just replaced the head gaskets, oil pump seals and gaskets along with a new sending unit on my '86 EA81. The problem is after the engine reaches operating temperature the oil pressure drops to about 5lbs at idle and only about 25 at 3000 rpm. This was not a problem until after the new parts. Any of you guys have a suggestion? Thank you.

Mine used to do something similar to that. But when I would get going it would get to about 30-35 psi. At a red light it would drop to really low but as soon as I started going again the pressure would pick back up, the owner manual said this was normal. I suggest keeping an eye on your oil level has some have had issues with the oil gauge reading incorrectly.

I would caution against resealing EA81 oil pumps - by the time they need it they are generally totally worn out. Replace the pump and see where you are at. You did put the spring back in that controls the pressure right? Did you inspect and measure any of the tollerances in the pump? Most of them that I have torn down are badly scored from people not replaceing the oil filters soon enough and dirty oil bypassing the filter and eating the insides of the pump. I have thrown away probably half a dozen that were totally chewed.

 

GD

Edited August 11, 200916 yr by GeneralDisorder

I did not check the tolerances but the inside was not scored at all (i know this doesnt mean it may not bad though). Think I will just replace it and try that.