Jamez

Hi...

I'm having some problems with my newbuilt engine...
Oil pressure is good when cold,but it drops off as it gets temp up...
I found that the checkvalve the oil to the head flows to was loose, but it didnt help much on the pressure.

I still have less than 14psi on idle...
This is using 10w-30 mineral oil (for brake-in)

I'm thinking oilpump since thats about the only part not changed this time. I just re-used my old one with 100k miles on it.
Does the pumps usually go bad?
They're supposed to have really tight clearance, aren't they ?

Any ideas is higly appreciated

Jamez.

urS4guy

Every engine that I've rebuilt has included a new oil pump regardless of mileage. That's using the same logic as changing out the water pump when doing the timing belt. That said, I doubt that the oil pump is causing the lack of oil pressure.

Hap, tryin to think like dahkine in Evahboost

AntiSocial

Did you have the cam/main caps honed?

Jamez

I dropped oilpan today...
Removed oilpump and it is BAD!
It made sound when rotating it, and pressure relief valve is stuck in half open posision,
and clearance sucks...

What amazes me is that I have been running this pump before with 300hp on the engine!

I had the crank polished and put in new bearings. They were "ok", but had some minor wear. Better safe than sorry this time

Jamez

did not have maincaps honed, but new bearings were put in.

Cam-caps were polished slightly... look my post below.
Oil pump was bad...

AntiSocial

oil pressure. Not to say that a new pump won't help your situation, but honing the caps keeps everything lubricated nice.

Jamez

and my bad pump was the reason