I just put a mechanical oil pressure gauge on the coupe last night because the stock gauge was doing 'odd' things (like dropping below 0 at idle.)

Here's what it's doing...

Cold:
40-45 psi Peak @ higher RPM's
20psi @ Idle

Hot:
20-25 psi peak @higher RPM's
15 psi @ 1000 rpm
10 psi @ idle


I'm assuming by this that the pump is ok and that the pressure is low due to heavily worn main bearings.

Given these pressure's, how bad off is it?
Do you think I can get by with just a set of main bearings? Or should I do main and rod bearings. I'd like to do as little as possible to this engine as the longterm plan involves the same little toy that Scott just got the other day.

 

if you are going to put mains in it, you'll have it apart anyway and for about another 30-40 dollars just put a new pump and rod bearings anyway should solve any problem.

 

dont forget your cam bearings

 

If your going to take the time to do mains you might as well do the rod bearings while your down there.

 

Remember to check your clearances.

 

I'll keep an eye on my pressure guage tomorrow and see how it's running to give you a comparison.

 

Definately do the main bearings. That oil pressure sounds familiar...much like my old 89 before it died.

 

Mine runs 50psi at idle and gets up to around 75 wot.

That's what the stock guage says, and I think it's correct.

 

How many miles you got on it?

 

125,000