Need help analyzing oil pressure after top end rebuild
 

Hi

Having just picked up my 78 930, driving it home I see that the oil pressure is lower than before the rebuild. It used to hold pressure just shy of the standard I find when I search here on pp, at about 4000rpms it used to be 3-3.5 bar in Alabama summer heat.. Idling at 950 at just shy of 1 bar, maybe 0.7bar.

Now the oil pressure warm is about 2.5bar probably less. At 4k rpm. This is fresh out of the shop.

I haven't really had a chance to drive it much, since it started out blowing out one of the plugs from the smog delete on my first drive after picking it up. I logged fifteen minutes so far, just trying to adjust the AFRs since it was running way rich.

Further more, When I came home I realized the rear of the car was sprayed in oil. The car has got a new paint job and was clean when I picked it up.

When I parked the car in the garage, there was a significant leak in the area of the right side chain tensioner cover towards the centre of the car. The leak was clearly pressure induced. Since it was quite bad right after shutting the engine off. Now it is just an occasional drop.

My question is can this be linked together; the low oil pressure and the leak.

I just want to be able to understand this rather unfortunate situation after an expensive rebuild, and be able to contribute to solve this.

Thanks

Sorry to hear about your woes. Check out Schnele's "Resurrection" thread for some unfortunate seals that were out of spec and caused low oil pressure. TurboKraft stood behind the work but Most wouldnt. I hope it's not your issue too.

Yeah I hope Lincoln's story turns out good, in fact I am certain it will.

Mine was "just"a top end job. Wasn't the problem for Lincoln in the case and pump?

If you have a significant leak under pressure with the engine running, it will effect your overall pressure on the gage.
You need to fix the leaks first anyway, and then see if that raises the pressure back up. Are you running a lighter weight break in oil, as this might lower the normal pressure as well.

Fred

If it is leaking severely at the hose fitting for the chain tensioner near the oil pressure sender it may explain the pressure reading problem. Or the sender isn't screwed in or is leaking.

Thanks for the feedback guys.

About the leak. I don't think the leak is directly propertional to the low oil pressure situation

I was thinking, maybe if there is some thing in that area of the engine that could be clogged and cause a leak, and an poor flow with resulting low oil pressure indication.

This is just me guessing based on my very preliminary observations.

Once I can drive it again, I'll dig into it more.

I haven't been able to put my finger on one single spot where it was leaking. Now that I kind of know what I am looking for maybe when I crank it up again, I'll find it.