Low oil pressure and noise

B

brannigan

New Member
I'm looking for a little advice. My v8 has always been a bit tappety when warm but recently it is sounding very loud and my oil pressure is down to 5psi when idle. A colleague at work suggested that the top of the engine is starved of oil hence the noise. I think the oil pump may be the problem and could need repair/replacement. Any thoughts?

Thanks.
 
Have you checked the pressure with a known accurate master guage? The guage in the car isn't a precision instrument. Are you using 20/50 grade oil? The pressure should be 30-40psi @ 2400rpm HOT. There are upgrade kits for the pumps but their primary purpose is to raise the volume of oil pumped, not the pressure. The pump housing is in the timing cover, so pump replacement would involve changing the timing cover. Worn crank bearings will cause a loss of pressure, and if that's the case then replacing those will bump the pressure back up again.
 
I would say I believe the gauge given the noise. I'm using comma classic 20/50. It has been suggested that I swap the oil pressure release spring as that is a cheap part but if that doesn't work I guess the next thing is to take off the timing cover and take a look.
 
Wear eventually gets to old V8's so if your thinking about top end it is probably good to sort out the works.

But for a quick fix have a look at the rocker shafts, they wear out and wont help oil pressure, the relief spring is a good idea to.

Colin
 
I'm thinking about taking the engine out. The engine bay needs work, one of the exhaust manifolds needs replaced and the gear change is stiff at best. I have good power and no smoke so I think the bottom end is ok but the top is another story.
 
Blocked oil pickup strainer? Blocked oil filter? I would be looking at these first. If you had no problem with noise before and your oil pressure gauge was reading ok then its likely now that it is reading low that the gauge is doing its job ie you have an oil pressure problem.
It's easy to remove the sump and check the pick up and also the condition of the bearings.

Graeme
 
You must log in or register to reply here.
Back
Top