Mechanics

OIL PRESSURE PROBLEM (TOUGH ONE)

2002 Ford Focus

Engine Mechanical problem
2002 Ford Focus 4 cyl Two Wheel Drive Manual 500 miles

I have a 1959 Austin Healey Sprite, running a 2002 Ford Focus Zetec DOHC engine. The engine is completely rebuilt, new head, cams, new rods, pistons, bearings, oil pump, balanced etc. It currently has aprrox. 500 miles. When the engine was first started it was run in for 30 minutes then the oil and filter were changed. At approx. 500 miles the Oil and filter were changed again. 5-20w per manufacturers recomendation.

I was driving the car in 80 degree weather, engine temperature was approx 95c, and the oil pressure dropped from the normal 60 psi to 10 while driving 2000-3000 rpm. The car has a mechaincal gauge and an idiot light (not sure what pressure it comes on at).

I stopped and checked everything it semed to be normal. I opened the oil fill cap and oil was splashing like normal. So I decided to nurse the car home.

As I slowly accelerated the gauge would climb to about 35 PSI at 2500 RPM but then start going back down at about 2800 rpm to around 10 psi at 3500 rpm.

When the car is first started cold the oil pressure goes up to about 70 psi. At 1000 rpm idle when engine is bleow 80c the pressrue is over 25 psi.

Any thoughts, sticking relief valve? Bad oil pump?

Thanks
Rod
Avatar
Rod H
May 20, 2010.



Hi there,

Thank you for the donation,

My first thoughts are a sticky relief valve, I would start checking here.

Mark (mhpautos)

Mhpautos
May 20, 2010.