Help needed - Oil Pressure & Pinking on new Cosworth engine
 

Hi forum,

Its my first post and i hope you will be able to help me.

I am the owner of a 1990 190E 2.5-16v. Very recently i had the complete engine rebuilt, so thats new valves, pistons, seals, chain etc, etc.

Since the rebuild i get pinking or pinging under acceleration. Its like a metallic rattling noise. I have checked to see wether there is anything loose and there is not. I have taken it to a bosch center and they cannot find any faults. But it only started after the rebuild.

Also when the engine was rebuilt its first fill of oil was 15w 40. Then i changed it at 500 miles with 10w 40 (semi synth) then a further three times up until 2000 miles with mobil 1 0w 40 fully synth.

A month or so after the rebuild the oil pressure began to drop just under 3 bars. Now several months later its just over 2 bars. But goes to 3 upon acceleration.

Can anybody shed any light on what is going on and how i can resolve these issues?

Thanks

Korres

im under the impression that 0w 40 is fine if you have had a full rebuild?
im using 99 octane gas...
if they have planed the head, is it down to them to rectify?

Is the oil pressure just dropping at idle/low RPM's? If so, then thats normal as the engine warms up. When i've been on a long journey and my engine is at full operating temp, I get about 1 bar at idle, but this pegs 3 again as soon as i'm cruising again.
In a performance orientated engine like that, maybe a 5w 50 is a better choice if you have frequent cold starts. I run a 15w 50 in my Porsche, but I only use that in warm weather.