thanks to everyone who replied earlier today,

i have oil pressure while cranking now.. which steadily climbs to just below 6 bar . Cause to be seriously alarmed?

points to note:

i used vaseline to fill the pickup pipe with oil before backing filling the filter/pump with oil through an accesible oilway

i had both the release valves out of the oil pump and they looked fine

the engine is filled to just below the max line with 15w30

engine is cold (cranking using starter only) and hasn't been run since I bought it 6 months ago.

worried when i start it next week its going to explode!!

http://www.youtube.com/watch?v=Gyy3OR0SDV8

[Edited on 16/1/10 by cd.thomson]

Eek!

I have a similar problem on my kit (2.2 renault engine), and as the oil warms, the pressure drops.
Ive got the sump off at the moment, so ill take advantage and remove the pressure relief valve and give it a clean / check.

Did you check yours? sounds like the pump is priming, but not passing oil through quick enough.

Mines was regularly running 80 psi at cold and when warm goes down to 40psi at idle. Normally always around 70 to 80 psi at revs and done 700 miles (engine is in the 100,000 plus really though.)

15W/30 I hope you mean 5W/30

quote:

---

Originally posted by snapper
15W/30 I hope you mean 5W/30

---

A back pressure of 85 psi (just under 6 bar)is quite normal for a stone cold engine.
The fact that the oil pressure climbs steadily to 6 bar while cranking is an indication that the back pressure is being achieved by cold viscous flow in the galleries rather than a blocked oilway or stuck valve which would tend to give a rapid pressure rise.

One other point is that oil pressure sensors (like the VDO ones) can have sizeable inaccuracies, so that a car pressure gauge should really only be used as a comparator rather than an absolute measure of pressure.

In our project here in Yemen we run over 300 generators with 1600 hp engines and the electrical pressures gauges are at best +/- 10%. Cold start pressure on these engines can be over 6 bar even at ambient temperatures of 40 deg C, but it would quickly drop to 3 or 4 bar

Check the recommended lubricant 15W/30 really isn't a good idea, I think you will find it should be either 10w/40 or 5w/30

6 bar isnt bad, my pinto used to run 120psi cold and 80 psi when hot on 10W60 fully synth with a high pressure pump.

I wouldnt worry

thanks for all the responses. I will check the recommended oil again BT

6 bar should be OK 8 bar wouldn't be risky.

Big danger with excessive oil pressure is from a cold start the oil fillter wil explode (actually top half seperates and gets fired off l ike a rocket) -- I have seen this a couple of times.