All,

Finished installing an oil pressure gauge in my son's 95 850 Turbo. Let me tell you, getting your hands in to remove the oil pressure and install the new one is a PITA, but it can be done. Anyway, I got a dual input sender so not only does the gauge work, but the factory oil pressure warning light remains functional as well.

Here is what I have noticed. When cold, the oil pressure remains close to 60 PSI from idle up to highway speed. As the oil warms up, the pressure slowly drops. After about 20 minutes of running (both city and freeway driving) the gauge reads about 35-40 PSI at 70 MPH, and about 22 PSI at idle. Seems fairly normal to me, but I would like to ask the experts.

Current oil in the car is 10W-30 with about 1100 miles on it.

Thanks for any input.....

Glenn

 

Hello Mr. Psaboic,

Greetings from Chicagoland.

My reply may not be accurate in regard to the specified oil pressure, as I do not have the correct oil pressure range in my manual (Haynes). Factory manual may have the spec, but you could probably ask at a local dealer or some experts on this board may be able to tell you.

You probably know this, but it is normal for the oil pressure to drop as it warms up (a reason I stay away from 5W-30). At highway driving, the pressure is higher than at idle since the oil pump produces more flow and have to fight higher engine output. At idle, the pump is producing less flow and the engine output is less, thus the less oil pressure.

10W-30 should be good, that's what I use (Valvoline synthetic blend). It is slightly more viscous than 5W-30, but I just let the engine idle for about 3 minutes after starting and then slowly drive away. The wider the gap between the SAE numbers, the thinner the oil.

1,100 miles on oil is nothing. 3,000-4,000 miles is good oil change interval (3,000 for turbo), 5,000 may be too stretched. Also, I recommend using factory oil filter (Mann/Volvo), as it has check valve in it.

Here's a reference:

http://www.fcpgroton.com/volvo850tuneup.htm

I wish I had an oil pressure gauge too, especially for turbo-charged engine.


JPN

 

Min 750 RPM 0.10 MPA
Max 4000 RPM 0.35 MPA
Reduction valve opens at 0.60 MPA
Max oil pressure 0.70 MPA

Sorry not good at the conversion.
That is out of my cheater book.