BCN

Would appreciate the collective wisdom of the group on very low oil pressure at cold start-up.

If the pick up tube is cracked can oil pressure build up over time?

At cold it took 42 seconds to peg at 5 bar. Engine is a little rough until full pressure but lifters immediately quiet down so there is some pressure.

2 hours later, still immediate oil pressure.

Any thoughts?

kevin12973

I'm no expert but I think your OPRV is hanging up a little. When warmed up it moves free. Cold it hangs up, just what I was going through. Just my opinion

kev951

have you verified actual oil pressure on startup with a mechanical guage in the oil pressure sender port yet?

BCN

Update:

I now have oil pressure at cold again and everything seems back to normal; took it on the freeway this evening.

The only thing I did was change the oil and filter.

First 3 times cold after oil change, less than 10 seconds running no oil pressure, finally decided to let go for a minute max and got 5 bar. When the pressure came up it was instant to 5 bar like something was unplugged, it did not gradually build.

However, I did overfill by 1 qt of oil.

So, I guess either the OPRV was stuck and is now unstuck or the pick-up tube is cracked very low and the extra qt of oil covered it, or it is intermittent and will return.

FRporscheman

Sounds like your dash oil pressure gauge isn't working right. Try the procedure on Clark's Garage to test your oil pressure sender.

A mechanical gauge would answer a lot of questions.

BCN

Thanks, pressure via mechanical gauge will be checked over the wknd.

BCN

UPDATE:

Oil pressure tested with manual gauge, matched sender. Back to normal now and idling very smooth. OPRV showed no damage on bore.

Currently running M1 15W50 after 50/50 diesel engine flush at idle for 30 minutes.

Strained oil after flush, did not notice any sludge or debris, oil had less than 30 miles on it. Diesel was added to 20W50 oil.

FRporscheman

You ran a 50/50 mix of 20w-50 oil and Diesel fuel in your motor? Never heard of that one.

I still think it's possible your no pressure -> sudden pressure situation could be just a bad sender, intermittent. I guess just keep an eye on it and see if it keeps behaving.

BCN

Yes, old school Austrian mechanic (farmer) recommended the diesel as it is actually a very light oil with detergent.

Can't guarantee it worked, but seems much better, for now.

FRporscheman

Well, I know diesels like to get some ATF in the fuel now and then to quiet down the injectors, so I guess there's a power steering pump out there that uses sae30 to complete this trifecta. (j/k)