ROG100

Hi Guys be patient, Robert is at work and I know he will be posting as soon as he gets home.

ROG100

to recap,
Put a new seal on the snorkel
Pressure tested the snorkel no leaks
Put a drill on the pump and spun it fast - nothing
new oil pump seals
new woodruf key on oil pump shaft
added plenty of STP into the block and the pump
replaced TB and rotated the engine for tension check
started but no pressure
oil filter off and no oil flowing
oil filter full of oil and once engine is cranked some of the oil disapears
added an oil line with a connection at where the sender connects
pumped at least 2 quarts of oil in using a pump.
started the engine - instant oil pressure - ran for about 45seconds and the oil pressure reduced until the red light came on

soupcan

I would loosen the oil pan bolts, drop the oil pan 10mm or so and then prime with drill. If nothing then I would think it's time to take the pan off and get another look inside. A friend years ago got in a hurry replacing rod bearings on a SB chevy circle track car and left a shop rag in the pan, anything is possible. Hope he finds the problem.

shaaark89

roger,
did he actually pull the oil pump out and check the innards?

Fabio421

I'm still voting for oil pickup being too close to the pan. I've seen it cause this problem before in othet engines.

Roger, wher in FL is this fellow. Maybe we can get someone over to help him.

ROG100

Roberts in the Orlando area and will post in a few.
He is worried about being thrown to the Lions so be nice 8>)

6mil928

Come on that never happens here

Robert 81

Hi guys
Im robert with the troublesome 81 928 .
1st of all thank you all for the comradery.928 guys really stick together.I had no idea!
I am usually by myself on most projects and have no one to turn to.
As of the last thing done on the 928 was summed up by roger tyson.As far as leaving any rags in the pan I am 99.9% sure on that.I did inspect the pump thoroughly and am now leaning towards a suction forming on the rubber boot on the pick up tube on the snorkel against the black baffle on the bottom of the pan.When the engine was primed today as described by roger the enine did run for a minute with oil psi.but slowly dissapated I think as the oil ran out of the pump and could not pickup oil from the pan.I plan on pulling the oil pan tommorrow and inspecting again.Any ideas on what to really scrutinze and if i find nothing wrong where do I go from here?
robert

ROG100

Hi Robert,
Welcome to Rennlist - you are now party to the greatest bunch of 928 boffins known to man.
Make sure you post your findings from tomorrow and good luck.
Roger

Schocki

Robert,

welcome to Rennlist. I'm pretty sure they will find the problem in this forum.

Make sure that the snorkel does not seal against the oil pan. Do you know somebody with a borescope? Would be interesting to see through the removed oil plug into the pan.
Very handy tool in the Porsche world...

docmirror

Did you call me a,,,,,,, boffin?

No soup for you!

This is sounding like a leak in the oil pump housing area. Also look very carefully at the flange where the pickup tube bolts to the bottom of the block/cradle. Look for cracks in the pickup tube all along it's length, look up into the block area for obstructions or areas where air could get in.

When you reseat the pickup tube, try to find a way to pressurize the tube gently with air, and squirt some mild soap around the tube, and seal at the top. If you see bubbles anywhere you have an air leak.

ROG100

Robert is taking off the oil pan and we are going to fit the later snorkel while he is in there.
We will update once he has some news.

Angel84-928

Robert,
Welcome to Rennlist. I'm in Saint Cloud and although I might not be able to contribute with knowledge, I may be able to contribute by lending a hand and giving you a fresh set of eyes to look at the problem.
I'm working on R&R'ing my motor mounts so I'm going to replace the pan gasket like you. Well, maybe not like you.

At your disposal. PM me.

BC

The plasticy-rubber bottom of the oil pickup is "inadvertently adjustable" when its put back on. Its height could be too low to create pressure.

ALSO - very important - you have to turn that oil pump cog PRETTY fast to get oil pressure up.

killav

Maybe the oil pump itself is the culprit. Is it possible that the oil pump shaft has sheared causing the gears on the inside of the pump housing not to turn?