chocolateman12

Recently on my 1986 944 NA, I have been having low oil pressure on startup, to which the oil pressure kicks in after 15 seconds of running. To try and fix this, I took out the OPRV and cleaned it out (I did find gunk in there) and put it back in. Now while cranking, I am not getting any oil pressure at all, despite how many times I crank it. I've tried:
Priming the oil pump by pouring oil down the OFH center hole and the perimeter hole
Filling the oil filter before installing
Feeling around in OPRV housing for any gunk or scoring
Cranking the car without OPRV in (no oil comes out)
Checked that the crank bolt is torqued to 155 ft/lbs

The only thing I haven't tried is the compressed air in dipstick method. Could this be a cracked oil pickup tube? Any suggestions will be helpful.

931guru

Has any work been done to the car recently? Water pump? Front engine reseal, etc?

If not, I would guess at cracked oil pickup tube or compromised seal.

walfreyydo

Sounds like youve looked at everything that comes to mind. Cracked pickup tube is a good thought. I think the behavior would mimic a straw that has a crack in it, meaning you have to suck very hard to drink through and certainly causes a delay before you are able to get he beverage up the straw... sort of like the behavior you are describing.

Will require dropping the subframe and oil pan, and while you are in there consider doing engine mounts (I used the cheap ones and theyve been fine, but others have different opinions), oil pan gasket, and rod bearings. Youll also have a good opportunity at that time to do the lower balance shaft housing seal, as well as the rear seal, if they are leaking (but a pain to do because you have to remove whole front seal/housing which means removal of the pulley and balance shaft belt, although you will never have a better opportunity to do this as well). The pan gasket is a pain too but not bad if you line up the gasket on the pan and use the bolts to hold it in place while you carefully lift the pan into place and get a few bolts started.

Another thing to check would be the oil pump seal to the block, which isnt a gasket but Loctite 574. If this needed to be replaced I think youd see a pretty major oil leak though.

chocolateman12

Yeah I figured, It's been a long 170,000 miles. Thank you for the help!

Jfrahm

Did it ever have issues with the balance shaft system?

harveyf

Just to positively rule out the gauge and the sending unit, remove the oil filter and crank the car. The car may start but regardless, oil should come out of the oil filter housing pretty vigorously within 5 seconds. If it does come out, you will have a mess to clean up but you have ruled out the cracked pickup tube. It is best to have someone in the car doing the starting duties while you watch the filter housing.

Dr. 914

make sure that the main crank nut and washer are centered on the oil pump drive ring and tight

chocolateman12

When I got the car, it wasn't running and was missing the balance shaft belt (it was ripped in half). So assuming it was driven like that before, it might have taken years off of the pickup tube's life. No oil comes out of the oil filter housing when cranking and/or even starting the car.

walfreyydo

Thats really good info actually and more evidence pointing to a possible cracked pickup tube.

weberlukas74

Yeah, I agree. If the car has a history of a missing balance shaft belt, driving it like that could have messed up the oil pickup tube. But I’d also check the oil pump itself. If it’s worn or not properly seated, it could be causing a lack of oil pressure. And make sure there aren't any blockages in the oil passages.