Arty92

Hello everyone, one of my first posts here. Been a long time lurker just reading everything on this forum. Ran into a weird issue where my car has no oil pressure randomly and thought I would ask for some advice. Some details about the car: it is an 87 S with a completely stock 16 valve engine with about 92k miles on it. I have owned the car a few months and everything was running perfect before this last oil change. It was about time for an oil change so, I got myself a mahle oc142 oil filter and I thought I would try some of the synthetic VR1 20W50 to see how the car ran with synthetic oil since the engine has been pretty much resealed. Previous owner changed the clutch a few months back as well as rear main seal and about a year ago did a timing belt with a few front seals. So I changed the oil about 3 weeks ago from today with the full synthetic VR1 and I did not prime the oil filter. I started the car and everything was perfect. The oil filled into the oil filter there was 5 bar of pressure and all was well. Let it run for about 15 minutes because I did not have much time to drive the car after the oil change. The car sat for about a week and half since it is my second fun car. I then went to start the car to go for a drive and my odometer was reading 0 oil pressure. I only let the engine run for about 15 seconds and shut it off to prevent any damage. I checked the oil pressure sending unit and it is fine. To make sure it was not just the odometer lying to me I pulled the oil filter and cranked the car with the DME relay off so it won’t start to see if any oil shoots out of the oil filter housing and there was 0 oil shooting out. I tried to prime the oil pump by filling both holes with oil and turning the crank with a ratchet and a 24mm socket counter clockwise to try to prime the oil pump with no luck. The reason I am making this thread is to ask a few questions before jumping into the huge job of dropping the oil pan and potentially replacing the oil pump.

1.) someone told me that the synthetic VR1 might have caused the issue mixing with the remaining Dino oil that was not 100% flushed out of the engine. Is that something you guys have ran into and what did you do?

2.) I am going to check the torque on the crank pulley before doing anything drastic but is it worth my time to potentially replace the seals on the oprv or just replace the whole unit?

3.) is there anything else to check besides crank pulley and oprv that I might be missing? I guess I can also try to overfill the sump to rule out a cracked oil pickup tube but a part of me feels like why would that be an issue randomly if the car ran perfectly fine for 15 minutes a few weeks ago before I let it sit.

T&T Racing

Try reprising oil pump by pressurizing the oil pan sump. It takes two people. Block/seal the end of the AOS hose connected to the J boot. Use compressed air regulated to 15psig to pressurize the oil sump by inserting an air gun with rubber tip into the oil check level tube. One person operates the air gun while the other person engages the engine starter