Josh B

I am so frustrated. Just spent a couple hours searching the archives and can't find an answer.

I am having oil pressure issues with my 87 turbo with 139k running 20W50 dino oil.

I first noticed the problem when I was driving along at highway speeds and accelerating. The oil pressure would go down - a couple times to 2 bar and the ! light would flicker. When I let off the throttle pressure would come back up to 3 or 4 bar but still not the normal strong 4 to 5 at 3 to 4K RPM.

I changed the oil and oil filter and swapped out the pressure sender for a known good used one. Same issues. At startup and on easy driving the car seems to be fine - 5 bar at first until is warms up and then down to 2.5 or 3 bar at idle. If I got on the car and drove it hard then I would see the guage going down while RPMs were going up.

Two days ago I swapped in another 1 piece OPRV. I thought that had fixed the issue as yesterday I drove the car hard and she seemed fine.

Today however on the way into work on the highway I was at higher RPMs and looked down to see the guage way down at 1 bar or lower and the ! light was on and the warning light at the bottom of the guage. I shut the car off and checked the oil level - still full and the oil was still nice and new. Tried to start her again - still low pressure - 1 bar or so. Shut the car off and let her sit another 2 or three minutes. Started the car again and it was back to mostly normal. Drove the last couple miles into work with ok oil pressure - 3 to 4 bar at speed - idling at 2 bar.

I need to double check the torque on the crank but aside from that I am really at a loss.

Chads996

Sounds like the "crack in the oil inlet pipe" problem. That would produce this scenario.

Time to crack open the bottom end.

Thread jack - Do you still have those control arms?

C.

krystar

yup. sounds like symptom i had with cracked oil pickup.

if yer still unconvinced u have a cracked pickup, u can get a borescope with a light and go in thru the oil drain hole and look at it.

my pickup tube
https://rennlist.com/forums/924-931-944-951-968-forum/458038-well-there-s-your-problem.html

marky522

Could be a wiring issue to from the sender to the cluster also. I would verify with a mechanical gauge.

Mark

Josh B

This is what I am fearing. Holding out a glimmer of hope that the reason it is failing at higher RPMs is that the crank bolt isn't at full torque though and slips with more stress on it......

Just sold the arms today to a fellow up in PA for $1625.

wi54545

Maybe still some debris in the OPRV sleeve? Jamming it open.

potent951turbo

Josh, are you still going to try switching out your gears?

Josh B

Going to do that this weekend. Might go ahead and order rod bearings/oil pickup tube/oil pan seal though. If I don't use it on this engine I can use it on that other block I am hoping to one day build up....

MM951

FWIW, I had a similar problem on my old 85 N/A and it was the OPRV. I know you replaced it but figured I would just throw it out there..

Kburke

check the oil pressure sender unit first before doing anything remember KISS keep it simple stupid

Marcquito

Check that inlet pipe! There may also be junk clogging the screen. I say to go ahead and open it up and change the bearings and put a new pipe in. Wouldn't hurt to do that. You should see your pressure go up afterward.

Josh B

Well - changed out the gears and put 150lbs torque on the crank. Went out and drove around - got on the car pretty hard. After about 10 minutes of that I observed the oil pressure stay at around 3 bar on a hard pull. Brad(ilikemy944) was riding with me and we both are thinking it must be some sort of piece of trash that clogs the intake when it is sucking hard at higher RPMs.

I guess I'll be ordering a oil pan gasket, oil pickup and oil pickup seal today. Probably will see about getting another factory baffle in case mine is cracked up.... Not looking forward to this job. Hoping I can knock it out this weekend after Turkey day...

Lorax

Yikes man, I sure hope your car is problem free soon. Don't let it frustrate you! You will get her running right..

ilikemy944

I have found 2 similar issues out on the web, Audi/BMW forums.
Gunk in the oil pan was the issue for both.

Josh B

Thanks Brad - hope that wasn't too hair raising of a test drive....