Low oil pressure

what were u using. i use 20/50 in mine during the summer but then i also unplugged the flashing light 4 years ago too.

mike

85 cabriolet

As I said, SAE 40.

Hey smartass, I said what were you using not what did you put in it.

as you said "I tried using a thicker oil (SAE 40), but it made no difference. "

If you are going to do the oil pump then we use to put the G60 Corrado pump in them. It has bigger flow which helps a lot. But sounds like the mains and rod bearings are also needed.

Is that a straight fit? and how long to swap that part out? any idea on price for that?

thanks mike

Thanks for your comments. As to needing mains and rod bearings, I hope that is not the case. I'll post the results of my new oil pump installation soon. I already purchased the pump, a German OEM.

Isn't there a later pump that's a straight bolt in that has even higher volume? I think it's for a 2.0 16V or maybe the newer 2.0 8V... anyway I remember it being discussed on the Corrado list, I think you have to have the shaft necked down for clearance for something but it's much cheaper than the Corrado pump and better.

nate

Woodchuck wrote:

Follow-up: The replacement oil pump German part number is 027115105.

My new pump is installed. I used 10W40 oil.

So far, so good. No longer getting a blinking oil warning light, but I will not feel completely confident about the repair until I have driven it for a couple of weeks. Here is how my oil pressure gage read, warm engine, transmission in neutral, various RPMs:

Idle, 950 RPM, 0.9 Bar

1000 RPM, 1.0 Bar 1500 RPM, 1.1 Bar 2000 RPM, 1.5 Bar 2500 RPM, 1.9 Bar 3000 RPM, 2.2 Bar 3500 RPM, 2.4 Bar 4000 RPM, 2.5 Bar

Engine cold, 2000 RPM, Bar > 4

If it stays out then you are lucky because the min oil PSI spec is 2bar @

2000RPM.

Well, unfortunately it didn't. I took it for a longer drive this evening, and the oil pressure warning light began to flash (after the engine got good and warm) every time the engine RPM slowed down at traffic stops (pressure was about 0.5 bar). The only thing I can think of right now (other than worn bearings) is that maybe the two old pressure sensors that screw into the engine and cam area are not reading the pressure accurately enough. I had purchased new sensors, but the guy who installed the new pump did not put them in because he said one was the wrong type and the distributor hardware was in the way of the other one - which would have led to a re-timing job if the distributor had been rotated to get it out of the way.

Sigh - more work!

I am not nuts about those OP readings, rule of thumb says 20 PSI at 2K rpm, you are just on the border at 2K RPM, you should really have more pressure at higher RPM, 2.5 bar is only 35ish PSI, it should really be higher than that.

nate

Papa wrote:

Yes, that is very true.

You apparently did not see my last post to this thread - in which I mentioned that the oil pressure warning light is still flashing (with the new oil pump installed). Anyway, all I am certain of at the moment is that the problem is not the oil pump. The oil pressure readings on my gage stayed pretty much the same after the new pump was installed as it read with the old pump. Hopefully the problem is due to inaccurate readings from my oil pressure sensors. If not, then maybe my head gasket is incorrect and is blocking some of the oil passageways. Worse yet, it might be bad bearings. At any rate, my next step is to have the oil pressure accurately measured with a professional oil pressure gage that service departments use. I'll post the result.

I took my car in for an oil pressure check today. The true oil pressure is much higher than the car gage and idiot light indicate. Here are the results from the service department's own oil pressure tester (engine warmed up, transmission in neutral):

Idle speed (around 1000 RPM): 18 PSI, 1.24 BAR

1500 RPM: 28 PSI, 1.93 BAR 2000 RPM: 40 PSI, 2.76 BAR 2500 RPM: 56 PSI, 3.86 BAR 3000 RPM: 66 PSI, 4.55 BAR 3500 RPM: 75 PSI, 5.17 BAR 4000 RPM: 75 PSI, 5.17 BAR

Nevertheless, I believe that the main bearings may be worn because they are audible.

I had the same problem with the light and buzzer on my 89 cab with 125k miles. Replaced the sensor on top of the oil filter flange and the problem permanently went away. $5 (i think) from germanautoparts.com - great company with great service.

Dave

Papa wrote:

Not to add fuel to the fire here, but have you tried adding the correct weight oil to see if maybe the problem goes away. 10W40 is inappropriate in most North American climates. The correct weight is 15W50 or 20W50 pretty much year round in most of North America. 15W50 (ala Mobil 1) is probably the best option for year round performance. Check your owner's manual or a Bentley.

I took my car in for an oil pressure check today. The true oil pressure is much higher than the car gage and idiot light indicate. Here are the results from the service department's own oil pressure tester (engine warmed up, transmission in neutral):

Idle speed (around 1000 RPM): 18 PSI, 1.24 BAR

1500 RPM: 28 PSI, 1.93 BAR 2000 RPM: 40 PSI, 2.76 BAR 2500 RPM: 56 PSI, 3.86 BAR 3000 RPM: 66 PSI, 4.55 BAR 3500 RPM: 75 PSI, 5.17 BAR 4000 RPM: 75 PSI, 5.17 BAR

Nevertheless, I believe that the main bearings may be worn because they are audible.