oil pressure.

The details:

1982 VW Rabbit Diesel, American. 432k miles.

Oil light keeps coming on when the engine is hot.

So I broke down ,and pulled the top oil pressure sensor ( the one in the side of the head) and installed a pressure gauge.

This is where it gets wierd.

When cold, the car produces about 80 lbs of pressure at idle. Put it in gear and it blows past 120lbs.

When hot, it sets at about 30 lbs at idle, and goes to 80 lbs under load.

If it's _Really_ hot, it drops down to about 25-28 lbs and the oil light flickers.

Is this normal?

Reply to
Matthew House
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I would say that is normal for a car with that many miles and wear (possible bearings) and a stuck pressure relive valve.

Reply to
Joseph Meehan

First of all, if that's 25-28lbs at hot idle, your light shouldn't be coming on... are you still getting say 50-60 lbs at speed? If so there's nothing to worry about. and yes, I have seen cold VW engines show some amazing OP pressures, that's why it's so important to use a good oil filter (i.e. not Fram) to avoid the dreaded Oil Slick of Death on a cold start :(

nate

Reply to
Nate Nagel

Ok, so where is it located and how do I replace it?

Reply to
Matthew House

Ahh but it is, but only flickering.

are you still getting say 50-60 lbs at speed?

usually more.

If so

huh. well lucky for me, the previous owner, who bought it new was religious, or perhaps fanatical about following service procedures. As a result, I have a motor with 432k on it that runs wonderfully.

Reply to
Matthew House

...

It requires engine disassembly. Frankly I would not worry about it. I might consider checking the pressure relive valve. Sorry I don't know where it is, or for sure it there is one, on a 1982 Rabbit Diesel. I had a Rabbit Diesel. I can't remember what year it was. It had 180,000+ on it when my Ex totaled it. Fortunately she was not hurt.

Reply to
Joseph Meehan

After thinking about it, I guess you were asking about the valve not the bearings.

I should not try and think after I get back from a run. Got to allow time for the blood to start going back to feeding the few little grey cells that I have.

Reply to
Joseph Meehan

If you get oil warning lamp, first pressure must be checked at rear of head. Purchase a mechanical pressure gauge at your local autoparts/kmart/walmart wherever. The 1/8" brass male pipe thread adaptor can be chased with a 10x1 die and wrapped with teflon tape. The gauge and hose can be run through Left rear hood corner and around door pillar without crimping. Drive car hard until engine is HOT ie higher rpms--third gear at 50mph type driving. Minimum spec is 1.8bar (one bar aprox 14psi) or about 25psi @ 2200 rpm. If lower pressure experienced, turn around for home/garage. If pressure is still up there after 1/2 hour hard drive, allow to idle for 1/2 hour. Minimum spec @ idle is .3 bar or 4.5psi and if pressure drops lower stop engine.

The factory oil pump in 1.8ltr motors has 26-28-30mm gears and many produce insufficient volume/pressure after X miles. X varies, we can't curse any one pump manufacturer and have even sent LASO and FEBI/Bilstein of Germany and Shadek of Mexico, OE suppliers several samples and all claim NO PROBLEM FOUND. The 36mm replacement used as OEM on the 2.0 ltr motors, starting with Audi 80/90 and all the new Golf III/Jetta III often eliminate this problem on older motors as per European Car magazine article "Inside the 2.0" of 2/95. We stock these pumps and they are available through your local dealer as

027 115 105E retailing for $185.--a lot cheaper than a new car or motor.

If pressures check out ok, defective sensorscan be identified. Drive vehicle with head sensor unplugged and insulated from ground. If warning is eliminated, replace sensor 056 919 081C. If warning continues, reconnect sensor at head and disconnect at filter flange. GROUND this wire and drive vehicle and if warning dissappears, replace 068 919 081E is stock 1.8bar on gas motors and 068 919 081 is stock 1.3bar on diesels. Many circumvent pump replacement by switching to this (lower) high pressure sensor. Doing so will only accelerate undesired engine wear!

If warning continues after sensor check, problem is defective warning relay on USA Rabbit, Audi 4000/80/90. Part number is something like 813 919 082

-Oildruck Stompdamper (sp) and if unplugged and discarded, system returns to the old standby....if the warning goes off--light flashes--STOP! The early warning system is gone, don't wait for the no longer present buzzer.

On Golf/Jetta/Quantum, others, the warning relay is on circuit b behind speedometer inside instrument cluster. Remove cluster and carefully remove clips which retain plug for cluster harness. Remove two upper bulbs by twisting 90 degrees and plan on changing these before reassembly--pulling the cluster for a blown bulb is a bummer. Unsrew all eight screws from cluster and instuments. Wiggle speedo as lifted off vinyl circuit board to unplug buzzer connector. Depress tabs and remove circuit board behind speedo and

Joel Osserman, proprietor SelectEurocars.com -Top 10 Buyer VW Off Lease USA '85-2001

0685 Waterloo-Geneva Rd. Waterloo, NY 13165 (315)-789-9368 phone (315)-789-9018 fax Always a choice of, 1995+ off-lease VW/Audi See us @
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