LiMBO - Late Model Bus Organization, International

Technical forums => Vanagon concerns => Topic started by: Bill Patterson on June 11, 2007, 09:09:01 PM

Title: Flashing Oil Light
Post by: Bill Patterson on June 11, 2007, 09:09:01 PM
I have an '86 Westy GL with a 2.1 in it. The low idle light flickers almost constantly, unless I am accellerating. I have changed the sender a couple times, but it only stops flashing for a short while. Also, I do use 50 wt. oil. I don't seem to have any problems with the westy, it runs well, sounds okay, etc. A couple VW mechanics, in the Albany area, have told me not to worry about it, they tell me my van runs great. They have never suggested doing any engine work on it- I guess it's the "If it ain't broke, don't fix it" theory. I have driven it thousands of miles this way. Including trips from Albany, NY to Bar Harbor, Me. and to the Thousand Islands with no problems. Should I do anything or just ignore it? Any suggestions/advice would be greatly appreciated. Thanks- Bill
Post by: MrLiMBO on June 12, 2007, 10:02:43 AM
Just to clarify, it flickers at idle and goes away when you rev the engine?   Or does it come one while driving with the RPMS around 2000 and it goes off if you accellerate?  Did someone put a mechanical gauge on the engine to determine actual oil pressure? You could have several problems.  Your next answer will determine what it could be.
Post by: Bill Patterson on June 12, 2007, 06:08:52 PM
I can't really say if it does this when I am in neutral and then rev the engine. Maybe I have never noticed, cause I think it only happens when warmed up. But when I am driving and let off the accellerator, even at higher speeds,  the light will flicker even if the rpms are a little above 2000, it stops once I accellerate again. When stopped at a light it will continue to flicker. I never have had  a solid red light (I don't know if it does this). The engine still sounds fine and doesn't stumble or make any alarming noises.  The sender with the buzzer never goes off since I changed it a few years back. I did speak to a VW mechanic today about installing a oil pressure gauge today. I am not sure if I want to do this, cause it might make me even more crazy/paranoid when I drive it.
Title: Flashing Oil Light
Post by: beebrew on June 12, 2007, 10:01:01 PM
Hi Bill,

I have an 88 that did a similar thing only when hot from a long drive. When looking into it I heard fixes from using only German oil filters to changing the oil bypass plunger and spring. As my oil sender was leaking, I replaced it using a factory original to no avail. I tried 20-50 wt synthetic blend oil. It was a bit better. The fix for me was using 20-50 full synthetic oil. It apparently maintains sufficient viscosity when hot to keep the pressure up to the minimum needed for the sensor. I suspect the issue is a combination of the main bearings and the oil pump  showing some wear. If the engine sounds good, I suspect your mechanic is correct in that is is OK. This is a common problem for high miles on this engine. Most any engine with a gauge will show dramatically lower pressure at idle.

Good luck,

Title: Dynamic oil pressure system
Post by: MrLiMBO on June 13, 2007, 01:47:44 PM
From 86 VW put an oil pressure system simliar to what was used in the Rabbit, Golf and Jetta.  They called it the dynamic oil pressure warning system.  

The engine has two sensors on it.  One between number 3 + 4 cylinders pushrods and the other is just behind the crank pulley.  The sensor near the push rods is your standard sensor. It creates a ground and turns on the light when the pressure drops. The other works just the opposite. It creates a ground when the pressure is up.    A lot of people don't realize this and when they replace the rear sensor.  

There is a control unit behind the speedo in the dash and it gets a signal from both sensors as well as the engine RPM's. The control unit looks at the lower sensor when the engine is below 2000 RPMS. Then it looks to the rear sensor above 2000 RPMS.  

Other than an incorrect sensor, the other problem I've seen with this system is wire fatique.  Both sensor wires come up and connect to a two wire plug near the thermostat.  Many times, the wires are zip tied to the hose near the thermostat, so they vibrate with the engine.  

If it were my van, I'd check that connection first.  Even if they look attached, they sometimes start to break inside the coating.  Give them a good tug.  Don't be afraid.  Personally, I would strip the wires back and install new connectors and hook them back up.  Just remember the wire that comes from underneath the engine gets hooked up to the blue wire.   (I can't remeber the color of the other wire).

(Shameless plug) Its cheap enough that I would put two new sensors from your Local Friendly VW dealer.  The blue sensor, which goes under the engine part number is: 028-919-081-D.  List price: 19.88 (WOW, they used to be 6 bucks. I guess they went up)   There are a couple of choices for sensors near the rear pully.  You could use: 068-919-081-A  (color Grey) (7.92 list)  That one has a pressure of .9 bar which will be less sensitive to pressure changes.  Or you could use: 056-919-081-E (Color white)(7.92 list) That one has a pressure of 1.8 bar which means it be more sensitive to pressure changes.

It could be a control unit.  Anything is possible. My suggestion: Check the wires where the two sensors come together.  Good luck.