Low Oil Pressure Warning 16 V Mk 2 GTI

[healy1]

Hi

This is an intermittent problem . Both sensors have been renewed . Light and buzzer sound when it does activate - engine has been checked by removing one of the sensors and attaching temporary oil pressure gauge and pressure is fine .
No apparent reason and light/buzzer will go out after say 1 to 5 seconds - may then go days operating fine .
Oil is 15  40 Semi synthetic and oil filter is new . One site I checked in Germany talked of this issue and tracked down to damaged rear crankshaft seal but I struggle to see how that could cause the problem as engine obviously has pressure .
In fact the clutch was replaced as soon as I bought the rear oil seal may be the problem .
Next step would seem to be to relace the buzzer ( perhaps )  Currently having to run with one of the two sensors disconnected as that started to sound off in a non intermittent way . This is frustrating - not good for anyones nerves - I am tempted to fit a permanent oil pressure gauge but would really like to solve the problem    140 ,000 miles
Any ideas please
Cheers
Martin

[robh]

I'm no auto electrician but, it couldn't be some dodgy wiring fault could it?  If the senders are good and you've checked them with an oil pressure gauge it has to be an electrical fault further along the line?

If I was you I would install an oil pressure gauge this weekend just for piece of mind, there not expensive and you already have the sender there to drive it.

[dubstar]

Few points:

A) is it the below 2000rpm sender or the above 2000rpm sender thats setting off your light?

B) did you replace the senders with the correct ones? (there are about 6 different types, all fit, but only the correct ones work properly.)

C) Is there an oil leak coming from the face between engine and gearbox? (this is where a rear main seal leak can be seen)

D) Is your engine full of crap?  A quick oil change (1000-2000km) may flush out the rubbish.

[GLIDN]

i thought this may help, seen this on the net and this is there solution.


I have a 1992 Jetta 1.8L with 5 speed transmission with 118,000 miles on it. I am having trouble with the oil pressure warning system. I have verified with a mechanical gauge that there is 20 psi at idle at the oil filter and the head. I have also installed a new oil pump, new pressure sensors, 20w50 oil and a Bosh oil filter. I still have an intermittent warning light and buzzer. The light and buzzer come on at idle most times and can be cleared temporarily by revving the engine. The oil light and buzzer will also go off for very short periods while driving the car. I have been suspecting an electrical connection but have not been able to pinpoint the problem. The VW dealer is suggesting changing the flex board on the back of the instrument cluster. Any suggestions would be most appreciated. thanks, m vossbergmichael vossberg 11/3/2001

Mike; Most of the 95-92 Golf and Jettas have a small circuit board in the instrument cluste called a "dynamic oil pressure control unit" .The book will tell you that minimally acceptable oil pressure is 2 Bar or 29 PSI at 2000 RPM. If you have that minimum then the problem is probably with your senders or gauges or the connections in between or the dopc unit.. This dynamic oil pressure control unit or dopc unit checks oil pressure at low RPM and at higher speeds. You can check that flexible circuit board visually and with great care and you might find a break. It might be nice to have a used known good unit that you could plug in as a tester. Then you need to isolate whether the problem is in the flex board or in the dopc which is a circuit shaped like the state of Florida or you just have bad connections somewhere. Sometimes just wiggling wires to see the gauges move is one of the best diagnostic tools there is.

or this one.


oil pressure Date: 4/9/03 anex.com I have a 90 volkswagen Jetta (gas)and have experienced my oil alarm ringing in. I had my mechanic change the switches but it still rings in. I ran with an oil pressure gauge in my front windshield to get an indication at what pressure the oil was running at. When it was connected to the lower( location on the engine block) switch the pressure ran between 20 and 25 psi. The alarm still rang in. When I ran it from the upper location the pressure ran lower ( about 18-20) psi. The alarm never rang in because I have to take the switch out to put in the pressure gauge. I am wondering from what I have told you if you have any recommendations for me. Thanks Clint.

Clint; Your Bentleys manual will tell you that minimum oil pressure for that car is 2 bar or 30 P.S.I. when the engine is revved up to 2,000 RPM. You don't have to be driving the car to run this test. Also if your oil pressure really is low you probably will be able to hear that the engine is noisier than usual. For some reason or other the oil pumps on these cars will suddenly go out on you. Probably the pressure relief valve in the pump is getting stuck in a partially open position. The oil pressure problem if you have one could also be the result of connecting rod and or main bearing wear or could be a secondary problem created by bad pump or visa versa. We always replace the pump with a new one and remove some or all of the connecting rod bearing caps to check for wear. If oil pressure is not below specs then the switches or possibly a circuit board in your dash instrument cluster called a "dynamic oil pressure control unit" shaped like a map of the state of Florida may have a bad connection or is defective.

I hope this helps

[hartster]

I've also got 16v 1.8 in a mk2. I had exact same problem immediately after its rebuild - at about 3000rpm under normal conditions the light / buzzer suddenly came on. i lifted the bonnet very very slowly expecting to see oil everywhere but level was fine, clean, running / idling smoothly, no rumbling grinding noises or anything. using regular 15w40 during run in and then will go to synthetic later.

i did 2 things: i put a genuine vw filter on, in place of aftermarket brand (criminal offence in the first place), and checked / cleaned with contact oil all the connections in the engine bay pertaining to oil pressure sensors. haven't had the problem since, which is great relief as i brick it big time when the light / buzzer comes on.

[orggti]

this is great ive got a customer whos got a 90 mk2 golf gli and she has exactly the same problem. ive replaced the senders and it made no difference. I think as all those people said if youve got a over 100,000km motor you just dont have enough oil pressure when it drops down to idle (this is the time her car does it) and if you have a car doing it at higher rpm then id pull your sump and have a good look at your oil pump and make sure the releif valve isnt stuck. also check your crank shaft end float as if the person has left there foot on the clutch at lights (or its really high ks) then i have had the crank wear right through the centre thrust bearing and wear a good 3-4mm out of the cap and crank shaft (in my old mk1 gls) filling the sump full of nice swarf which then blocked completely my relif valv and then the oil pressure went so high it blew everywhere out of the side of the oil filter. Of course it was the ONLY time id EVER got somebody else to do a oil change (got given a docket thing) for me so i blamed them!!!! and ended up getting into all sorts of trouble it was the worst feeling,(he threatened to punch my head in, I had to get mates to come with me to get my car back!!!to protect me of course i payed him i was only angry at him till it was found out what went wrong but he never got over it) bad enough to make me a mechanic now maybe not the best mechanic in the world or even qualifyed but i am a mechanic