# MK2 Jetta Oil Pressure Idiot Light ?



## 98xj (May 17, 2011)

On my '87 Jetta GLI 8V 5speed the oil pressure idiot light/buzzer goes off completely randomly for a few seconds to a few minutes when I'm driving. It can happen rolling at 70+, cruising at 40, or sitting in traffic and everywhere in between. Oil level is dead on. It doesn't make a change in sound of the engine, no knocks/ticks like its actually got low oil pressure, idles and runs the same whether the lights on or off. Coolant temp is fine as is oil temp right around 180-200. I'm thinking new oil pressure switch and see what happens. Has this happened to anyone else? Thanks.


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## dogyouare (Aug 10, 2009)

replace the sensor.

take the oil pan off and clean pickup tube. if it still blinks might be the cluster or oilpump/bearing bad. u can put high pressure oil pump


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## cuppie (May 4, 2005)

Replace _both_ pressure sensors - one on the filter mount, one on the head.
(Side note: I've had very bad luck with auto parts store sensors leaking (and, therefore, also firing off erroneous warnings) on these things. Get good ones - either from the dealer, GAP, Parts4VWs, AutohausAZ, or Mk1Autohaus.)

Proper weight oil for the weather?
What brand filter? Many here have had issues with off-brand, budget, oil-change-place, or even Fram filters (honestly, the PH2870A 'fits' a lot more than it should) filters. 
Try a more 'proper' filter (Mann, Mahle, or Bosch), too. 

Still have issues? _Then_ dive into the pump.


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## 98xj (May 17, 2011)

I got the in head sensor today from worldpac and its a German one, going to swap it tonight and when i do im going to screw my mechanical oil psi gauge in and take it for a spin to see how the pressure really is, if good on psi and the head sensor doesnt fix ill get the oil filter one tomorrow. I'm running an stp filter(middle of the line) never fram crap and 10w30 conventional in 60-90 degree GA summers. If the sensors dont fix ill check the pickup. Thanks.


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## 98xj (May 17, 2011)

Just checked the psi and swapped the sensor. Light/buzzer still comes on just as random. Oil psi was high I thought when cold about 60 idle 90~3500 rpm, then at operating temp 25 idle 50~3500 rmp steady. Going to get the other sensor above the filter tomorrow and replace it see if that changes anything.


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## MK2-16vT (Aug 1, 2004)

silly answer but try 15w40 oil. it seems to make that light shut up! worked for my mk2 and my buddys mk3 aba


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## Seax_Smith (Jun 1, 2007)

cuppie said:


> Replace _both_ pressure sensors - one on the filter mount, one on the head.
> (Side note: I've had very bad luck with auto parts store sensors leaking (and, therefore, also firing off erroneous warnings) on these things. Get good ones - either from the dealer, GAP, Parts4VWs, AutohausAZ, or Mk1Autohaus.)
> 
> Proper weight oil for the weather?
> ...


*2X, 3X and 4X on this*

Get two of each sensor and keep the extras in a little box in the spare well. you will need them eventually. Also those sensors can sudenly do the arterial squirt thing and drain the engine of oil in a matter of minutes, so spares in the car with a deep well socket to change them is a very good idea.


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## Seax_Smith (Jun 1, 2007)

98xj said:


> I got the in head sensor today from worldpac and its a German one, going to swap it tonight and when i do im going to screw my mechanical oil psi gauge in and take it for a spin to see how the pressure really is, if good on psi and the head sensor doesnt fix ill get the oil filter one tomorrow. I'm running an stp filter(middle of the line) never fram crap and 10w30 conventional in 60-90 degree GA summers. If the sensors dont fix ill check the pickup. Thanks.


60*-90* F calls for something heavier than 10w/30. 10W/40 at minimum. 15w/40 is a good choice too. Common issue with MArk II's is the oil pressure switches combined with worn bearings and lifters which most poeple opt to deal with by running 20w/50 (which is on the chart in the bentley). NEEDING thick oil to shout up the engine is one of the first signs of an engine getting worn internally. Consult the oil selection chart in your bently, and remeber that "stuck in traffic" can be 25* F or more than the thremometer indicates.

90* + full sun on black top stuck in 0-10 mph traffic can have your engine sitting in a 120*F environment.


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## 98xj (May 17, 2011)

Thanks for the replies, replacing both sensors solved the issue, I still plan on pulling the pan to check the pickup as a PO still could've gone nuts with silicone and gotten some on the pickup or something. I'll probably stick with 10w30/40 its never failed in my area on any of my other cars.


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## Seax_Smith (Jun 1, 2007)

10/30 winter and 10/40 winters works. If your lifters are not worn, then you won't get the tick that most poeple cover up with 20/50. 90 is just too hot for 10/30.


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