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Oil pressure light flashes when idling

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The oil pressure light goes on and off. Seems to shine when idling and then turn off when I accelerate

I have a 1981 diesel rabbit pickup. Recently the oil pressure light has been flashing on and off. It seems to light up when I idle and then go off again as soon as I accelerate. The first thing I checked was the oil dipstick. It was a bit little low so I added two quarts of new oil. This did not change anything. What's might cause this?

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little low and adding 2 quarts?
little low to me is 1/2 quart.

Bad sensor, bad filter, bad grounds, bad connection on the sender. it is the one on the side of the head.
improper sender on the head is another possibility.

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

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I guess 2 quarts is about 2l it's only about 1 between minimum and maximum running that low or that high on oil is not good… where is the level on the dipstick when cold?

1988 Mk1 Golf GTi Cabriolet 1.8cc DX, K-jet. Daily drive. 290,000 miles and counting
1978 Mk1 Scirocco GLS 1.6cc FR, Webber carb. Weekend toy.

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I overfilled it a bit. I think I probably added ~1/2 quart more than necessary. It was a bit below the low mark on the stick and I misjudged how much the gap represented.

My dipstick is hard to read because it's behind a couple hoses, so when I pull it out it tends to smear against the sides. In retrospect I was probably a half quart low and now I'm a half quart high.

Briano1234 Sounds like you're thinking it might be a false indicator. Is that theory consistent with the fact that it happens pretty predictably, only when it's idling and warm? I would think a loose sense or something would be more random.

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Not sure what type of oil pressure sensor you have on a diesel but on petrol cars they are cheap to buy, might be worth trying a new sensor and see if that helps?

1988 Mk1 Golf GTi Cabriolet 1.8cc DX, K-jet. Daily drive. 290,000 miles and counting
1978 Mk1 Scirocco GLS 1.6cc FR, Webber carb. Weekend toy.

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I can't remember the exact pressures, but I know if you don't use a diesel gauge off the head you will blow the innards out of a Gassers mech gauge.

The only time my light would glow was when it was about 1 qt low, and I could only see it at night at idle….
I did have to replace the sensor a few times over 350Kmiles (I think I replaced it twice) as they will leak oil and that can spew it out if not caught early….

IIRC the cold pressure (oil is cold is over 90psi.)

 

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?
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