Oil Pressure light flashes

Hi guys

As I come to a standstill whilst driving or slow down the oil pressure light keeps flashing? I have checked the engine oil, I have enough in there. Also I have noticed the psi is roughly above 1.

However the rpm is at 1200/300…timing is slightly off

Anyone experience this before?

Hy what engine do you have ? 

EvilDust said

Hy what engine do you have ? 

Its a standard 1.8 with the original carb….

I should have added I added the vdo gauges back in march so I'm pretty sure it's not an electric fault. I've searched the forums and people have similliar issues but haven't come back with a solution….

The oil pressure drops after the engine oil is warmed up which is standard protocol …..it flickers between 1-2…..

If I rev the car above 2000rpm oil pressure increases to above 3…….


So the red light flashes once the engine oil is warm at 80, if I slow down and it hits the 1200 rpm it starts to flash then…..even when the car is stationary…the oil pressure now is on 1 flickering slightly below and above

I can't hear any noises from engine, but the tappets are very noisy…..

Minimim oil pressure in my cabby must me 2 bar at 2000 rpm with the oil temperature at 80°C. Oil pressure switch and gauge sender warns with a flashing light, when oil pressure falls to near zero and sends pressure reading to center console bar gauge. That says "cabby info".
My vdo readings:
When engine cold and high idling it shows about 4 bars.
When it reaches working temp at idling it drops to 2 bar.
While driving at normal speed 4-5 bars.

(1 bar = 0.068947)

If the tapets are very noisy maybe something wrong in piston oil rings? if yes engine must burn oil, and white smoke must be seen from exhaust pipe..

Do you checked spark plugs? How does it looks like? 

EvilDust said

Minimim oil pressure in my cabby must me 2 bar at 2000 rpm with the oil temperature at 80°C. Oil pressure switch and gauge sender warns with a flashing light, when oil pressure falls to near zero and sends pressure reading to center console bar gauge. That says "cabby info".
My vdo readings:
When engine cold and high idling it shows about 4 bars.
When it reaches working temp at idling it drops to 2 bar.
While driving at normal speed 4-5 bars.

(1 bar = 0.068947)

If the tapets are very noisy maybe something wrong in piston oil rings? if yes engine must burn oil, and white smoke must be seen from exhaust pipe..

Do you checked spark plugs? How does it looks like? 

Yea spark plugs are fine, I serviced the car myself only two months ago. Don't think it could be that….

I'm gonna start the car now and leave it for 20 mins to warm up to see if any white smoke comes out …..

It cant be the oil pump because I read the engine should be making a lot of dodgy noises…..

There's no oil leaks the sender..

The spark pulgs can show if there is a problem with piston rings..

EvilDust said

Minimim oil pressure in my cabby must me 2 bar at 2000 rpm with the oil temperature at 80°C. Oil pressure switch and gauge sender warns with a flashing light, when oil pressure falls to near zero and sends pressure reading to center console bar gauge. That says "cabby info".
My vdo readings:
When engine cold and high idling it shows about 4 bars.
When it reaches working temp at idling it drops to 2 bar.
While driving at normal speed 4-5 bars.

(1 bar = 0.068947)

If the tapets are very noisy maybe something wrong in piston oil rings? if yes engine must burn oil, and white smoke must be seen from exhaust pipe..

Do you checked spark plugs? How does it looks like? 

So there's no white smoke coming from the exhaust nor can I see any smoke from the engine or signs of a leak….

Did read the instrument panel could be faulty?

But I've noticed when the light flashes the engine fan comes on……

Is there "vdo" oil pressure sender unit?

EvilDust said

Is there "vdo" oil pressure sender unit?

Yea there is mate….the sender is connected to the side of the engine block…

When you added the VDOs did you use new separate senders or tap into the existing senders/wiring?

Early-1800 said

When you added the VDOs did you use new separate senders or tap into the existing senders/wiring?

I used new seperate sender's mate. The wiring and the sender's were all new as I never had them previously…

EvilDust said

The spark pulgs can show if there is a problem with piston rings..

So I just checked the spark plugs in the engine….all four were fine….although the one on the right had little black bits init

is that dirt camed with spark plug from cilinder? or you grabed it from somere else when taked spark plug? 

Did read the instrument panel could be faulty?

Yes it could. But you must check oil pressure sender unit with voltmeter. Every reading has own resistance. Like in this photo. You have to measure it and compare with "characteristic curve"   

EvilDust said

is that dirt camed with spark plug from cilinder? or you grabed it from somere else when taked spark plug? 

I think the dirt came from the cylinder…it was the far right spark plug. Rest of them were clean

EvilDust said

Did read the instrument panel could be faulty?

Yes it could. But you must check oil pressure sender unit with voltmeter. Every reading has own resistance. Like in this photo. You have to measure it and compare with "characteristic curve"   

I'm not sure how to use a voltmeter to measure the ohms…..

How to use a voltmeter (DVOM) to measure stuff.
How to Use a Multimeter - SparkFun Learn

Electrical Primer to teach you basics…
http://volkswagenownersclub.com/vw/showthread.php/32254-Electric-Primer

Basic tools to work on electrical stuff on your car….
http://www.toplessrabbit.com/forums/viewtopic.php?f=7&t=3211

Briano1234 said

How to use a voltmeter (DVOM) to measure stuff.
How to Use a Multimeter - SparkFun Learn

Electrical Primer to teach you basics…
http://volkswagenownersclub.com/vw/showthread.php/32254-Electric-Primer

Basic tools to work on electrical stuff on your car….
http://www.toplessrabbit.com/forums/viewtopic.php?f=7&t=3211

Cheers Briano1234 really useful and a lot of info to digest!


I understand a bit how to use the voltmeter to read but I'm slightly confused where to put the black and red pin on the sender……as I selected ohms on the voltmeter reading and stick a black and red on each pin but didn't get a reading (please see picture of sender )

The way to connect a DVOM is that your single spade connector on that sender, is where you place either one of the leads, as when measuring resistance it doesn't  matter which lead is where for resistance, it is only a matter when you are reading a solid state component.

One lead is on the spad, the other on the case as the case is the ground.

To get the resistance range you have to apply pressure to the part.

On DVOM's getting the leads wrong will give you a negative reading in the same amount as the positive.

The only thing I will warn you about is DO NOT SWITCH SCALES with a meter attached, as if you aren't very careful you will blow it the meter up and you won't believe how much smoke they can put in that little device….

In 40 plus years of working on electrics/electronics on everything, I have only blown 1 meter up which was about 2 hours after making the remark that I have never blown a meter up (KARMA) glad it was my 6 dollar meter…. then I loaned my Son-in-law my new meter, and he fried that one…

So in 1 year I have had to buy 3 different meters.. This one has a LARGE display, and can do a variety of things from duty cycle/dwell to temps and
frequency….