Oil light keeps coming on but oil level is fine.

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marcman
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Oil light keeps coming on but oil level is fine.

Post by marcman »

My oil light has just started coming on. Usually comes on after about 10 mins of driving. I've checked the oil level and it's absolutely fine (from cold on level surface). It will go out every now and then but will always come back on again a few minutes later. The beeping is starting to get on my nerves.

I'm going to be taking it in for a service in about 4 weeks (can't afford any sooner) and I'll get them to look at it then.

In the meantime, IS IT SAFE TO DRIVE?

Cheers for any advice
Marc
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alexperkins
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Post by alexperkins »

It sounds like oil pressure perhaps. Get it checked as soon as you can bud
polo2k
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Post by polo2k »

Hi there, Dont come on here often at all but just spotted this post.

Marcman please dont take this as an attack but your post highlights something really well (and I feel like a bit of a rant ;) )

Im more into classics than I used to be and If you saw the oil light on a classic, you would assume it was the oil pressure and get dirty looking at it. Modern cars are now so dependable that as soon as we see a light we assume its an electrical problem when it could be much more serious!

In answer to your question, look at the end of the head and you will see a sensor screwed into the end of it, check the wireing is plugged in on this. If it is then DO NOT START THE ENGINE. the reason being that if the wireing is plugged in ok then its one of 3 things:
1) dead sensor or borken wire (annoying fault)
2) the sensor is working but not "seeing pressure" (potentially serious)
3) somthing else (the start of many hours of diagnostics)

It is possible that its number 2, in which case it could grenade your engine in a matter of minutes (if not already) and it could range from low oil level, thru blocked galleries to a failled oil pump

So, back on track. please check that you have oil pressure and that it is indeed the electrics that have failled you because otherwise you will have a big bill

P.s. doesnt it seem odd that hte oil pressure warnings dont come into effect until 2.5k RPM, dont engines need oil at tickover lol :roll:

heres a pic of my old steed to keep the flames at bay!
Image
adummy
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Post by adummy »

i got this problem aswell

but my light only comes on under 2000rpm and i just changed the oil pressure switch (and the wire is fine) but its still the same :S???

anybody got any ideas???
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Post by Bepe »

polo2k wrote:
In answer to your question, look at the end of the head and you will see a sensor screwed into the end of it, check the wireing is plugged in on this.

i could of swore blind, if it is that one thats the camshaft positions sensor?
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alexperkins
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Post by alexperkins »

Camshaft is in the middle to the right of the rocker cover. But it depends on the engine
marcman
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pressure sender

Post by marcman »

OK, thanks for the replies, especially 'Ash'.

I've had a chance to look a bit closer and I 'think' I've found an oil pressure sender switch with a small oil leak. The switch in question is at the front of the engine to the right, just sticking out from underneath the plastic cover that sits on top of the engine (see images below). Is this an oil pressure sender switch? You can see the oil on the engine behind the switch in the second image.

Anybody know the part number of the switch?

Thanks in advance
Marc

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adummy
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Post by adummy »

thats the same one thaat i changed aswell

i couldnt find another one though and asked at my local vw stockist and they said that it only had one they called it an "automatic something oil pressure switch"
but some people on here say that there are two :S so i dont know :?:
adummy
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Post by adummy »

the part number is 03091908/D

or 03691908/D (i cant tell if the 3rd digit is a 6 or a 0 :? sorry) :lol:
polo2k
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Post by polo2k »

that looks right.
To get one give VAG parts a call (in my signature) and they should be able to help out (youll need your engine code though)
id also check the rocker cover gasket because that looks like it could be leaking from above and then running over the sensor.


As i said before:
If the light is on dont assume that its an electrical fault. maybe, just maybe, the electrics are fine and its the oil pressure thats at fault. that wont be terribly obvious before the engine sounds like a washing machine full of spanners! AT THE LEAST GET THE OIL PRESSURE CHECKED WITH A GAUGE!!!
marcman
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Post by marcman »

Thanks Ash and Adummy

Ash - I'm 90% sure that the oil you see in the photo has come from the sensor and sprayed behind due to the windrush when motorway driving, but I will take a closer look as you suggest.

I took the plastic cover off the top of the engine this morning and pulled the connector off of the switch. As I did so some oil spilled out of the end of the sensor, from inside - not a big amount, just a trickle. I put my spanner to the nut that screws the sensor into the engine and tightened it up - I wouldnt say it was exactly loose but it did tighten about 1/8th of a turn without me needing to force it.

I then took the car out round the block a couple of times and the light did not come on. The engine was warm when I began and would usually come on quickly. I then disonnected the switch again and cleaned all the oil off, from inside the connector and inside the end of the sensor. I will take the car out again on my lunch hour and see what happens with the light. The fact that there appears to be oil escaping from the inside the sensor makes me think i should replace it regardless!

I'll report back when I've taken it out again.
Marc
marcman
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Post by marcman »

Right, I drove the car to a VW parts shop. My oil light did not come on during the journey. I checked the switch one last time before I went in and it was still leaking oil from the centre where the connector plugs in.

I purchased a new switch - part# 03691908/D (thanks Adummy) - removed the old one, screwed in the new one, all done.

My 35 mile journey home tonight will be the test!

As a precaution I will get the oil pressure checked when its serviced in a couple of weeks.

Thanks
Marc
adummy
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Post by adummy »

my oil light is still coming on :(

im gonna change the oil sensor tomorrow could someone please tell me where it is located?

ive already changed the pressure switch but it hasnt cured it
Helloraay
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Re: Oil light keeps coming on but oil level is fine.

Post by Helloraay »

If you have a classic polo - and had your oil changed/ car serviced recently at a garage, chances are you've had the wrong oil put in such as synthetic or semi synthetic oil. This stuff is too thin for older cars but says it can be used on any car on the tin, so unless they specialise in classic cars or VWs they just wouldn't know.
Try not to drive the car until everything is checked out and the correct oil (15W40 oil) is used.
This is the case with my 1984 polo which had several visits to the garage and had the switches and sensors replaced countless times!
Hope I shed some light!!
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937carrera
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Re: Oil light keeps coming on but oil level is fine.

Post by 937carrera »

marcman wrote: In the meantime, IS IT SAFE TO DRIVE?

Cheers for any advice
Marc
Marc,

Though I suspect this isn't the advice you want to hear I'm going to suggest that you take the advice of polo2k, assuming the correct oil is in the car

Oil pressure drops when the oil gets warm (i.e. thinner)

It is unusual that the oil pressure light is not on when at idle when the engine is warm as oil pressure is also lower when revs are lower( subject to pressure relief valves), so maybe not an oil pump / bearing issue in the engine.

Personally I wouldn't run the engine until you have had the oil pressure checked with an external gauge. - Your call if you choose to use the car for the next few weeks and you end up needing major repairs. I hope not :(
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