Trouble with an oil pressure switch on a Mk3 1.4 Golf

[spocks_beard]

Hey Guys, this forum looks great! I'm hoping someone out there will be able to help me.

I have an oil leak, quite a big one, that im 99% sure is from the oil pressure switch. I was told by VW when I quoted my chasis number that I would need a 1.4 BAR replacement item, which I got from a local shop, not the dealer. I fitted it and the oil light wouldn't stop flashing, whereas before it went out after starting the engine. I decided to take it out and order the part from VW incase it needed to be a VW specific part (I'm not very mechanically minded), put the old one in and the light stopped flashing again.

When I got the part from VW I fitted it and the same thing happened, the oil light wouldn't stop flashing. I drove it round for a bit to see if it would make a difference but it still kept flashing.

Basically I was wondering if the dealer has given me the wrong part, or if the part is right and its my car thats doing something wrong. I'm getting desperate because its leaving a huge puddle of oil on the road.

Also, the water level in the coolant seems to be dropping sometimes, could this have anything to do with it? As I said, I don't know much about engines.

Thanks in advance for any help you may be able to give,

Steve

[weed]

You have checked and added oil to the sump, correct??
m

[spocks_beard]

Yeah, the level keeps dropping quite fast, thers a nice big puddle under the car. I traced the oil from the top of the engine downwards, and it looks like its coming from the oil pressure switch.

[Pickled Piper]

There are two oil pressure switches in the vicinity of the oil filter.

Sorry can't type more I'm in a hurry.

pp

[Pickled Piper]

Ok now I've got a bit more time. The oil leak you describe is a common problem on MK3s. Most variants have two oil pressure switches one that operates the light and the other that sounds a buzzer. The two are differenr ratings. I don't know if the thread size is the same could you have got the wrong switch in the wrong hole?

pp

>> Edited by Pickled Piper on Tuesday 14th March 11:38

[zcacogp]

Pickled Piper said:

Ok now I've got a bit more time. The oil leak you describe is a common problem on MK3s. Most variants have two oil pressure switches one that operates the light and the other that sounds a buzzer. The two are differenr ratings. I don't know if the thread size is the same could you have got the wrong switch in the wrong hole? pp >> Edited by Pickled Piper on Tuesday 14th March 11:38

If it is as I remember, the switches are almost physically identical, just that the bore of the hole inside them is different, allowing activation at different pressures.

Make sure that you have the right switch in the right hole.

BTW, if you think that the switch is leaking, find out why and how. Two options. 1. It is leaking because it is not fitting tightly enough into the hole - probably because the copper sealant washer is damaged or not working as it should. Or, 2. It is leaking because the inside of the switch has fretted through the internal sealing membrane (quite common on that design of switch) and it is leaking through the switch, and out around the contact.

If the problem is 1., you may be able to fix it with a new washer (cost around £0.02p). DON'T re-use the old washer on a new switch, even if the failure mode is 2. above.


Oli.

[weed]

If both senders are to spec, but the warning beacon is lit, It might be worth finding out what the oil pressure actually is at idle and at 3500 or whatever the gearing at cruise lets the engine rev at.
If you have around 100k miles on the car the warning system may not be faulty at all.
m

[spocks_beard]

Thanks for the help guys. When I phoned VW they never mentioned that there were 2 switches, I think i must have been given the wrong switch for the one that is leaking, I'll get the other one and try that.

Thanks again.

Steve