Hi guys,

Sorry to put urgent in the title of the first post I write but I may be up the creek with the paddles being washed overboard if I don't sort this out quickly.

I have a 1997 110, running the 300(?) TDi engine. It is the original engine and has only done 35,000 easy (but probably quite slow) miles. Engine oil and filter always changed at 3000 miles.

I let my father service her about 9 months ago (basically changing the oil and filter) - unbeknown to me, he overfilled her by about 1/2 to 3/4" up the dipstick and didn't take any of the extra oil out. So she's done about 2500 miles overfilled to that extent - not sure if this is relevant but it might be.

Anyway, I had to collect something on Monday which was about a 200 mile round trip with a trailer. Wasn't hammering her, no weight on really and stuck to below 65 all of the way. About 2 miles from home I hit traffic on the M1 for the first time. When she returned to tickover the oil warning light came on. As soon as I rev her anything above idle, the warning light goes out. I limped home very carefully turning the engine off at any stops.

I thought it might be that the oil had got overheated on the run as a result of the overfilling (reducing viscocity I think) so have changed the oil and filter and filled her back up to the proper level. Light still comes on at idle but goes out immediately there are any revs - just thought - idle is at the same level it has always been at.

The urgency comes about because I've built a car and it needs to be towed on a trailer to its SVA next Tuesday (why do these things always f***ing coincide??) and she's the only one I've got to do it.

I've read the previous posts and I'm going to get a mechanical guage to check the pressure and the sender unit. Anything else I should be looking for first and how much risk is there in using it next week to tow the car.

Thanks for any help and advice guys.

Doesn't sound too serious, oil pressure being a bit low at idle could be due to a number of reasons. When you changed the oil did you use an engine flush (warm engine, empty can in and run for 15 minutes at 1500 - 2000 rpm) then drain waste oil. This cleans the oilways and helps to maintain oil pressure.

Had a similar problem with my 200 tdi and all it turned out to be was the pressure switch on the side of the oil filter housing, which once replaced has not given any further worries. another cause is the pressure relief valve sticking but fom what you describe it sounds like a dodgy switch

The only real damage that overfilling with oil does, is blow gaskets or seals, or can sometimes cause smoking blue smoke.
The oil light coming on has no real relationship to what your dad did.
more than likely just switch , the mech guage or swapping switch will tell you for certain. HTSH

Thanks guys.

Couldn't just tell me where the switch is could you!

Jon

Single wire round switch by the oil filter. it is on 200tdi anyways.

Thanks for all the replies.

Changed the oil pressure switch and everything appears to have returned to normal.

I'm sure most of you have the same view about main dealers but I rang up this morning to get a rocker cover gasket for the 300 Tdi. Hadn't got one in stock so he looked at his computer again. Having looked he said that he would have to order 10 in so therefore I would have to buy 10. I politely declined the opportunity to pay £60 for a rubber gasket.

Can't really see the point in a main dealer having a parts department in those circumstances!

Glad to hear your switch fixed the issue, stay away from main stealers as much as you can, find a local indy they usually much more helpfull