Polo Drinking Oil

[taxman]

Hi there,

I've had a search through these forums and the net in general, but can't seem to find any answers to my problem (well, the problem with my 52 reg VW Polo 1.4 FSI anyway).

I haven't had the car for very long - it had about 45,000 miles on the clock when I bought it. I've since added a couple of thousand to that, but have had to top it up with around 3/4 litre of oil!

However there's no blue smoke, not a spot of oil dripped anywhere, and it starts and runs beautifully.

It's due for a service shortly so I'll get it checked out then, but in the meantime I wondered if anyone else has had similar experiences, or where the problem might lie (if there even is a problem!)

Any help / observations would be much appreciated.

Thanks

[Crasher]

3/4 of a litre of oil in 2 to 3 K isn't excessive but isn't good. Take off the air filter and see if it is contaminated with oil.

[GavHT]

My 1996 Polo has been a pleasant surprise on how little oil it drinks, so 3/4 litre seems quite a bit IMHO. I don't want to sound like I'm insulting your intelligence but you're reading the right marks on the dip-stick?

If its burning oil 'cos the piston rings are on their way out (although unlikley at the mileage) you may not see this as blue smoke under normal running conditions. The best thing to do is find a fairly long hill (doesn't have to be steep), put the car into neutral and let it run down the hill on no trottle. The pistons will keeping moving, splashing oil about and if your rings a knackered, splashing oil into the combustion chamber. When you get to the bottom of the hill put it into gear (not 1st!) and give it plenty of throttle - look out the rear-view mirror for blue smoke.

GavHT

[taxman]

Thanks for your messages Crasher and GavHT. Yes I can read a dipstick - no offence taken though, it's a sensible question. I also know it's low because I got a low oil lamp a few weeks ago too.

In an update to the saga, I had it serviced and MOT'd today. The garage said that the bottom of the engine bay / covers etc. are pretty clean and reckon it's not leaking anywhere. I assume they didn't find much/any on the air filter either (they were specifically looking for causes of oil loss and I assume this was replaced during the service - although I will admit that I forgot to ask them this question directly).

I will find a big hill and try your test tomorrow GavHT. It's too dark right now.

I did wonder if it could have been something to do with the previous owner using the wrong grade of oil? I have seen this reported on the net.

Does the 02 polo have the same engine as the 1996?

Thanks,

[Crasher]

The engines changed considerably between 96 and 02.

[GavHT]

I would be very surprised if the wrong grade oil leads to execessive consumption.

From what you're saying about the MOT, if there are no leaks the oil must be going somewhere. The only other exit is the exhaust. If you have a friendly garage nearby it would be worth asking them to do a compression test on the cylinders. This will definately tell you whether the piston rings are in bad shape.

[Crasher]

If an engine has failed oil control rings but good compression rings or good rings period and worn valve guides/seals, a compression test will not show a problem. A cylinder leak down test can be far more informative but will still not show worn oil rings or worn valve guides/seals. Diagnosing oil burning issues can be extremely difficult, especially on a car with a catalyst as the cat can cover up the problem to a certain extent by removing the odour and colour of the burning oil. Only when oil burning reaches a certain point will the cat and lambda sensor fail to function. His level of consumption is not high and will not cause cat/lambda failure. A 5w/40 (502 00) synthetic base oil will bypass the rings and various seals far more than a 15w/40 (501 01) mineral grade.

[GavHT]

Thanks Crasher, I've learnt something new.