Oil Disappearing-burning Or Leaking?

[leon 1.9 0]

Ok guys I'm pretty new here but I thought I'd ask about a problem with my 1.9 GTi. The oil level seems to be dropping quite quickly (fell below min. 2 weeks ago, needed 2 litres to get back to between max and min), so its either burning it or leaking it.

 

I don't think its leaking as there are never any puddles or oil marks beneath the car when I park up.

 

Therefore I'm assuming its burning it. I'm using 10W40 mineral oil (Castrol GTX), so I'm not sure if its the right grade.

 

The thing that puzzles me is that theres rarely any blue smoke from the car even when I rev it, although a little comes out at start-up if I don't drive it for several days. The oil pressure gauge also seems to be showing good pressure, and changes with revs as I would expect it to. Pressure drops at idle when the car gets hot, but this seems as normal for any car.

 

I know the next step is to compression test it but I'd like to know whether the GTi's have a tendancy to burn through one source- do the wear valve seals out, blow headgaskets, or wear piston rings often?

 

The oil seems clean and the coolant doesn't appear contaminated so I'm suspecting valve seals or piston rings. Hoping its top end as I would like to get a top-eng overhaul done soon anyway along with cambelt.

 

Any advice?

[jackherer 543]

almost certainly valve stem seals I'd say. get someone to drive along behind you to see if it smokes on the overrun.

[hengti 2]

i'd go stem seals first too. it's the first thing that goes and causes oil burning. your other options are guides and/or rings. ime, shot stem seals can account for the loss of alot of oil

 

usually shows on start up and whilst coasting down from high revs. warm everything up and and boot it up to the limiter in second; back off completely and watch for a cloud in your rear view. likely stem seals - relatively cheap and easy to fix. contentious, but no need to remove head to have them done.

[leon 1.9 0]

Thanks. had my brother follow me on his motorbike, sure enough the only time it smokes is during the over-run from high revs. Using a lead replacement additive for the past two weeks and the oil loss has reduced greatly, along with me not giving it quite so many revs.

 

Looks like I'll be on a trip along the south coast to QEP then. I want the cambelt done anyway just so I don't need to worry about it, so probably get it all done together.

 

The engine's been adjusted to run rich by the previous owner, so the oil smoke is mainly hidden by unburnt fuel, which is why when my brother mentioned it when I test drove it I wasn't too worried. Its got worse since then though.

[futura 3]

Out of interest, why are you using mineral oil? Semi synthetic is recommended in these engines

[Grim.Badger 15]

Check the dizzy seal as well as when mine went I lost a lot of oil, but it never puddled when standing.

I thought GTX was semi-synthetic

Castrol imo gets lost very quickly through bad valve stem seals compared to other oils.