New engine????

[20vtmk3]

Hi guys, Done a compression test on my s3 on wednesday night after it failed its m.o.t on emissions. The result i got were 13,10,11,13. Ive made a search and cant find out wat they should be. Went to buy a Hayes manual but it didnt cover the s3. The car smokes a lot when its first started up but on the go it doesnt seem to smoke any more than most cars. Is there a chance it could be the turbo? Im not very clued up on engines so i dont want to spend on something i dont have to. When the car is started from cold you can smell oil burning! Any help would be very much appreciated, thanks for reading.

 

[1animal1]

the S3 is notorious for smoking loads of white smoke on start up....from cold obviously

the other things im afraid i cant help with fella....good luck with it though, although i would say that they arent renowned for the head gasket going which may be some comfort

 

[Mr.G]

Valve stem oil seals???

I've seen this happening on an S3. It disappears after a while then comes back intermittently. By smoking on startup is it white (ish) smoke or black?

I might be wrong. Could be something else. Is it smoking every startup?

G

 

[20vtmk3]

It does smoke on most start ups but worst when its cold, the smoke looks white to me but the garage i took it to says that when they left it running in the garage it did turn blue. What do you think of the compression test results?

 

[Broken Byzan]

Compression is even ish, so i bet within spec. My guess would be turbo failiure, It will let some oil directly into the exhaust causing failiure of emissions etc. What are the plugs like? Oily ? Or ok , if they are ok my mind is deffo turbo. If they are oily then i spose you suddenly could have widespread compression failiure. Not a usual failiure in my experience

 

[20vtmk3]

Thanks mate, The spark plugs were like new, no signs of oil. A mate told me that you shouldnt have more than 1bar difference between the cylinders,thats why im so concerned about the readings. Ill be chuffed if it is just the turbo, dont want to go taking the engine apart unless i really have to.

 

[ash_pearce]

the turbo wont cause different pressures in the cylinders mate, piston rings, leaking head gasket or poor seating valves will though.

piston rings will give you some smoke aswell.

 

[ash_pearce]

also 13 bar to 10 bar is 45 psi difference thats not acceptable, ideally 10% across all four pots is the norm.

 

[Broken Byzan]

I wasnt sure whether it was a wet or dry test, that will prove the rings/bores etc

 

[h100vw]

The engine should be at operating temp too.

Gavin

 

[20vtmk3]

Thanks for the replys guys, looks like an expensive job then. The garage that did the m.o.t for me said that if i was going to do the valve seals then i might as well replace the piston rings, big end shells and main shells while the car is off the road. The car has covered 112k miles so it would probably make sense to change the lot just to be on the safe side. Thanks again for the replys, very much appreciated.