Blue smoke when warm

Hi all can you help
Have a mk2 got twin turbo and now and again once fully warmed up if you blip the throttle while stationary say 3.5 to 4 k revs get as mall puff of blue smoke but drive up the road and accelerate hard nothing.
Bought the car 5 months ago and garage said they did oil change don’t know what grade etc and I’m thinking oil getting bit thin and seeping past valve seals and / or turbos??
Only thing haven’t checked is Pcv valve which would I be right in saying front rocker left hand side??

Yep check your PCV , it’s hexagonal shaped and screwed into the cam cover , take it off and it should rattle , if it doesn’t it’s gummed up , spray it inside with carb or brake cleaner until it rattles when you shake it .

Try that first as its cheap , also if your unsure what grade oil has been used it certainly won’t hurt to change it

Craig :grinning:

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Check if you got oil in the intake pipes if yes it’s turbo seals,could also be valve seals or piston rings
.I would change the oil if you don’t know put a fully synthetic like a 5/50 or 5/40,10/40,10/50
I use valvoline vr1 racing 5/50 and it’s the best oil used so far.

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Hello mate,

Check all your boost pipes post turbo, I find oil accumulates in the pipes from and to the intercoolers. If your getting smoke though it seems an excess of oil is entering the engine combustion chamber. How many miles have your turbos/car done? How thin is the oil your using ? I’ve used 5-40w and 5-50w before with brand new turbos and no smokey. Of course every body recommends and tends to use 10w50 thick stuff, which I also use.

I would suspect oil seals in the turbos. The pcv while recirculating case gases is unlikely to be dumping oil in quantities able to cause a visual smoke cloud, how ever small, into the combustion chamber. Unless the valve part of it inside has disintegrated, which is unlikely as I believe its made of metal and not exposed to excess wear.

As I mentioned, I have brand new turbos on my car with the old knackerd intercoolers, which are probably still full of oil from the old smoking turbos I took off, and my turbos are kicking out a little oil from what I can tell after cleaning one of the turbo out pipes, and I have No visual blue smoke what so ever, and I am sure I am burning a little bit of oil, infact the emission test on my mot was so close to the nutts it suggested nothing else.

Try a thicker oil and see if that reduces, it would maybe point to a leaky turbo seal.

Hope this helps or at least was entertaining

  • John

(Not a expert, Just a muppet with a wrench)


removed Pcv and was rattling so separated brake cleaner and quite a bit of muck came out but rattling now sounds louder so Poss partially blocked? Also removed boost pipes at y pipe and both clean and dry no oil whatsoever. Started car from cold warmed up no smoke but I did notice that after cleaning pcv car at cold Tickover is now 1200rpm seemed higher than before ? But then once warm dropped to below 1000 like before.
Will try see what happens but will get oil change as well piece of mind.
If that don’t cure it thinking now it’s not valve stem seals and maybe turbo seals. Car has done 90k and all original so maybe early signs of turbo ? If so they will get upgraded!! Lol


Hi John
If you ever want your intercoolers re-done, l assume oe, l have set up a recon exchange scheme, cheers Jerry.

My pcv was rattling so I changed it out, but it wasn’t blocked up. 90k is about the average lifespan of a turbo, so I am told. Could be the stems or piston rings. The obvious bet is to keep an eye on the turbo’s. Check the pipes further back from the y pipe, oil doesn’t collect much there or in the y pipe I’ve noticed. I find the pipes from the rear turbo and post intercooler collect a lot of oil and, if you have a standard bov or after market recirculating bov fitted check inside the intake splitter thing after the maf where the moulded passage allows the recirculated air charge to come back into the intake. Get a lot of oily crap there.

Hi jerry,

I Hope to eventually fit a front mount intercooler but you can pm me with details about your exchange service.