1.8t intermittent smoke (thick white with burning oil smell)

[grainqey]

So basically bought car with oil sludge in the header tank, intermittent temp gauge so changed the temp sensor, replaced damaged dipstick and drove fine, no smoke etc. (was chucking a bit of oil out of dipstick before I replaced it)

Changed oil cooler and refitted a couple of vacuum hoses with damaged ends kind of thing and now I get intermittent thick smoke on idle, doesn't seem to clear by revving but passes for a bit.... Then comes back. Could be related to engine coolant temp from watching the coolant temp go up on vcds and it start chucking smoke out.

I'm not sure if it's more likely pcv building up pressure or if it's engine coolant building up pressure then leaking or the same but with oil. Smoke is white with a slight blue in it

Thanks (I've come from 2.0tfsi and tried searching)

 

[Adrian R]

I would think oil sludge in the header could be from a head gasket failure. can you get a sniff test done on the coolant?

 

[QuattroCalum]

I would say that some of the oil sludge has made it's way into the pcv system. My advice is to totally remove the pcv system and clean it all out. First though I would order the crankcase breather pipe because this will break on removal if it hasn't broken already.

This complete kit will replace any parts that are or may break, it is made in China and it's up to you whether you buy it or not, Audi would relieve you of £20 plus for the crank case breather pipe alone.

https://www.ebay.co.uk/itm/Engine-C...724571&hash=item2359615526:g:os0AAOSwKIpV~pnu

I have run 1.8t powered cars for more than 12 years and you have already replaced the oil cooler which would have been my first suggestion but i think it has had a secondary effect on the pcv system. The inlet will be drawing some of the oil sludge into the turbo inlet pipe, remove and check the pressure control valve at the back of the valve cover that should give you a fair idea if this is the problem.

The only other problem could be the head gasket but you haven't mentioned the cooling system pressurising so i would dismiss that.

Which coolant temp sensor did you use, most recommend genuine only (at over £30) I've used Meyle or Beru with no problems, Ebay £2 ones with two year warranty are useless.

 

[grainqey]

I would say that some of the oil sludge has made it's way into the pcv system. My advice is to totally remove the pcv system and clean it all out. First though I would order the crankcase breather pipe because this will break on removal if it hasn't broken already.

This complete kit will replace any parts that are or may break, it is made in China and it's up to you whether you buy it or not, Audi would relieve you of £20 plus for the crank case breather pipe alone.

https://www.ebay.co.uk/itm/Engine-C...724571&hash=item2359615526:g:os0AAOSwKIpV~pnu

I have run 1.8t powered cars for more than 12 years and you have already replaced the oil cooler which would have been my first suggestion but i think it has had a secondary effect on the pcv system. The inlet will be drawing some of the oil sludge into the turbo inlet pipe, remove and check the pressure control valve at the back of the valve cover that should give you a fair idea if this is the problem.

The only other problem could be the head gasket but you haven't mentioned the cooling system pressurising so i would dismiss that.

Which coolant temp sensor did you use, most recommend genuine only (at over £30) I've used Meyle or Beru with no problems, Ebay £2 ones with two year warranty are useless.

Thanks for the reply!

I ended up taking the head and turbo off (I sorted all the vac pipes out and took it for a thrash and then found mayo on the dipstick)

The SAI pipe? on the drivers side of the engine was solid with mayo so blew that out with a tap and various pieces of wire/soaking/methylated spirits soaking)

I used a genuine temp sensor as I'd heard about the failing ebay specials.

As it is as the moment, I've replaced the turbo oil feed pipe and got silicone vac piping, replaced the turbo ( I wondered if it was possibly oil getting into the turbine housing with it being white and oily smell) if that lot doesn't mostly sort it then i'll do the PCV system - but i'll do the pcv system anyway

I'll have to see what happens when I start it up - hopefully it'll be sorted

Thanks

 

[QuattroCalum]

Thanks for the reply!

I ended up taking the head and turbo off (I sorted all the vac pipes out and took it for a thrash and then found mayo on the dipstick)

The SAI pipe? on the drivers side of the engine was solid with mayo so blew that out with a tap and various pieces of wire/soaking/methylated spirits soaking)

I used a genuine temp sensor as I'd heard about the failing ebay specials.

As it is as the moment, I've replaced the turbo oil feed pipe and got silicone vac piping, replaced the turbo ( I wondered if it was possibly oil getting into the turbine housing with it being white and oily smell) if that lot doesn't mostly sort it then i'll do the PCV system - but i'll do the pcv system anyway

I'll have to see what happens when I start it up - hopefully it'll be sorted

Thanks

Don't forget to clean the intercooler and throttle body as well.
There are two pipes that run alongside the head one is for secondary air injection pump and the other is positive crankcase ventilation.
The sai pipe should be free from sludge, I hope you just got them mixed up.
The engine wouldn't be able to breathe with all that sludge in there and that should be your problem fixed. Did you replace the pcv valve at the back of the head? Round UFO shape with two ports.

Sent from my ANE-LX1 using Tapatalk

 

[grainqey]

Thanks for the reply,
Do you mean the silver disc shape thing on the drivers side at the back of the head? or do you mean a black plastic one?

I've had the silver UFO off and looks clean though the pipe for the SAI that runs at the side of the head must have allowed a slight amount of air through, I ended up soaking this in alsorts after trying to poke it out having an adverse effect! eventually blew out what looked like a **** with a tap haha!

I've ended up removing the SAI pipe and pump but need to map it out (I've tried coding it out with vcds but it's one that defaults with it on so needs mapping out) added the bex intercooler while I was playing with it, as you do!

Still got the PCV to sort out but need to get it running as the mot is approaching

Thanks
Alex