Blue smoke from exhaust (intermittent)?

[rob - 73]

Not been on for a while due to just getting our first house...happy days.. It has a large garage and decent driveway. No more working in the rain for me...lol

Anyway, since last week I have been getting the following issue:-

After idling for a few minutes at the traffic lights, once the car has warmed up (30mins motorway), when I go to pull away from the lights I get one cloud of Blue Smoke from the exhaust.

It doesnt happen all the time, just getting more noticeable.

Also if the car is idling on the drive after a run, I can hear what sounds like oil drips hitting the exhaust or something hot.

My thoughts are valve stem seals, turbo seals or worse.

So what do we think?

Cost of repair / replacement??

Could it wait for a month like this???

 

[virdi]

Can you actually smell the oil burning.?

 

[grahams81]

Not been on for a while due to just getting our first house...happy days.. It has a large garage and decent driveway. No more working in the rain for me...lol

Anyway, since last week I have been getting the following issue:-

After idling for a few minutes at the traffic lights, once the car has warmed up (30mins motorway), when I go to pull away from the lights I get one cloud of Blue Smoke from the exhaust.

It doesnt happen all the time, just getting more noticeable.

Also if the car is idling on the drive after a run, I can hear what sounds like oil drips hitting the exhaust or something hot.

My thoughts are valve stem seals, turbo seals or worse.

So what do we think?

Cost of repair / replacement??

Could it wait for a month like this???

Sounds like your on the right lines yourself mate, turbo or valve stem oil seals..... maybe crankcase breather, check your breather set-up.

Maybe let it idle until it's smoking shut it off and remove a charge pipe and inspect inside for excessive oil.

Is it definitely oil thats burning i.e blue smoke ?

Oh and the oil dripping onto something hot sounds really dodgy - if it's doing that it could easily develop into a fire and burn the car out....so look into it as a priority.

Good luck and once you find out be sure to update the thread for others with similar issues

 

[rob - 73]

Cheers.

It's not white smoke, ie water vapour that's for sure, it's darker and blue.

I could only smell oil the once, after its was idling for a while, again it's kinda difficult to tell as it only smokes after idle when I press the accelerator and again only once.

The oil dripping onto something hot, is maybe a bad description, it might be a intermittent noise from the exhaust. Maybe a tapping / rattle / vibration noise from the new exhaust. It's difficult to tell, but that's got me well worried now.

Any other symptoms that could point me in the right direction?

 

[traumapat]

I had the same symptoms other than your "drip" and it turned out to be valve stem seals.

Someone will explain it far better than me but with mine the car was fine under load and wasnt burning oil but the moment the car stopped the pressure changed allowing oil to seep from the exhaust side.

My car ran like this for a couple of years. In fact it did it when I bought it so in my case a tiny drop of oil was all I was losing. No loss registered on the dip stick. I guess it depends how bad the seals are.

The problem is theres no conclusive test as far as I know, its a head off job and inspect.

As said check the breather system.

The cost is going to vary on the work the head needs. I think I paid 1200 but have heard some of the lads on here paying less. shop around. Not cheap I'm afraid.

 

[rob - 73]

Thanks, im just going to check the breather hoses just now.

I hope I'm not looking at a £1200 bill as that would be a killer.. I was hoping along the line of £400/£500.

Thanks again.

How would I determine if it is coming from the turbo or valve stem seals??

 

[grahams81]

How would I determine if it is coming from the turbo or valve stem seals??

Maybe let it idle until it's smoking shut it off and remove a charge pipe and inspect inside for excessive oil.

See above.

Oh and the reason they only burn oil when not under load - when the engine is idling it's creating a vacuum in the inlet manifold / behind the valves etc....that helps pull the oil past the seals... when it's under load the pressure is positive and helps keep the oil out.

 

[rob - 73]

Thanks mate, sorry didnt spot that..lol

I will give that a go, hopefully tomorrow, although I have some things I need to do in the house.

I'll see how I get on.

 

[8bit]

I had similar symptoms when my turbo oil seals were on the way out. I also had a noticeable noise, bit like an owl or a distant police siren, which rose and fell slightly behind the engine note, even off-boost.

I also had blue smoke but more noticeable when accelerating under boost, or rather on the over-run after being on boost.

I'd take your turbo intake pipe off the turbo and check the shaft for any play. There should be almost none at all. I drove around for the better part of a year with the funny noise and odd bit of blue smoke, eventually it got to the point where the car felt stuttery and hesitant under boost. If you have to hold off for a while just go easy on the car, stay off boost if at all possible.

 

[Mr OCD]

Just a different tangent ... is the car DECAT?

 

[rob - 73]

Quote:
Originally Posted by grahams81

Maybe let it idle until it's smoking shut it off and remove a charge pipe and inspect inside for excessive oil.


So with the LC (AUQ engine), am I right in thinking that I could remove the pancake pipe that runs up from the bottom of the intercooler and check that for excessive amounts of oil?

If there is excessive oil in there would this then prove that its the turbo thats leaking oil?


Sorry just trying to figure our which element is at fault...

Especially after the independant VW / Audi garage just quoted me approx. £900 to replace the valve stem seals....

 

[mk4 cupra]

From my experience if your valve guard steam seals where leaking. when u stop the engine and leve over night and start it up you would get a puff of smoke straight away. because the oil would be leaking through the seals into the bores and settled there.
So when. U start up of corse is comes out the exhaust. If this ain't the case I don't belive it's your stem seals

That's just my opinioun from what I have seen in versions cars in the past

 

[rob - 73]

I had similar symptoms when my turbo oil seals were on the way out. I also had a noticeable noise, bit like an owl or a distant police siren, which rose and fell slightly behind the engine note, even off-boost.

I also had blue smoke but more noticeable when accelerating under boost, or rather on the over-run after being on boost.

I'd take your turbo intake pipe off the turbo and check the shaft for any play. There should be almost none at all. I drove around for the better part of a year with the funny noise and odd bit of blue smoke, eventually it got to the point where the car felt stuttery and hesitant under boost. If you have to hold off for a while just go easy on the car, stay off boost if at all possible.

Cheers, I will have a look, holding off on boost though... that is very difficult...

I dont have any smoke under boost or when driving along at all, its just after the car has been idling then on the first blast of pressure through the exhaust pushes out the burnt oil...

Just a different tangent ... is the car DECAT?

Nope not decat...

 

[rob - 73]

From my experience if your valve guard steam seals where leaking. when u stop the engine and leve over night and start it up you would get a puff of smoke straight away. because the oil would be leaking through the seals into the bores and settled there.
So when. U start up of corse is comes out the exhaust. If this ain't the case I don't belive it's your stem seals

That's just my opinioun from what I have seen in versions cars in the past

Thats interesting mate as i dont get any smoke on start up, only once the car has heated up. I though this might be something to do with the oil getting thinner at its higher operating temperature?

 

[rob - 73]

I have just had a chat with Sevice manager at seat, who has always given me great and spot on advice in the past.

He agreed that if it was the stem seals that were leaking I would notice the smoke at start up 1st thing in the morning. Also that I would notice smoke of deceleration as well.

Suggested that I take up to relatively high revs in 3rd gear then come off the throttle (losing about 15mph) then accelerate hard and I should see a large cloud of smoke if it is the valve stem seals.

Hopefully it is turbo related as this could be a good chance to upgrade at the same time...lol

 

[8bit]

I'd say turbo was more likely, based on the hours of searching I did when I had blue smoke I found far more posts relating to turbo oil seal failure than valve stem seals. Easy way to check though as I said, take the TIP off the turbo and check the shaft for play. If there is any then the turbo needs rebuilt (if you're lucky) or replaced.

 

[mk4 cupra]

Rob 73 just got to say are u defo sure it's. Blue smoking because I have just fixed my car and I could of swore it was blue smoke I was seeing.
I had a blown off boost pipe was causing it to smoke when I wa sat in traffic and pulled off slowly then would stop.

It caused it to white smoke with a hint of black due to the car was putting the right amount of fuel into to engine but not enough air so of cause it was the wrong mixture causing it to smoke.

 

[rob - 73]

I will check the pipes after dinner, just incase...

Will keep up posted, cheers.

 

[leero783]

Had the same problem after CHANGING a turbo found out it was the oil return from the turbo to the sump and causing a backlog of oil in the turbo and not burning i.e smokey on idle . If it is turbo make sure u check both feed and return . Does it do it when cold because this never only when hot . Perfectly fine on a run just smokey at idle . Hope this helps and goodluck

 

[rob - 73]

I would say white with blue, not black although not dark blue.

All hoses look fine.

Yeah, it only does it when hot, no issues at all when cold.

I still need to check the feed and return to the turbo also pancake pipe and the turbo itself.

So you think it could be a blocked pick up pipe to the sump?