Blue smoke - but what could cause it?

[fubar andy]

Earlier this yeah my turbo gave up big time after a session at Outlon Park (if not, much earlier; but with me being me I just carried on until total failure).

Anyway, the turbo was given a full re-haul and upgrade; once back I bunged it back on and drove around normally to make sure all was well :thumb:

So far so good! 8)

Anyway a trip down to Silverstone in March for my track day showed a few issues of smoke again and I was a little concerned about whether the turbo was ok?

At first I hardly noticed the smoke until a few days later when I took the car out for a post-shakedown from the track day to make sure all was well.
However on gear changes I noticed that there was a puff of blue smoke when the car was hot and 1st thoughts that it might be the turbo.

I did a bit of youtube scouring to see if I could find any videos of my car on track to see how bad the smoking was:

Skip to 4:20 and you can see what I'm on about - click me

Anyway with one thing and another I put it back into the garage as I had other more important pressing things to deal with.

Long and sort is, I pulled out the car today to give it a check over and also address the possible turbo issue or smoke problem.

Again I took it out for a quick blast down the back lanes, watched all the gauges and the rear view mirror for smoke.
Without fail, once hot the car puffed out its 1st blue smoke cloud, nothing too big, but it was noticeable in the rear view mirror. After a little more speed and rev's the smoke became more apparent, normally taking place at high rev's when I changed gear (5k+)

Tonight I've removed my turbo ready to be taken back to the shop so they can inspect it and perhaps diagnose (what I think it might be is the turbo seals) if it’s gone Pete Tong. However if not than I'm left with perhaps something more serious to contend with.

As for "other information" about this, once I removed the turbo there is oil in the intake/intercooler pipes, however what I did find a little worrying was there was a little (only a light film) of oil before the turbo in the air intake pipe (where the rocker cover breather is directed into the intake pipe - I've not bothered to install a fancy pants chrome catch tank)

Oil consumption over the month has been more than normal, that'll be down to the amount that's been coming out of the exhaust pipe!

To finish my main question, if the turbo is in perfect working order, what else could be causing these issues? Perhaps stem seals or worse?

Engine had a rebuild about 18 - 24 months ago and since then has pretty much been on track 6 or 7 times and steady motorway miles getting to and from the circuit.

Any other possible ideas or things I could check?

 

[PobodY]

Do you have a catch can, or are you venting from the case back into your intake pipework? - It's reasonable that hot oily vapour could get forced out of the crank case and through the turbo resulting in blue smoke... maybe a bit of a long shot if your oil levels are ok... and might suggest bigger problems if it is the case (like an exhaust leak into the crank case or a leaky piston).

Is it a journal or roller bearing turbo? - Is it possible that you're forcing too much oil through ball bearings (if that's what you've got) and it's spraying into the compressor housing?

 

[stumo]

i'm waiting for the vid to download....

You will get a slight film in the inlet if you're still using the stock PCV setup...i wouldn't worry about that.

The puff of smoke could either be the turbo (which you're having checked) and would show up by the inlet after the turbo would be wet with oil as opposed to the thin film before your turbo.

It could be the stem seals, these can and do go hard/brittle after time (or if the engine is sat doing nothing for a while) and that means they don't seal very well

Or it could be the oil rings but you can usually have smoke at any rev, not just on gear changes.

 

[fubar andy]

Do you have a catch can, or are you venting from the case back into your intake pipework? - It's reasonable that hot oily vapour could get forced out of the crank case and through the turbo resulting in blue smoke... maybe a bit of a long shot if your oil levels are ok... and might suggest bigger problems if it is the case (like an exhaust leak into the crank case or a leaky piston).

Is it a journal or roller bearing turbo? - Is it possible that you're forcing too much oil through ball bearings (if that's what you've got) and it's spraying into the compressor housing?

I’ve not bothered to install a fancy pants chrome catch tank it just vents back into the system, but its not enough to warrant the “more than normal” oil consumption!

I’ll pass on the info about the bearings, but the system I have set-up should not over load/flow the bearings so I’ve already put that to one side

The puff of smoke could either be the turbo (which you're having checked) and would show up by the inlet after the turbo would be wet with oil as opposed to the thin film before your turbo.

I have both of those issues, but much more oil in the intercooler pipes

It could be the stem seals, these can and do go hard/brittle after time (or if the engine is sat doing nothing for a while) and that means they don't seal very well

Or it could be the oil rings but you can usually have smoke at any rev, not just on gear changes.

It has been sat around mid last year, but from October ’09 onwards its been run at least 2-3 times a month or taken on a track day. Do stem seals have a shelf life if not used often?

I did think about oil rings, but since is normally puffing when changing gear that kind of quashed that idea?

 

[pulsarboby]

i noticed this whilst you were on track andy but i did not want to mention it and potentially ruin your day.

ok i reckon its the tubby itself, ive never had any success with rebuilt turbos, they just never seem to last very long for whatever reason.
i very much doubt it will be stem seals, but if i were you i would compression test it to make sure theres not a prob with a cylinder, block etc.

we all know by now that these engines just dont last on the circuit for any period of time but i do believe your prob still lies with the turbo, which in a way is a good thing if im correct;-)

 

[fubar andy]

i noticed this whilst you were on track andy but i did not want to mention it and potentially ruin your day.

ok i reckon its the tubby itself, ive never had any success with rebuilt turbos, they just never seem to last very long for whatever reason.
i very much doubt it will be stem seals, but if i were you i would compression test it to make sure theres not a prob with a cylinder, block etc.

we all know by now that these engines just dont last on the circuit for any period of time but i do believe your prob still lies with the turbo, which in a way is a good thing if im correct;-)

If you see anything like that again or something that might be worth a word about don't hesitate to mention it to me. I'd rather know if there is something potentially wrong with the car, rather than letting it fester and cause catastrophic problems. :thumb:

I'd like to think its the turbo overall and from looking at all the clues I'd like to think my diagnosis will be right. However these things are never than simple and in a conversation I had to my mate who said "hopefully it'll be something simple" to which I replied "nothing with a GTiR is simple" I like to think he might be right.

Either way I'll look at doing a comp test and see the outcome of that and also the report on my turbo.

Out of interest (a question to all) is there a procedure to running in a rebuilt turbo or can you just bung it on and hammer it from the start?

 

[pulsarboby]

tubby doesnt need to be run in, as long as its primed with oil it should be fine from the off

the next thing youll get back from the turbo builders is 'its been starved of oil or similar':roll:
dont let them fob you off with that, its just a way of them getting more money from you to avoid doing the job under warranty, and obviously dont tell them the cars only been used on track once lol.

it wasnt bad on track but as you said there was a puff of smoke when changing gear.
what with the crap day i was having and the fact you were all happy i didnt want to ruin it for you tbh and besides as said it wasnt that bad at the time, i initially thought it may have been some oil residue left in your ic or pipework from before you had turbo repaired!

but do the comp test anyway at least that will put your mind at rest that its not your engine.....hopefully!

 

[fubar andy]

tubby doesnt need to be run in, as long as its primed with oil it should be fine from the off

the next thing youll get back from the turbo builders is 'its been starved of oil or similar':roll:
dont let them fob you off with that, its just a way of them getting more money from you to avoid doing the job under warranty, and obviously dont tell them the cars only been used on track once lol.

Cheers for the heads up, the guys are pretty sound who I've used, but will keep it in mind!

 

[velly4]

Maybe a leak down test also???

 

[campbellju]

Compression test isn't definitive as I've just found out :-(

The breather system has casued me problems in the past with it not venting the crank csae and rocker properly. The hotter and thinner the oil got, the bigger the puff on the overrun as it went anywhere it could.

Could be the oil return feed not flowing well enough? Probably not if yours is OE style but just another idea.

 

[PobodY]

The breather system has casued me problems in the past with it not venting the crank csae and rocker properly. The hotter and thinner the oil got, the bigger the puff on the overrun as it went anywhere it could.

I think that's almost the opposite of my suggestion, but still along the same lines; it's oil getting into the cylinders from somewhere other than the turbo. - That's made me think I should make the effort to clean mine out.

 

[fubar andy]

Turbo is now in the shop, they are going to take it apart, test and check to see if there are any issues with it.

Hopefully I should know more for the weekend :thumb:

 

[fubar andy]

Ok, turbo back and the report is in perfect working order.


I'm going to install it later today and take it out for a blast round the block just to make sure that it's still got the same symptoms and not "suddenly" stopped smoking :roll:

If its the same I'll have a look at the breather system, see if that's blocked?

 

[fubar andy]

Ok, well the goal posts have moved now. :doh:

After installing the turbo and sorting out all the ancillaries I'm now in an even shittier place that I was before.

Took the car out for a drive and without fail once up to temp, the smoke bellows out on gear changes or when I lift off the power at high rev's.
The smoke only last for a second, just comes out in one big puff when the vacuum changes.

What's more interesting is that the smoke it more black than blue now (check the video I posted earlier and it now looks like that). Even worse the boost has risen from 0.8 bar to 1.1/1.2 with it peaking at 1.4 bar!!!

Now some will know I don't run a boost controller and just let the standard system deal with the boost, which has worked perfectly for the last 5 years of ownership (at 0.8 bar).

The boost spikes at 1.3 or 1.4bar when I change gear at high rev's/high load. The boost pressure then resides back to 1.1/1.2 bar constant.

I've also re-directed the breather pipe from the cam cover (which connects to the air intake) and made a make-shift catch tank to see what would come out of it? After some hard driving there was not a single bit of fluid or oil residue in the pot, but still the car pumps out smoke from the rear? :sad:

I also monitored all the gauges and everything thing still works perfectly, but I'm still a little confused about what's going on.

I know before the boost hike (which has only happened since i re-installed the turbo) the fuelling was spot on as I attended the GTiROC rolling road day.

Any thoughts? :noidea:

 

[pulsarboby]

have you done a compression test yet? if so whats the readings?
could possibly be similar to what happened to my car on rollers once, ie cracked head betwen valves

do the engine checks as above plus a wet test on cylinders to see whether head or cylinder related

 

[fubar andy]

have you done a compression test yet? if so whats the readings?
could possibly be similar to what happened to my car on rollers once, ie cracked head betwen valves

do the engine checks as above plus a wet test on cylinders to see whether head or cylinder related

Not had chance to get hold of a pressure tester yet, will be my 1st thing to do tomorrow - I'll post up my findings once done.

 

[red reading]

Valve stem seals or valve guides,i reckon anyway

 

[fubar andy]

...but what would suddenly cause the boost to rocket up?

 

[pulsarboby]

they may have fitted one of those little electric turbo fans inside your turbo to give you another 200 billion bhp:lol:

 

[fubar andy]

ahh not a foofoo valve then :lol: