Blue smoke on startup

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
Hello everyone.

So today my friend started my car while I was standing outside. Upon morning startup I saw a puff of blue smoke. After we made some 15 miles trip and the car wasn't used for half an hour, he started the car again to drive home. Blue smoke appeared again.

The car doesn't smoke while driving. I haven't noticed blue smoke on startup earlier, although never stood outside when the car was started.


Any clues if this is normal or should I start to worry? The car has got ~115k miles at the moment.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Some is normal, especially when cold (even says so in the owner's manual).

I watched the salesman start my PD up cold when it was brand spanking new and it did that.
 

DPM

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Joined
Mar 16, 2001
Location
Newtownards, N. Ireland
TDI
2019 Rav4 AWD Hybrid, Citroen C4 BlueHDI
Wife's 307 does it from cold, my Subie can occasionally do it hot or cold. Possibly valve-stem seals, possibly assisted by the low compression of today's engines, but definitely nothing to panic about.
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
How cold is cold? This happens even on warm engine.
Okay, valve-stem seals, piston rings... But what, at 115k miles?! :eek:

And the guy in the video has got only 36k miles on the car... :confused:

Strange but I've never noticed this happening on my car before. :(
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
As far as I remember, the problem wasn't here before the timing belt change (3 weeks and 500 miles ago). Water pump, thermostat and coolant were replaced too. Is it possible something wasn't set right at that time? The shop did use cam and crank lock tools and let me check when the tensioner was tensioned. The arrow was within the small window. VCDS Torsion value is 0.0 and doesn't change when accelerating high. Since fuel consumption at idle (Group 015) is 0.6 l/h, I'm almost sure the 0.0 reading is actually 0.0 and not 'out of range'.

During the job fuel and coolant lines were disconnected from the aluminium lines above cylinder head to make room for TB change. Is it possible that some contaminants got caught inside the fuel system and possibly damaged one or more fuel injectors?

Also, could this excessive smoke on startup be caused by a clogged air, fuel or oil filter?

This issue makes me loose my sleep at night, I'm sure it wasn't there some time ago. There might be some serious problem(s) developing... :(
 

nord

Veteran Member
Joined
Mar 5, 2010
Location
Southern Tier NY
TDI
All turned back to VW. Now a 2017 Hundai Tuscon. Not a single squalk in 10k miles.
Incomplete combustion due an excessively lean condition... Usually white smoke. Same as if gasoline is substituted for diesel.

Oil in exhaust system... Whitish to blue smoke. Keep an eye on your oil level.

Water in the system... White smoke. Make sure you have no antifreeze smell in the exhaust vapor.

In all three cases your smoke will have a definitive smell. Either unburned petroleum or coolant.

And one last thought... Northern Ireland in the spring. Cool damp air. Probably saturated at near the dew point. This is conducive to making water vapor until the tail pipe and cat warm up at which point the vapor becomes steam and is invisible.

Right now I'd not lose too much sleep.
 

sheepszies

Well-known member
Joined
Oct 26, 2010
Location
Montreal
TDI
2006 BRM 6 Speed
Blue smoke you say? Must be a smurf stuck in your intake.

(Nah but a little smoke on startup is always normal)
 

Dieselducky

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Joined
Oct 13, 2011
Location
Dunnville
TDI
88 Jetta Diesel - 2000 Jetta TDI - 04 BMW M3 - 06 Kia Rio - F350 Superduty - 87 Buick GNX - Mobile Cranes
My 2000 has done it since new even when it's 20C outside
 

Ski in NC

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Joined
Jul 7, 2008
Location
Wilmington, NC USA
TDI
2001 Jetta ALH 5sp stock
Completely normal. If smoke persists while driving or otherwise while fully warmed up, then worry. Puff on start, no big deal.
 

nord

Veteran Member
Joined
Mar 5, 2010
Location
Southern Tier NY
TDI
All turned back to VW. Now a 2017 Hundai Tuscon. Not a single squalk in 10k miles.
You, sir, have a problem! The question is just where?

Obviously the turbo will be suspect. Best to remove and inspect the lower intercooler line for excess oil. If none, then at least you can pretty much eliminate the turbo on the intake side. The problem being that if your loss is on the exhaust side it will be a more difficult task to detect. (Intuition tells me this is where you'll find the problem.) Check for turbo shaft play.

Next suspect would be a valve seal. Is there a chance that you lugged the engine and overfueled over a fairly long duration? This would have caused your valves to have been exposed to excessive heat which might have resulted in either a valve problem or possibly a leaking valve guide. Obviously a crack in the head at the right place will cause similar problems.

Last but not least is a broken ring. Usually the wiper ring and not the compression rings, but not always. This is possible but unlikely as the bottom end of these engines are not known to have failures.

In any case I agree that every engine will use oil. The thing is that a healthy engine should easily go between scheduled oil changes without significant oil use. This is a lesson I learned the hard way on a Continental O-540. A couple of quarts missing after 10 hours and the manufacturer said the use was within limits. My intuition said otherwise.

Long story short... I pulled the cylinders. No. 5 wiper ring had disintegrated. In the process it had allowed No. 6 to be scored. So two new cylinders, rings, and seals. All of the sudden an engine that would go a full cycle without noticeable oil use.

In any case... Ouch! This isn't something you can ignore. Good luck.
 

Ski in NC

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Joined
Jul 7, 2008
Location
Wilmington, NC USA
TDI
2001 Jetta ALH 5sp stock
Henrick- make sure you are consistent in when you check the oil. If left overnight, lots of oil drains back into sump and level may rise 1/4". Best is to check with with engine fully warmed up a minute or two after shutdown.
 

attyjeff

Well-known member
Joined
Jul 28, 2009
Location
Tallahassee,Florida
TDI
2009 Jetta wagon TDI
I have a porsche turbo that does this, my problem is the seals in the turbo has allowed oil to pass down and pool inside the turbo, then when it starts it blows smoke, its not a lot of oil but this tells me the turbo will have to be rebuilt one day.
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
Thanks for suggestions!
I always check the oil just after I shut off my car and always at the same place - my garage. So inaccurate readings are not possible I think.

Never been lugging the car or overfueling it (for extended periods). And I try not to drive the car like a grandpa. At least once a day when the engine is fully warmed up I try to upshift at redline.

I pulled the IC piping at the bottom of the IC. Some oil dripped down. It wasn't a measurable amount but there was more of it than a few drops.

Oh, and no visible leaks to the outside. At least I can't find/see them. Will be keeping my eye on this matter.
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
Okay. Since no one has any ideas and I'm tired of smoky startups, here are some my ideas.

I've noticed the smoky startup around 2-3 days after my timing belt was replaced. i don't know but it might be just a coincidence. Now before the replacement I had my Torsion value adjusted to 0.0 and I know it was exactly 0.0 since under hard acceleration sometimes it showed 0.5.

After the timing belt was replaced (lock tools were used) the Torsion value was 0.0 without any fine tune. However, I do remember the mechanic had a little problem inserting the crank lock. Cam lock slided in but the crank needed to be turned by wrench a bit for the lock to go in place. Now I remember my timing was at 0.0, right? Strange.

Now I have smoky startups. Is it possible that the timing is actually too advanced or too retarded causing unburnt fuel to turn into smoke? And VCDS simply shows 0.0 as 'out of range'.

Is there any cheap and dirty way to check if the timing is actually at 0.0 or is it out of range reading? Also, is there a chance that the cam position sensor was disconnected or damaged (wiring or sensor itself) during the TB job?

Any input is appreciated. Thanks.
 

skeith5

Well-known member
Joined
Apr 20, 2010
Location
WA
TDI
2006 Jetta
Is there any cheap and dirty way to check if the timing is actually at 0.0 or is it out of range reading? Also, is there a chance that the cam position sensor was disconnected or damaged (wiring or sensor itself) during the TB job?

Any input is appreciated. Thanks.
You can loosen the 3 camshaft pulley bolts and adjust the timing to one side or the other. Check your torsion values again. Then change the timing to the opposite side of where it was and you should have a number on the other side of zero. For instance, if you are dead on at zero and you move the pulley clockwise in relation to the camshaft and get a torsion value of 2, I would imagine if you moved the pulley counter clockwise past the 0.0 mark you would have a negative number.

You might want to turn the engine over by hand a few times before starting the car up just in case you are off enough that it causes interference.

When I replaced my camshaft I did the above when I hit 0.0 just to make sure it was true zero and not just out of range. For what it's worth my '06 doesn't use any noticeable oil between changes and I've never seen blue smoke..

Scott
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
I thought about that. The only thing holding me against doing this is fear of scerwing possibly perfect timing. It will be really hard to get it to the place it actually was in that case it's at true zero right now.

That's why I'm looking for some other way to check.

Maybe I should observe some measuring blocks in VCDS? Injection quantity, etc etc?
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
OK. The cam timing is really at 0.0 and not "out of range".

The car suffered from a turbo failure. I replaced the turbo (with a used one), filled with oil, changed the air filter... The car still smokes on startups. I haven't driven it for the weekend at all and when I started it on Monday morning it smoked more. It even smoked when I started driving the first 10-20 meters....

Any ideas what might be the cause of the smoke? This car never smoked like that before and it's not climate/humidity related. I don't have excessive amount of oil in the IC plumbing.
 

James & Son

Veteran Member
Joined
Oct 10, 2008
Location
Maryhill, Ontario, Canada
TDI
2006 Jetta
Any ideas what might be the cause of the smoke? This car never smoked like that before and it's not climate/humidity related. I don't have excessive amount of oil in the IC plumbing.
I would suspect the turbo again because it it used.

But when I changed out my valve springs I found a bad valve stem seal that had been damaged from the original factory assembly. The torn area was oxidized from heat and age so I new I did not do it. So that could be a remote possibility. My seal had one side of the seal damaged causing the lip tension spring to slip out of position and ride against the valve stem.

Because you do a lot of stop and go driving and probably idle the car the used turbo will probably show more oil loss than maybe the car it came from. Maybe check the drain back from the turbo to the sump is not a problem. You may also have an oil leak now that the turbo has been replaced causing you to think you are using oil. Maybe that extra zddp you have been putting in has caused your catalytic convertor to be less efficient and makes it seem smokier.

If you can ellimainate the above then it might be the valve seal which can be replaced quite easily. You will have to figure out which cylinder it is by maybe looking at the glow plugs for carbon.

Also before doing any of the above just start running diesel clean at high dosage rates to help clean out carbon deposits which could effect rings, valves and turbocharger and injectors. What is your fuel milage has it gone down causing incrased oil dilution. This is where diesel clean might solve a multitude of small problems.
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
I really doubt this is turbo. The shaft movement was minimal. IC plumbing has very little to no oil in there. Oh, and last weeks I was doing more highway driving.. Turbo drain back pipe was replaced when the turbo was swapped. At the same time the cat was cleaned with some chemicals.

I did Diesel Purge (used 1 liter of DP) this spring when I noticed the problem. It did nothing to the smoke...

And all glow plugs have similar quantity of carbon buildup on them...
 

Ski in NC

Top Post Dawg
Joined
Jul 7, 2008
Location
Wilmington, NC USA
TDI
2001 Jetta ALH 5sp stock
So it was smoking on start, using oil, and then you replaced the turbo just recently? Have you driven it much with the replaced turbo? If turbo was just replaced you may need to drive it hard to clean oil out of the pipes.
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
So it was smoking on start, using oil, and then you replaced the turbo just recently? Have you driven it much with the replaced turbo? If turbo was just replaced you may need to drive it hard to clean oil out of the pipes.
Okay. It was using oil during the whole time I've owned the car. Never any smoke, neither at (cold/hot) startup nor at WOT.

I've noticed it smoking at the end of the winter this year.

Turbo exploded around 6 weeks ago. Replaced it. I knew it had much oil in the downpipe so the mechanic cleaned the downpipe with chemicals and washed everything with compressed water & soap. When the car was back on road, yeah, it smoked for the first two days. I did a serious Italian tune-up (WOT @ 6th gear for ~1,5 hours, speed 118-120 mph.). No more smoke.

It now only smokes on startups, just the same it used to be before the turbo failure....
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
It wasn't 120 mph straight freeway but actually driving back and forth with speeds up to that. Driving way over speed limit is risky business but still, how to get those EGTs really high?
 

Scintilla

Member
Joined
Dec 11, 2010
Location
Ontario
TDI
2006 PD WagenRocket, 2000 Golf, formerly an '86 Jetta Turbo Diesel, Diesel Rabbit
'06 PD Sportswagen Smoke . . .

Firstly, I love my TDI wagon. I too, have an amazing puff of blue smoke at startup after the car has sat for a number of hours, but especially overnight. It does not show any excessive oil consumption on the dip stick. The blue smoke does not smell like diesel, so it's probably not an injector issue. I have not dismantled the intake side of the intake, but I've wondered about a weeping turbo seal. Alternatively, there might be oil coming from positive crank case ventilation system into the intake side which might be a plausible explanation. However, the fact that it blasts blue smoke only at startup signifies to me that the oil is already in the cylinder at startup. This points to compromised valve seal(s) and possibly an excessively worn valve guide. I will get a chance to dig into this more thoroughly in a couple of weeks. I'm determined to find the cause. Are there any VW service techs reading this site? I suspect this is a factory documented performance issue somewhere. Regards, Brian.
 

James & Son

Veteran Member
Joined
Oct 10, 2008
Location
Maryhill, Ontario, Canada
TDI
2006 Jetta
Okay. It was using oil during the whole time I've owned the car. Never any smoke, neither at (cold/hot) startup nor at WOT.

I've noticed it smoking at the end of the winter this year.

Turbo exploded around 6 weeks ago. Replaced it. I knew it had much oil in the downpipe so the mechanic cleaned the downpipe with chemicals and washed everything with compressed water & soap. When the car was back on road, yeah, it smoked for the first two days. I did a serious Italian tune-up (WOT @ 6th gear for ~1,5 hours, speed 118-120 mph.). No more smoke.

It now only smokes on startups, just the same it used to be before the turbo failure....
Is there any oil in UK that is actually a 15 cst oil at 100 C. Just go to a conventional group II 15w-40 as a test. It will stop using oil. If I use a thinner oil it burns more such as a 10w-30. Your 40 wt oil is extra thin to start with. The other thing you will probably have to do is replace your catalytic convertor.
 
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