Need some input! Cloud of grey smoke on startup

[J.P.]

UPDATE TO THIS THREAD SO YOU DON'T HAVE TO READ THE WHOLE THING TO KNOW HOW IT WAS RESOLVED:
I ran out of time / patience / ideas for solving clouds of grey smoke on cold start, and had the car tuned. NO MORE CLOUDS OF GREY SMOKE ON COLD START. The tune deleted the MAF, and EGR (EGR was left in place).


ORIGINAL POST

I need some expert eyes help me diagnose a grey smoke issue. I have searched tons of threads on similar issues, but can't seem to pinpoint mine. Here's the story:

New to us 01 Golf with 396k mile. One owner (tdi clubber) meticulously maintained miles. Bone stock with EGR still intact. Drove perfect for us for 2,000 miles. Now it is producing a giant cloud of grey smoke on startup. To me it is grey, it might be considered blue to others. UPDATE: To me it smells like oil, not diesel. Here's what I know / have done:

On cold start (no glow plugs) it now cranks for about 3 compression cycles before it fires, then is rough and stumbly for a bit. It produces a GIANT cloud of grey smoke. Passers by comment, I hang my head in shame.

It used to fire quickly. If I disconnect the coolant temp sensor and force glow plugs it fires right away and there is less smoke (still seems smokey though)

If I start it and keep it parked at low revs until the engine is fully up to temperature it continues to produce grey smoke. (rpms always below 2500)

If I start and drive it, smoke is visible through the rear view mirror on acceleration, or with rpms at 1200 or so. This continues until it is fully up to temp (normal rpms for driving, shifting at 3k regularly)

Removed pancake pipe a day after the idle to temp test. Intercooler is clean, no oil drained out.

UPDATE: Ran the engine with the pancake pipe off. No oil coming from the boost hose from the turbo.

Look at timing via VCDS. Right on the blue line when engine is both cold and warm. Graph says timing is within spec.

Look at measuring block group 04. Start of injection specified vs actual. 0.4 BTDC vs 0.7 BTDC.

Look at measuring block group 13 for IQ balance. 0.78, 0.56, -1.20, -0.14. Not great. Injector #3 is pretty far out of spec. IS THIS ENOUGH TO CAUSE THIS MUCH SMOKE?

Compression test when warm. All values were very close. 460, 460, 440, 460 (and 450 on #1 again) (HF gauge and 50A charger on battery). I haven't done a cold compression test yet.

Logged meas blocks 03, 04, 05 during the warm up cycle, and did the same with our 02 Golf. However the 02 has EGR delete and a tune so they were not an apples to apples comparison and I could not detect something way out of spec. WHAT DO I NEED TO LOOK AT HERE?

Recent new air filter, snow screen cleaned, fuel filter filled with diesel purge.

Recent new CCV and grommets due to a lot of external leakage. Recent new gaskets on oil cooler due to a lot of external leakage. I can't speak to oil consumption because these leaks were pretty significant, and I haven't driven it more than 100 miles since they were fixed.

Recent CEL for "valve for intake manifold flap". It had the wiring worn through due to the corrugated plastic wiring cover (common issue). Spliced in new wiring. No more codes.

What do you experienced tdi guys think this is pointing to? What else do I need to do to diagnose it?

Thanks!

JP

 

[BobnOH]

Thoughts:
The glow plugs do operate beyond the squiggle glow, so fixing those may help. Check all the big piping is snug. Seems like the motor is in decent shape, hard to figure out, but it should be something simple.
The fact that it warms all the way up at idle could indicate some extra friction. Maybe inspect the cam and stuff.
A can of Diesel Purge run straight might help, but if those are the original injectors, they could just be quite worn.

 

[J.P.]

BobnOH, thanks for the response.

My understanding is Glow plugs do not come on until temp is below 45 degrees. They are definitely not getting any voltage now (55-75 degrees here) even though the gp light is on for a second or so. I should check my other car to see if its glow plugs get voltage in these conditions.

For clarification. With my start and idle test, more rpms than idle got it up to temp. I was bringing rpms to 1200 frequently so I could look for the smoke, as I was trying to see at what temperature the smoke would stop.


They are 2nd set of injectors, but I don't know how old. I do have another set of injectors of unknown condition I could swap....

 

[WildChild80]

What does the smoke smell like? Oil has a distinct smell as does fuel

Does it feel like it's making the same power as it did before the mosquito fogging started?

It sounds like fuel if I had to guess, you could swap injectors and see if it makes any difference

Did you check that you didn't knock anything off in the process of the repairs like a vacuum line or something. I bumped a vacuum line one time, the one to the bulb and the car ran very bad...


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[J.P.]

UPDATE:
Just ran it with the pancake pipe off. No oil coming out of the boost hose from the turbo. Think I can logically rule out an oil leak on the intake side of the turbo. It could still be on the exhaust side of the turbo, but that doesn't explain the longer crank time.

Still clouds of smoke. To me and my son it smells like oil, not fuel.

Still takes 3 compression strokes to fire, and runs rough for a bit. This would seem to point to oil in the combustion chamber. If this is correct and it is not coming from the turbo, what is left? CAN IT BE FROM CCV OR EGR?

Is there a good test procedure to diagnose bad CCV or EGR function?

I have decent hot compression numbers, but have not tested cold compression. That is on my list to do.

Also on my list is to start it with a 50A charger on it to rule out a weak battery influencing the start.

 

[csstevej]

I would pull the glow plugs after the engine sits overnight.
See which one is wet.
I had a similar problem but for me it was first start of the day I would get a big cloud then most would go away but still be there.
I pulled my head and found that one of the valve seals was leaking overnight into the combustion chamber causing my Smokey starts and haziness.
I originally didn’t pull the head for the smoky issue I pulled it because I had a broken GP and head had about 394,xxx miles on it, figured it was time.

 

[KLXD]

Pump getting air in causing late timing and smoke???

Has it had new seals?

 

[dogdots]

csstevej nailed it.

I'll bet the valve guides are very worn at that mileage. I rebuilt a head on a Beetle (ALH) that I bought with a broken timing belt, it had 130k miles on the original belt when it broke.

I was surprised at how much wear the valve guides had when I took the head apart. I ended up replacing all 8 guides in that head when it went back together.

With worn valve guides the valve stem seals can't do their job so just replacing the seals won't fix the issue.

If it is only happening after sitting long enough to cool down oil is likely leaking into the cylinders past the valve seals. Same issue as the old small block Chevy's always had after they accumulated some miles.

 

[Nero Morg]

Nobody has asked yet, are you having to add oil to your engine regularly? If you're not losing oil, it may not be your valve seals. Air intrusion in the fuel from sitting overnight can also cause smoky starts but clear out. Could be the fuel return lines between injectors and IP, along with the thermo t not sealing fully. Just a thought.

 

[csstevej]

Op states it smells like oil to him and his son.

 

[J.P.]

Thanks for the suggestions. It does smell like oil to me, but I am no expert on diesel exhaust smell diagnostics.

I'm not ruling out fuel, but will try to get more data to diagnose an oil problem first. I will be pulling glow plugs to check for oil on them tomorrow, and I will do a cold compression check.

Regarding adding more oil, I haven't driven it far with this issue, probably 120 miles on it since the symptoms started. This has come on very quickly. 3k miles of trouble free driving and very normal starts, and then within 3 start intervals, clouds of smoke.

 

[J.P.]

UPDATE:

Pulled the glow plugs this morning, and all 4 were dry. Car was driven yesterday 35 miles of mixed rural driving.

Did a cold compression test. 460, 460, 460, 440 (and 460 again on #1).

Started it with a 50A charger still on the battery. It definitely fired quicker (like my other tdi), but still smokey.

 

[Nero Morg]

Have you checked your thermo t yet? If the o rings are leaking air, it'll cause the smoky starts, but clears after a minute or two.

 

[J.P.]

O rings look good and the thermo T seems to seat well.

However the rubber fuel lines to and from the filter have some age cracking on the exterior. They appear to be in good shape on the interior of the hose when I disconnect them.

Have you checked your thermo t yet? If the o rings are leaking air, it'll cause the smoky starts, but clears after a minute or two.

 

[jmodge]

Have you ever run a boost log to see what it’s doing at a lower RPMs?

 

[WildChild80]

Any updates? I'm curious to know what's going on

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[J.P.]

No solution yet.

I did a thermo T, and fuel filter swap from a healthy running car. It reduced the champaign bubbles in the clear supply line to zero, but still smoke.....

I'm compiling what I've done and what are still the open issues and I'll post a summary here shortly.

 

[Nero Morg]

If you've eliminated the filter, it's probably time for some nozzles.

 

[eddieleephd]

Hose is cheap, you should replace the return lines between the injectors. Eliminate the cheap things before jumping to nozzles.
When was the last time you had nozzles installed anyhow?

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[J.P.]

Things seem to be pointing towards injectors. Even if not, pulling the injectors will let me inspect the cylinder with a borescope and give me better data. I have a family member in the hospital, but will be gathering the tools and pulling the injectors as soon as I can. I'd like to swap injectors between my cars to see the difference before I order new, but that puts the good running ALH at risk.

I also have new hoses on hand.

Here's my diagnostic thought process. Let me know if you think I am off.

POSSIBLE SOURCES OF SMOKE
Bad glow plugs - non issue as problem occurs when GPs aren't called for
Bad timing - timing is spot on
Out of spec IQ - IQ is in spec

FROM OIL ENTERING COMBUSTION CHAMBER
Failing Turbo - no oil in intercooler, not spitting oil when run with pancake pipe off.
Valve stem seals - POSSIBLE usually wet glow plugs, mine are dry (however I consider this inconclusive).
Valve guides - usually continuous smoke, mine stops when warm.
Poor compression - cold and hot compression is decent and consistent
Bad top piston ring - POSSIBLE. it would likely be one cylinder only. How to diagnose?

FROM TOO MUCH FUEL
usually black smoke - mine is not black
overfueling - mine is stock tune
leaking injectors - POSSIBLE, but gps are not wet. Pulling injectors would show

FROM TOO LITTLE FUEL
Air in fuel lines – mine has no Champaign bubbles, runs clear.
Bad / leaking thermostatic tee fitting - swapped from a good car and no change
Bad drain fitting on fuel filter - swapped from a good car and no change
Plugged sending unit in fuel tank - POSSIBLE, but everything I read says you see bubbles if this is the case.
Bad seals in injection pump - POSSIBLE
Way out of spec injectors - POSSIBLE, my IQ balance is not great.

 

[eddieleephd]

Last thought is possible bad seal on IP letting air in. Only viable it it cranks a while before it starts.

Otherwise, it'll take a couple hours max to swap the injectors and run a test on both cars. Not a terrible amount of jeopardy for the health ALH so definitely worth the check.

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[WildChild80]

If you swap injectors, keep track of the seals and make sure you don't double them up

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[BobnOH]

Check the big piping, especially underneath. Air is a major component of fuel. Clogged air filter or snorkel will also cause bad fueling. Didn't read it all, but have you checked for any stored codes?

 

[JB05]

Your glow plugs should operate year round; regardless of ambient temperatures. The duration will be less in the Summer months.

 

[BobnOH]

Went back and did a quick read of page 1. If it just puffs when first started, yes, it could be the glow plug system. Warm engines run at near 200 degrees. If it's 40 or 90, engine is still cold. Also plugs glow after the squiggly turns off.

 

[KLXD]

Should get the CEL if de plugs aren't working???

 

[BobnOH]

Should get the CEL if de plugs aren't working???

Good point, the glow plug system is one of the better monitored system. Pretty much always trips a code for plugs, wires, relays and usually illuminates the CEL.

 

[J.P.]

Thanks for the responses. This is helpful!

Your glow plugs should operate year round; regardless of ambient temperatures. The duration will be less in the Summer months.

I found a lot of confusing info on this. I'm wondering if the confusion is GP operation from other engine models. My Bentley for the ALH indicates that "additional heat from the glow plugs is not needed until temps drop to approximately 48 degrees". Mine are not operating on startup and it is above 55 all the time here now. If I pull the coolant temp sensor all GPs work, and it diminishes smoke, but it is still there. So I ruled GPs out as an issue.

Check the big piping, especially underneath. Air is a major component of fuel. Clogged air filter or snorkel will also cause bad fueling. Didn't read it all, but have you checked for any stored codes?

Good point on reduced airflow being a possible source. I've checked the IC piping and there are no leaks, and monitoring boost seem normal to me. I did the air filter and cleaned the snowscreen recently, and the intake had been cleaned not long ago so I had ruled it out, but need to put it back on my list as a possibility. Maybe an obstruction somewhere?? All codes went away when I replaced 1 bad GP awhile ago, and fixed a seat connector for the airbag.

If you swap injectors, keep track of the seals and make sure you don't double them up

This made me realize I don't have new seals for the injectors - need to see if the local dealer has them..........

 

[J.P.]

What else should I inpect while I have injectors out?

Question for you all: What should I look for in the combustion chamber while I have the injectors out? I have a cheap HF borescope that I intend to use when I pull the injectors.

I intend to swap them while the engine is cold, so I can look for leaking fuel or oil. Any way to inspect valves to determine leaking guides or seals? Is it worth anything to rotate the engine and try to inspect the cylinder walls? Cold and hot compression seem solid (460ish and pretty even).

 

[jmodge]

You’re over thinking it, I assume, since your compression is fine. Sounds like fueling issue do to lack of air. Has fuel consumption gone up? How does it run if you stand on it? Have you graphed it? Since your injectors are out, swap them and see what happens, but the simplest and most cost effective diagnostic step is to graph it to make sure the turbo controls are working properly. If you’re up in the Gaylord area, you can always run over to Matt Whitbread and have him look at it. More cost-effective than throwing parts at it, and a lot easier to diagnose in person than online.