Another Blue Smoke Thread...

Another Blue Smoke Thread...[UPDATE]

Good morning,
I have a '97 B4 Passat with 312,000 on the clock and in the morning I have started to get a decent cloud of blueish-white smoke until the motor has warmed up.
The head was rebuilt about 30,000 miles ago so I do not think it is a valve seal issue, the turbo blows little to no oil(checked intercooler)
I do have a malone ecotune with the dynamic idle; would the extra fuel the dynamic idle is dumping in cause a smoke issue?
If there is someone with vag-com in my area(Neenah, WI) would you be willing to help me out and take a look at my timing?
Thanks in advance.

Small update: The smoke issue does not seem to be getting better/worse but when I started it up to leave work today it seems like it cranked slightly longer/harder than usual and it stutter/sputtered. Until it was slightly warmed up it had "rough" throttle response.
I decided to check my fuel lines for cracks/air when I got home and I noticed three small 1-2mm bubbles in the supply line. I will check it again in the morning and see if there is any more are ingress..
Again if there is anyone in my neck of the woods that can help me trouble shoot this it would be greatly appreciated. I've had a couple big expenses lately and bringing it to a mechanic is the last thing I really want to do at this time...
Thanks

Those bubbles aren't large or often enough to be a problem.

Check your intercooler for oil, drain if you find some (normal) and keep an eye on how much it is.

Are your glow plugs working? It's getting colder and if they're not working it'll do as you described. You won't get a light if they're all not working. A simple check with a multimeter will let you know if they're working or not.

Abacus said:

Those bubbles aren't large or often enough to be a problem.

Check your intercooler for oil, drain if you find some (normal) and keep an eye on how much it is.

Are your glow plugs working? It's getting colder and if they're not working it'll do as you described. You won't get a light if they're all not working. A simple check with a multimeter will let you know if they're working or not.

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I checked all of my glow plugs and the harness. I get 12V at the harness and the glow plugs are all within the .1-.5 of each other.

Little to no oil in intercooler.

Next?

As you were thinking in the first post, check the timing and report back. Could be slipping at the crank.

Yblocker said:

As you were thinking in the first post, check the timing and report back. Could be slipping at the crank.

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I'm trying to get it sorted out but I haven't found anyone with Vag-com in my area yet. Will update when I can.

That the smoke is bluish... Are you losing any oil?

I also don't think it would be valve seals - valve seals get to be an issue on worn gasser heads, as the intake is under vacuum and will suck oil past worn seals and guides into the intake to be burned.

On a diesel, the intake is slightly pressurized if anything - there is very little chance of oil getting past guides or seals unless they extremely bad.

In past, I have had issues with oil consumption on engines where the head was rebuilt but the bottom end was left alone - the newly improved sealing on the top end increased compression, and allowed the worn rings to pass more oil.

Windex said:

That the smoke is bluish... Are you losing any oil?

I also don't think it would be valve seals - valve seals get to be an issue on worn gasser heads, as the intake is under vacuum and will suck oil past worn seals and guides into the intake to be burned.

On a diesel, the intake is slightly pressurized if anything - there is very little chance of oil getting past guides or seals unless they extremely bad.

In past, I have had issues with oil consumption on engines where the head was rebuilt but the bottom end was left alone - the newly improved sealing on the top end increased compression, and allowed the worn rings to pass more oil.

Click to expand...

I am losing a little oil now and then but it is also seeping from a few places around the motor. I never thought about the "head seal" scenario, that is very interesting. I was also looking back in my records today when the timing belt was last done and last it looks like it was done was back in 2012, can the TB stretch over time? I opened the timing belt cover today and the belt looks alright(no cracks)

Yes, it can stretch and I have seen some that did so. It showed up on the Vag-Com easily enough.

Abacus said:

Yes, it can stretch and I have seen some that did so. It showed up on the Vag-Com easily enough.

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How does the strech show up through vag-com?

I would think that it would show most in injection timing?

Oh okay. Well I have an appointment to take it into a local VW shop Monday the 6th but if anyone is near by that would be interested in helping look at it I can compensate you for your time.

Otherwise I will keep you guys updated with what I find.

Okay well I took it into a shop to have it looked at and they couldn't find anything that would result in the symptoms I am having.... They basically told me it is simply having symptoms of a high mileage vehicle and if I really want to get it in tip top running condition I would need to do the rings. Well considering the mileage on the vehicle I may just deal with the "quirks" and drive it until "the wheels fall off"..

One thing I am curious about; I have no idea the last time the "pcv puck" on the valve cover was replaced. If it were bad would it create some of the symptoms I am describing?

Not likely. It is normally a straight shot through unless there is a slight restriction on the engine side then it closes.

My understanding is that if the vehicle rolls the oil flowing into it causes enough restriction that it sucks closed so as not to allow the engine to run away on the crankcase oil.

I've owned 2 B4 tdi's and they both did this to some degree. The 96 I have now is worse, puts out a bit of smoke (smells like diesel) at startup, seems to have no rhyme or reason, and is very random. Typically it does it more when its cold, but I've seen it do it warm too. To me it seems like too much fuel or the fuel is not combusting properly. I've also checked my fuel temp sensor and is within specification. I also have fresh glow plugs/harness.

If you want to see air infiltration into the fuel line watch the line with the vehicle running. If you see streams of bubbles moving into the IP you might be having a problem.

Since the return line from the IP to the filter is not clear on the OE lines you won't be able to see but if you had clear return line you might also watch that, froth in the return line would be a sign that there is too much air getting into the IP on the inlet side.

I'm not close enough to help you with vag-com, even when I go visit family in NE Iowa you're still a hefty drive, otherwise I would see what I could do.

As for what the shop told you I'd take that with a grain of salt. Not knowing anything about that shop I can't say whether they're speaking from any basic understanding of the TDI or not but the 'old high miler' response seems like it's an easy way to say we really don't know all that much about these engines.

My JY engine for the conversion from a few years back had 240k on it and still had the cylinder bore cross-hatching, and based on what that car looked like it probably didn't get the best care. I never did a compression test on it, which I probably should have, but I couldn't be happier about the way it performs.

Steve

Thanks for all the input guys. I'm slowly coming to terms with it being a high mileage car and having its "quirks". I agree though, the last time the head was off the bores still had cross-hatching as well and when its warmed up it runs like a champ. I'm thinking my short commute built up some carbon on the rings etc and I need to get that crap out of there!

I think at my next oil change I am going to run a can of diesel purge through the system and some BG109. If I notice any significant changes I will report back!

I ran a can of Diesel Purge through the motor yesterday afternoon. It sat from the time I ran the DP through it until this morning..... *drumroll please* .....NO SYMPTOMS! NO Smoke, NO Sputter, NO Hesitation just a nice smooth purr!

Anyone else ripping their hair out trying to track down excessive cold start smoke/rough starts try Diesel Purge; it really is “STRONG MEDICINE FOR SICK DIESELS”!

Good to hear your success with the diesel purge. I have used that stuff on both the B4's I have owned and never saw any difference in smoking or mpg.

Well the symptoms are back after a day or two.. now I really am ripping my hair out trying to figure this out....

I've had the blue smoke at startup for the past 10 years. Never really worried about it. Never notice it unless I let someone else drive.

Yeah, I'm learning to just deal with it.

Over the weekend I did order replacement fuel lines, a new fuel filter and a new "T". The lines from the filter to the pump and injector return lines are old so they may be sucking air when I start it.

I'll update if it changes anything.

Saturday I replaced my fuel filter, thermostatic T, return fuel lines between injectors and the factory fuel lines with 8mm rubber braided hose.

Usually it would smoke the most on the first start up after sitting over night. Well I went to run a few errands today and when I went to fire her up there was just a small puff of blue smoke and no surging under light throttle. As you can recall I was having really heavy smoke, sputtering and surging under light throttle until it was warmed up. Major difference after I changed everything listed above.