Tdi alh puff of white smoke on start

[Nathan_og]

Hello everyone, I have a 2002 vw jetta tdi 5sp that I bought a few months back. When I start the car it has a puff of white smoke on start, I know some is normal but this seems a little excessive to me, also the rpms bounce 2 or 3 times very slightly and then as soon as it stops bouncing all the smoke dissappears. When I rev it there's some light haze blackish smoke when cold but a normal amount and barely noticeable when warmed up, little to no smoke. The smoke has a very strong diesel smell. I am also not loosing any coolant or oil at all.

Work done so far.
My mechanic said injectors were leaking so I had all 4 redone by performance diesel injection with .205 nozzles. Same puff of white smoke and rpm bounce as before but a lot less black smoke on wot.

Timing belt was recently replaced by last owner.

Last owner said he rebuilt the turbo, that turbo later failed on me so I replaced it with a used one. same smoke with old and new/used turbo. I talked with 3 diesel shops they all said they would not rebuild these turbos and they said if you do they will not last very long, I'm assuming that's why it failed.

Previous owner said he replaced glow plugs, glow plug harness, and glow plug relay. Unsure if he put new or used parts in.

Car also sat for a while with old diesel. I have already ran a few tanks of fresh diesel still no difference.

Vacuum lines do need replacing soon and the n75 valve has seen better days.

The fuel filter looks newer but I will be replacing and doing a diesel purge.

Any thoughts? The car runs great otherwise and has good power, the egr doesn't seem to be clogged but I didn't look very good at it. Thanks for the support guys really means a lot as its my first car at 18 and will be needing to commute reliabley to college.

 

[JohnTF]

How many miles on it ?
Has anyone done any aftermarket tuning , upgrades , etc. ?
Do you plan on learning to do any work on the car yourself ?
With the DIY = Do It Yourself stuff , and if the need for a reliable car , you may want to learn , and wait doing your own work , until you get to the point of knowing enough to have a running car after getting under the hood
But yes a little white smoke when you 1st start the car , and a little block when you get on it hard when cold & then gone with warm is normal .

 

[Nathan_og]

How many miles on it ?
Has anyone done any aftermarket tuning , upgrades , etc. ?
Do you plan on learning to do any work on the car yourself ?
With the DIY = Do It Yourself stuff , and if the need for a reliable car , you may want to learn , and wait doing your own work , until you get to the point of knowing enough to have a running car after getting under the hood
But yes a little white smoke when you 1st start the car , and a little block when you get on it hard when cold & then gone with warm is normal .

Thanks for the reply, im not sure if anyone has done any mods to it. And yes I'm pretty handy, I took a truck mechanic program through highschool and rebuilt 4cyl reefer engines. I also did a co op at peterbilt and am currently gonna be going to college for diesel truck mechanics. Also completed level 1 apprentiship. How about a slight rpm bounce? Is that normal for these?

 

[Nathan_og]

Thanks for the reply, im not sure if anyone has done any mods to it. And yes I'm pretty handy, I took a truck mechanic program through highschool and rebuilt 4cyl reefer engines. I also did a co op at peterbilt and am currently gonna be going to college for diesel truck mechanics. Also completed level 1 apprentiship. How about a slight rpm bounce? Is that normal for these?

Sorry it has a little under 300 thousand kilometers.

 

[JohnTF]

Most any symptom can have many causes , so off hand the RPM bounce , white smoke may just be unburnt fuel until engine is running for a few to 10 seconds about - until all cylinders are firing equally .
Getting an older / used VCDS cable , needed for most anything with these cars , a couple of the older ones are cheaper , partially because limited functions , that after 03 cables & car did more .
And at least a couple of the older cables where unlimited use , like the one I have KII-USB from Ross-Tech , https://www.ross-tech.com/vag-com/
I would suggest getting one of these to check the timing , after install of new timing belt there can be a little stretch and timing can vary slightly - I've read , have not done enough of the newer [ my last was an 85 ] to confirm .
Another common for yr. & millage is vacuum hoses needing replacing - they can cause a number of symptoms .

 

[Nathan_og]

Most any symptom can have many causes , so off hand the RPM bounce , white smoke may just be unburnt fuel until engine is running for a few to 10 seconds about - until all cylinders are firing equally .
Getting an older / used VCDS cable , needed for most anything with these cars , a couple of the older ones are cheaper , partially because limited functions , that after 03 cables & car did more .
And at least a couple of the older cables where unlimited use , like the one I have KII-USB from Ross-Tech , https://www.ross-tech.com/vag-com/
I would suggest getting one of these to check the timing , after install of new timing belt there can be a little stretch and timing can vary slightly - I've read , have not done enough of the newer [ my last was an 85 ] to confirm .
Another common for yr. & millage is vacuum hoses needing replacing - they can cause a number of symptoms .

Thank you. Definitely will replace the vacuum hoses. When I was getting the injectors done they checked the timing and said it was spot on. Do you think any adjustments can be made through vcds like extending glow plug timing? I'm pretty sure the smoke is unburnt diesel.

 

[JohnTF]

I'm not sure on which cars / which cables will change glowplug time , but generally it can be done .

 

[Diesel Fumes]

My alh has smoked on start up since I bought it a few years and 80k km ago. I thought about addressing the issue but I didn't. Still get 4.8l per 100km fuel economy and has good power and otherwise runs normal so I don't care

 

[Nathan_og]

My alh has smoked on start up since I bought it a few years and 80k km ago. I thought about addressing the issue but I didn't. Still get 4.8l per 100km fuel economy and has good power and otherwise runs normal so I don't care

Thanks for the reply, that puts me more at ease now. Not sure why the rpms bounce tho, its very minor and only for 2 or 3 seconds.

 

[csstevej]

Any idea what your IQ is set at?
I would check it with a VCDS when you can , set it to about 4-5…. See if your smoke on start up is less and see if your rpm bounce has stopped.

 

[Nathan_og]

Any idea what your IQ is set at?
I would check it with a VCDS when you can , set it to about 4-5…. See if your smoke on start up is less and see if your rpm bounce has stopped.

Thanks, I have no clue what its at. Do you know where I can buy vcds?

 

[csstevej]

You can got to the for sale section and see when people list them for sale.
You can go to the Ross tech website and buy one from them.
Your better deal would be a used , unlimited vin numbered one. The new ones from Roos tech are now vin numbered limited. They have several levels with the lowest costing one is three.
You can also go to the VCDS locator on this website and see if someone is close to you and contact them and work something out .

 

[Rrusse11]

Nathan,

With your training and background, and obvious enthusiasm, you NEED a Ross tech cable. As steve points out above,
you want an early unlimited VIN version. Keep checking the used forums, a fair price is ~ $150. The software to run said cable is free. A cheap laptop coupled with the right cable and you have arguably the most valuable tool you'll ever find for working on VW TDIs. Diagnostics and the ability to change many settings is essential for understanding and fixing these cars.

Your puff of smoke is probably unburnt fuel, leaking into the cylinder from somewhere. A touch of oil, or (eeks) some coolant are also possibilities. Once warmed up, all seals appear to be good, so don't sweat it too much.
Congrats on the ALH motor, many user/owners here on the forums love them as being possibly the best diesel VW built.
It has stood the test of time and durability. Relatively ez to work on, parts are still available and cheap.

Lots of good people here with a huge knowledge base on how to keep 'em running.

 

[jettawreck]

Thank you. Definitely will replace the vacuum hoses. When I was getting the injectors done they checked the timing and said it was spot on. Do you think any adjustments can be made through vcds like extending glow plug timing? I'm pretty sure the smoke is unburnt diesel.

Extending the glow plug duration is easy but not needed and would just be a masking "fix" for the issue, if there is one.
Injection pump, clogged intake and/or crankcase vent, etc, etc....
When you get around to becoming handy with vcds you can check and log a lot of data points and perhaps get some better clue as to what (or if) there is an issue. All my ALH cars have smoked a bit on cold start, sometimes quite a bit when it's really cold in northern MN.

 

[Nathan_og]

Nathan,

With your training and background, and obvious enthusiasm, you NEED a Ross tech cable. As steve points out above,
you want an early unlimited VIN version. Keep checking the used forums, a fair price is ~ $150. The software to run said cable is free. A cheap laptop coupled with the right cable and you have arguably the most valuable tool you'll ever find for working on VW TDIs. Diagnostics and the ability to change many settings is essential for understanding and fixing these cars.

Your puff of smoke is probably unburnt fuel, leaking into the cylinder from somewhere. A touch of oil, or (eeks) some coolant are also possibilities. Once warmed up, all seals appear to be good, so don't sweat it too much.
Congrats on the ALH motor, many user/owners here on the forums love them as being possibly the best diesel VW built.
It has stood the test of time and durability. Relatively ez to work on, parts are still available and cheap.

Lots of good people here with a huge knowledge base on how to keep 'em running.

Do I need a unlimited vin or can I still change parameters with the 3 vin one?

 

[csstevej]

You can do it with a 3 vin one.
The three vin one means that you can only use it on the first three cars that it’s plugged into.
It can be used many time but only on those three vin numbered cars….
The unlimited can be used on as many cars as you want……no restrictions , that’s why those are more money Or get a premium for them.

 

[Tdijarhead]

Here is where you can buy them new. You will need a laptop to download the free software from the Ross-Tech website to make the cable work.

VCDS | Product categories | Ross-Tech

Your MAF could also be getting lazy and allowing a little smoke.

 

[Rrusse11]

Nathan,
As steve points out, a VIN limited cable will do everything that the other variations do, but only for 3 cars.
If, as it indeed appears, you're already headed towards a diesel tech career, spring for the unlimited. You'll soon find a demand for your services. Frankly now is the time to get an unlimited cable, MkIV owners, as the early models die, or are upgraded, are slowly selling off their stashes of parts, "cleaning out the garage" is the seller you want to tap in to.
Once you start to use the cable and become aware of its quite extraordinary capabilities, you're of the generation that grew up with computers, you'll never look back. There is a cult following, and you're here in the right place.
Good luck young man, my bet is you'll never regreat learning about the diesel technology that drives the TDI.
Cheers!

 

[Nathan_og]

Here is where you can buy them new. You will need a laptop to download the free software from the Ross-Tech website to make the cable work.

VCDS | Product categories | Ross-Tech

Your MAF could also be getting lazy and allowing a little smoke.

Thank you so much

 

[Nathan_og]

Nathan,
As steve points out, a VIN limited cable will do everything that the other variations do, but only for 3 cars.
If, as it indeed appears, you're already headed towards a diesel tech career, spring for the unlimited. You'll soon find a demand for your services. Frankly now is the time to get an unlimited cable, MkIV owners, as the early models die, or are upgraded, are slowly selling off their stashes of parts, "cleaning out the garage" is the seller you want to tap in to.
Once you start to use the cable and become aware of its quite extraordinary capabilities, you're of the generation that grew up with computers, you'll never look back. There is a cult following, and you're here in the right place.
Good luck young man, my bet is you'll never regreat learning about the diesel technology that drives the TDI.
Cheers!

Thank you so much really appreciate the support, will definitely be buying a used one.

 

[Nathan_og]

Nathan,
As steve points out, a VIN limited cable will do everything that the other variations do, but only for 3 cars.
If, as it indeed appears, you're already headed towards a diesel tech career, spring for the unlimited. You'll soon find a demand for your services. Frankly now is the time to get an unlimited cable, MkIV owners, as the early models die, or are upgraded, are slowly selling off their stashes of parts, "cleaning out the garage" is the seller you want to tap in to.
Once you start to use the cable and become aware of its quite extraordinary capabilities, you're of the generation that grew up with computers, you'll never look back. There is a cult following, and you're here in the right place.
Good luck young man, my bet is you'll never regreat learning about the diesel technology that drives the TDI.
Cheers!

I found someone selling a key USB vcds, it has a grey cord and he says its unlimited vins and works upto mk4, is this one good? Or is there a diffrent model I should get?

 

[Tdijarhead]

Make sure it’s not a chinese/eBay knockoff.

 

[Gothmolly]

Same here, but it's kind of a cloud. And in winter, forget about it, full-on smokescreen.
The car's going on 19 years old now, it's going to have some warts.

 

[Nathan_og]

Ok heres a update, every time I start the car weather it's hot or cold I am getting a big puff of white smoke, zero coolant or oil loss. When I accelerate the smoke is blackish maybe even whitish, sometimes I start it and it does a huge puff sometimes it barely does any. One time I was sitting at a red light and accelerated and I saw a good amount of white smoke, another time none. Do I need a engine? Is a connecting rod maybe bent?

 

[Nathan_og]

Ok heres a update, every time I start the car weather it's hot or cold I am getting a big puff of white smoke, zero coolant or oil loss. When I accelerate the smoke is blackish maybe even whitish, sometimes I start it and it does a huge puff sometimes it barely does any. One time I was sitting at a red light and accelerated and I saw a good amount of white smoke, another time none. Do I need a engine? Is a connecting rod maybe bent?

Oh and when the car is cold the smoke is white, when its fully warmed up it turns Blackish but I belive it fades off to a whitish color.

 

[Diesel Fumes]

Ok heres a update, every time I start the car weather it's hot or cold I am getting a big puff of white smoke, zero coolant or oil loss. When I accelerate the smoke is blackish maybe even whitish, sometimes I start it and it does a huge puff sometimes it barely does any. One time I was sitting at a red light and accelerated and I saw a good amount of white smoke, another time none. Do I need a engine? Is a connecting rod maybe bent?

If it starts, runs, drives and stops then keep doing what you're doing. As I've told you my tdi does this all the time. I recently bought a second and its also smokes upon start up if its sat for a while especially. But besides polluting the environment slightly every time I start them, they are behaving normally

 

[Gothmolly]

I've aways heard :
white smoke = water
black smoke = fuel
blue smoke = oil