Hi all,
I've got another post going on with with the first symptoms and they came back with a few ideas. I've been playing and now the cars gone nuts.
Initally I was geting a small amount of white smoke (diesel smelling, not oil / or coolant) when starting from cold. Yesterday i was playing with the vacuum hose system (replacing them to try and fix an underboost problem)
Now the car is consantly putting out the white smoke especially when accelerating. When I say white smoke - it is pure white smoke and smells strongly of diesel, and there is loads of it (enough to envelope the car) - for those who want to see a Tdi blowing smoke here's a link to my vid.
www.youtube.com/watch?v=RBgCa__sQoc
I've read the posts on head gaskets, etc and I don't think it thats, this has only got worse since I played with the vacuum and air system.
For reference the car is a 2002 passat 1.9TDI AWX engine code.
Any ideas? Have I missed something when connecting it all back up??
thanks
Richard
Edited by Webmaster on 15/06/2008 at 20:05
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itseems to disperse pretty quickly for smoke, sure it's not steam?
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Hi,
If its steam I would expect it stop once the engine is warm / hot. At this stage I'm not ruling anything out but where would the water be coming from? And why the smell of diesel.
All levels are fine under the hood from what I can see. I'm pretty sure I've suffed up somewhere on the hoses / vacuum pipes but can't find a diagram anywhere.
cheers
Richard
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Richard
If that is smoke; then it would trail about 50-100 yards down the road and leave a huge black patch under the tailpipe - does it?
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Hmmm, in that case it might not be smoke.
Theres no patch under the exhust and the 'smoke' disperses around the edge of my garden - so 20 feet away.
That throws me back to what else could it be? I'm not noticing any level change under the bonnet (although I'm not monitoring that closely.) I'll mark off the coolant tonight and take it for a drive see if moves any.
Any over thoughts as to where it might come from? and why it would get worse after my playing with the vacuum lines?
cheers
RG
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Richard
As I said before [why are we on two threads?] you have two problems - did you get that compression test done?
If that's steam; then i'm thinking head gasket and coolant-soaked exhaust.
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Hi,
thanks. I thought it made sense to seperate the two problems onto seperate threads. Avoid confusing myself.
its booked in on wednesday for the test, so hopefully that will help.
cheers
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Maybe it is fuel vapour. Diesel trucks (especially Rolls Royce engines) used to bellow white smoke like this for the first couple of minutes until firing on all 12 cylinders. I think you may not have enough compression on one cyclinder to fire the diesel, so it just gets vapourised and emitted from the exhaust. Can you light this vapour with a blowtorch?
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is your car using coolant , ie-is the expansion tank draining ? if not , and the smoke smells of unburnt diesel , its most likely overfueling , why is difficult to tell , it could be a number of things , coolant temp sensor , air mass meter , ecu , does it dissapear when warm ? or at least deminish ?
personaly , i would try vacum hoses 1st , there is a small hose which i think goes to a pneumatic vacum switch from the turbo when its on boost to tell the ecu to increase fuel delivery on and during boost . if you have inadvertantly connected this to a permanent vacuum the ecu will be shovelling fuel in at an incredible rate , the balance of fuel and air will be offset , and lots of unburnt fuel will be chucked out as white fuel vapour.
i hope im right mate and you can sort your car , ive got a passat diesel and i,m chuffed to bits with it , all the best
Richie
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thanks all,
the coolant level hasn't moved. Sounds like I mixed up the vacum pips (maybe) - anyone know of a vacum pipe diagram for a 1.9tdi 2002 awx engine?
thanks
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Richard, I can't agree with your approach to this problem and the randomised pulling of pipes on which is a fairly sophisticated power unit is unlikely to give good results.
However I would always wish to be positive and on page 4C.4 of the Haynes manual 4279 for the PD engined Passat there is such a diagram. Of course, it wouldn't be genuine Haynes if it were accurate so here are the errors I've found:
Item 4 - VNT actuator. Item 5 - Non return valve. Item 11 - VNT control valve (N75).
Again, without being disparaging in any way, I'm not going to attempt a diagnosis with the facts and strategies already established and followed. However, for your own safety, check the brake fluid level.
The vac part of the tandem pump exhausts into the crankcase whose blowby appears in the inlet via the breather hose teed into the compressor inlet. If there is a servo fault (possibly caused by a rusty vac housing due to blocked plenum drains) the brake fluid will be sucked into the crankcase. Only a very little brake fluid at the engine intake will produce voluminous white smoke.
Best of luck - don't be afraid to seek informed help.
659.
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659 - thanks for the info. I was already playing with the pipes to try and resolve my under boost issue. I just to check taht I put them all back the correct way. Didn't see it in the hynes but found it now.
cheers for the help, hopefully it was something silly.
cheers
BTW - whats with the number? you with the job?
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ok I've checked the wiring of the vacuum hoses. All correct.
I took the car out for a spin - still no power for overtaking. turbo kicking in around 3000 revs. Still lots of smoke under accleration.
I had a mad moment and decided to try the blow torch idea - the vapour does ignite. its definately fuel vapour.
I've vag com on way so hopefully that will have more idea whts wrong!
thanks for all your help thou.
RG
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Hi all.
I finally got a cable and shareware copy of vag-com. I've hooked it this morning and taken a load of readings from groups 001 - 025 at both idle and 3000 revs. Got tons of results but not too sure which areas I should be looking at.
Also the car has developed another fault code since I played with it the other day. I'm pretty sure thats whats causing the exessive smoking.
The faults as reported now are:
17964 - p1556 - Charge Pressure Contr. Negative Deviation
17552 - p1144 - Mass or Volume Air Flow Circ Open/Short to Ground
I'm assuming the second one is causing the white smoke on accerlation?? not enough air getting into the mix so the car throws out the fuel vapor - or does it not affect it that way?
Lastly I saw the group that showed glow plugs, with engine off but igination on I had two of the digits showing 1 (off) and all the others as 0. After the engine started they all went to 1. Am I assuming that this means I have two plugs out?
If anyone is interested in the figures vag-com throw out I'll paste them, if you let me know which groups (001 - 025)
If you actualy wnat to see the smoke and sick engine noise:
www.youtube.com/watch?v=RBgCa__sQoc
thanks
Richard
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Forgive me for asking again if I've missed it; but did you get that compression test done?
Edited by Screwloose on 21/06/2008 at 17:31
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Hi
sorry forgot to update with that result - according to the dealers the compression test was fine, not sure if I believe them thou... especially with vag-com showin those two 1's on the glowplug test....
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Screwloose - leaving the possiblity of a bad test I've followed the instructions on the vag-com site for testing MAF and turbo. Basically it take the car out put it in 4th. Floor the gas at 2000 revs up to 4000 revs. Problem was the car wouldn't get to 4000 revs!! However heres what I found so far:
Block 003 recording in graph format:
www.traceyourfamily.co.uk/block003.jpg
Block 011 recording in graph format:
www.traceyourfamily.co.uk/block011.jpg
I guess the MAf is stuffed ... any other thoughts?
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Richard
Hard data - that's what I like to see.
Right; you have negligible boost [so that's the 17964 code] and the intake volume is being measured as far below target mass.
Either the turbo is totally non-functional; or there is some restriction on the passage of gases - try it with air filter removed.
Does this one have a "diesel cat" in the exhaust?
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Hi,
The air filter was replaced recently by the garage - I'll pull it out and see what its like without it.
I just read a post about blocks 115 and 118 - will that data help any more or is there enough above?
Not sure about the cat - I'll check it out when the rain stops here (probably never it continously rains!)
thanks
RG
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Screwloose -
I finally worked out a way to do the test on the actuator. I tried sucking on the pipe direct to the actuator, it didn't budge. Although the rod itself moves quite freely.
Not having a pump I came up with the idea of modifing the vacuum cleaner at home - hooked the cable up that I was sucking on and turned the hoover on. The rod moved, a good few mill up turned the hoover off and it went back down. Did it a few times.
I then tried sucking on the tube and this time the rod moved - did it a couple of times just to make sure I wasn't imagining it!
I hooked everything back up and turned the car on - the rod didn't move at all. Tried vag-com on the output tests - still no luck.
I'm guessing from this that the actuator part is okay, and that its whatever controls the vacuum / pipe to the actuator that might be at fault...??
I took the car out and it seemed no different. Still no boost / power. So I pulled over and turned off, then I decide to clear the code off the car and take it out it again.
Immediately the car felt better, there was more power and pull. I had vag-com running and it hit 1800 odd on the block 11 whilst I was acceleration through the gears. then it shut down and no matter how much throttle I gave it it wouldn't go above 1180 for block 11.
I have the new readings in graph format if anyone wants them, but I guess they are the same as above.
I'll remove the air filter and take her for a spin tomorrow see if theres any difference.
Any thoughts which part to look at next? i was thinking of replacing all the small hoses to/from the N75 and turbo. Anyone know which size / spec of tubing I need and palce in the UK that sells it?
or would you go striaght for the n75 as faulty part for the boost issue...?
I'm still sure the compresion test result was bogus and that I have a compression problem casing that fuel vapour / white smoke issue.
thanks everyone, think I'm getting closer now.
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I know nothing about mechanics, but my old Rover had identical symptoms to yours - does the turbo come in abruptly? Mine was a sticking EGR valve or solenoid ( never fixed, just disconnected ). Mine did the smoke and no power just like yours.
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Me too, I have a Passat with a different engine, and shortly after I bought there was a sticking EGR, this gave a low MAF reading because unmetered gases from the EGR were going into the engine, and it just choked itself on smoke.
www.honestjohn.co.uk/forum/post/index.htm?v=e&t=42...3
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Hi all, thanks for the help with this problem.
Had a second compression test done and it came back fine.
Today I gave the car a full 10k service (filters, oil change etc) and replaced all small (3mm) hoses on the car. Started it and first thing to note is there's no white smoke!! not even a bad smell.... - no idea why or what part fixed it but its gone for now.
However thats where the luck ended - I still have no boost. The VNT rod does move under an external vacuum (me sucking very hard through a pipe) but it doesn't budge on the output tests or ignition. I don't have a vacuum gauge and nowhere road here seems to have them (deepest darkest part of Ireland)
At least I can rule out the small vacuum hoses, might do the large ones next. I'm thinking that I might have a punt and just order a new MAF and wastegate / turbo pressure unit (110 gbp all in from local vw garage) and see what happens....
any thoughts?
I logged the data for the drive today in case anyone else as other thoughts. thanks everyone again.
www.traceyourfamily.co.uk/raw.jpg
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Richard
Have you tried an old-fashioned garage for a vacuum gauge - they were a common tool in the days of carburettors?
Have you tried bridging-out the N75 valve?
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Something I remember from the Galaxy website with the VW 1.9 TDi, a member who had a problems similar to MAF failure found there was another MAF type sensor further down the induction path - could it be a TMAP sensor ? Sorry to be vague -it might jog someones memory.
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Hi Screwloose - I'm just browsing the web/ebay o find one, hopefully not too expensive. Ireland is useless for car kit / parts.
I read about bridging the n75 but the post didn't really explin the procedure - can you clarify what needs doing?
thanks
Richard
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Richard
Pull the two vacuum pipe off and join them with a bit of tube - brake pipe suffices. Just for a quick test.
Fleabay has a "diagnostic tools" section.
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Is the lack of boost just a blown off/disconnected intercooler pipe?
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