A2 TDi 75 160k miles, smokey on cold start. Is it normal?

philward

Member
When you check / change the battery it is very important that the battery terminals are clean, the leads are firmly clamped onto the terminals and the little black block to the left of the positive terminal is tightly bolted to the positive clamp and all the internal connections inside the block are tight. Be careful not to short these to earth while tightening them!!! The other often problematic lead is the starter to body earth just below the ABS pump / left head light, not only can it be loose, but can often be corroded internally so just checking it is tight is not enough. Many of us run a secondary body to engine earth as an insurance. Glow plugs do fail but it is obvious the car is only running on 2 cylinder when that happens, but if there power supply is too low they are not getting hot enough to warm the cylinder to burn all the fuel. When the engine is warm the glow plugs are not required and the engine will start with no or far less white smoke.

Strangely enough the one earth lead I would have though to cause more problems does not appear to be causing any. That is the one that runs from the battery negative post to the chassis just in front of the left rear wheel.
Battery appears very good. Prime suspect is an earth strap.
 

philward

Member
I think I have found it, 8Z0971237K


gO2pe2n.jpg
 

audifan

A2OC Donor
Yes that is the starter to chassis earth. BUT even if you try to change it there is a chance the bolt into the chassis will shear off as you try to remove it. For that reason I suggest 2 things to do. Order an earth lead about 6 inches longer than the original one, then connect that one to the starter and to the gearbox mount making sure you connect to the chassis side and not the gearbox for best earthing. Second run a secondary earth on the opposite end of the engine between one of the tensioner bolts on the engine and to the chassis side of the engine mount routing the lead well away from the belts and alternator.
 

philward

Member
What a job; a cable tie, one bolt and one nut took me 3 hours! Main problem was the bolt to the space frame, solid with a white powder. I assume the white powder is salt but I don’t see it on steel cars so perhaps it is aluminium oxide?
Was so cold by the time I finished I didn’t bother trying to start. Fingers crossed for a less smokey start this morning 🤞
 

philward

Member
What a job; a cable tie, one bolt and one nut took me 3 hours! Main problem was the bolt to the space frame, solid with a white powder. I assume the white powder is salt but I don’t see it on steel cars so perhaps it is aluminium oxide?
Was so cold by the time I finished I didn’t bother trying to start. Fingers crossed for a less smokey start this morning 🤞

Well if it is aluminium oxide that collects in the steel threads, see link, I shouldn't be surprised by the number of aluminium female treads that I've stripped out on my car and had to coil or replace the component.
Yesterday it was difficult to clean the bolt with a wire wheel and the female tread was very reluctant to accept a tap. Car friskier on start but still smokey this morning. Could be left over fuel from the last cold start; only drove 15 metres.

 

philward

Member
Found some of these white deposits on a steel car. A 1989 Golf, built to last, has thick aluminium washers attached to heat shield location points. Prevents the heat shields dropping off as on an A2. The golfs 30 year old heat shield washers are absolutely covered in white deposits. They don't clean easily with abrasives and I’ve had to take to acid dipping to remove the oxide. The aluminium castings unlike an A2 were coiled at the factory. So I have no issues with bolts breaking or thread damage on the golf.
Coming back to this repair I’ve opened up the old earth strap and can’t find a fault. I suspect my poor starting was caused by aluminium corrosion at the earth point.
 
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philward

Member
The engine is turning over better but still producing lots of smoke on cold start. Felt like is started on two cylinders yesterday. Switching my attention to glow plugs.
Is there no warning light for glow plug failure on an A2?
 

Howey

Member
The engine is turning over better but still producing lots of smoke on cold start. Felt like is started on two cylinders yesterday. Switching my attention to glow plugs.
Is there no warning light for glow plug failure on an A2?
No i dont think so was later on when they became tied into engine management i know i can unplug mine on the 2005 galaxy 1.9 pd and start the car and no faults are shown or recorded in ecu
 

kp 115

Member
The engine is turning over better but still producing lots of smoke on cold start. Felt like is started on two cylinders yesterday. Switching my attention to glow plugs.
Is there no warning light for glow plug failure on an A2?
Hi Philward,
Treated mine to a new set from darkside developments @ 246,000 miles they were around £10 each against £20+ from TPS
Hth
Keith.
 

depronman

Member
The engine is turning over better but still producing lots of smoke on cold start. Felt like is started on two cylinders yesterday. Switching my attention to glow plugs.
Is there no warning light for glow plug failure on an A2?
no monitoring of the glowplugs by ecu on the A2 easy to test with a jump lead though they draw a fair current
test each one with the jump lead you will get a sparl as the jump lead powers up the glowplug
Paul
 

philward

Member
First cold start this morning with new plugs; started instantly with no smoke at all 👍

Thanks all for your help and advice, slow cranking was caused by corrosion of the engine earth connection point on the space frame and the smoke was the result of at least two glow plugs having failed.
 

kp 115

Member
First cold start this morning with new plugs; started instantly with no smoke at all 👍

Thanks all for your help and advice, slow cranking was caused by corrosion of the engine earth connection point on the space frame and the smoke was the result of at least two glow plugs having failed.
Hi Philward,
Have you any idea how old they are ?
I’ve got mine to change this weekend.
Thanks
Keith.
 

philward

Member
Hi Philward,
Have you any idea how old they are ?
I’ve got mine to change this weekend.
Thanks
Keith.
I think they have done about 80k miles, only ever changed them once and owned the car from new.

I'll take a look at my service book and see if I recorded the change. The info may not help you though, see my next post.
 

philward

Member
I retrieved my old plugs from the scrap box to see if they had a manufactured date on them. That way I could advise kp 115 the miles they have driven.

One of them looks like it exploded, hopefully the bits will be long gone.

IMG_6614 (2).JPG


While looking for a date of manufacture I noticed that the plugs are marked 5V:

IMG_6617 (2).JPG


Have I been driving around with TDi 90 plugs in a TDi 75? I thought this combination melted piston crowns?

Edit, indeed I have, Beru 0 100 266 008 are 5V plugs. Car runs fine; what damage is likely to have occurred?
 
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kp 115

Member
I retrieved my old plugs from the scrap box to see if they had a manufactured date on them. That way I could advise kp 115 the miles they have done.

One of them looks like it exploded, hopefully the bits will be long gone.

View attachment 76476

While looking for a date of manufacture I noticed that the plugs are marked 5V:

View attachment 76477

Have I been driving around with TDi 90 plugs in a TDi 75? I thought this combination melted piston crowns?

Edit, indeed I have, Beru 0 100 266 008 are 5V plugs. Car runs fine; what damage is likely to have occurred?
I retrieved my old plugs from the scrap box to see if they had a manufactured date on them. That way I could advise kp 115 the miles they have done.

One of them looks like it exploded, hopefully the bits will be long gone.

View attachment 76476

While looking for a date of manufacture I noticed that the plugs are marked 5V:

View attachment 76477

Have I been driving around with TDi 90 plugs in a TDi 75? I thought this combination melted piston crowns?

Edit, indeed I have, Beru 0 100 266 008 are 5V plugs. Car runs fine; what damage is likely to have occurred?
Hi Phil,
I had to give Darkside developments the Reg to ensure I got the right ones so hopefully my installed original ones are factory fit🤞they were ok at 197,000 miles when the cambelt went
I just gave them a clean & reinstalled all was ok until this recent cold spell
so I treated it to a new set & have got a new injector loom just incase.
thanks
Keith.
 

spike

Member
You've been lucky Phil
A couple of members reported that fitting the 90 tdi low voltage glow plugs into a 75 tdi engine resulted in the tips falling off causing serious engine damage


Cheers Spike
 
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