TDi rough starting with smoke..

after fitting new plugs did u notice if light stayed on longer than it did , I had an issue with smokey start up as it was turning over a few times there was unburnt diesel causing smoke , anyway I tested glowplugs with meter all 3 open circuit so replaced , after replacement problem solved and noticed glow light stayed on longer as a result of working plugs , as previously stated there are different plugs for the a2 depending on age and model and are colour coded plugs at the insulator , I ordered bosch plugs using vin number as reference as wasn't sure if old plugs were correct as all three open circuit
 
Just checked on another couple of sites, and it may be that the 90HP had the 5V, and the others the 11v. I did notice that the ones I removed had a different colour band than the ones I replaced them with.
And to top it off, you can get a 'full' or 'short' version of the 11v ones (although they also specify the heater tube length, which is 29mm for both
 
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allypug said:
Just checked on another couple of sites, and it may be that the 90HP had the 5V, and the others the 11v. I did notice that the ones I removed had a different colour band than the ones I replaced them with.
And to top it off, you can get a 'full' or 'short' version of the 11v ones (although they also specify the heater tube length, which is 29mm for both
Click to expand...
Checked the old ones last night, they are OE BERU ones, N10579202, and are indeed the 11v ones. Hopefully I'll get a refund as Eurocarparts spec'd the wrong ones for my car!!??
 
allypug said:
Checked the old ones last night, they are OE BERU ones, N10579202, and are indeed the 11v ones. Hopefully I'll get a refund as Eurocarparts spec'd the wrong ones for my car!!??
Click to expand...
Oh FFS! Just changed the plugs for the correct 11v ones, and still the same.. but now I can't hear/feel the relay clicking. So fitting the wrong voltage plugs can kill the relay?
 
allypug said:
Oh FFS! Just changed the plugs for the correct 11v ones, and still the same.. but now I can't hear/feel the relay clicking. So fitting the wrong voltage plugs can kill the relay?
Click to expand...

Yes, possibly because there would have been a lot more (too much?) current going through it.

RAB
 
If your smoking issues persist, have you had a compression test?
I had the same symptoms on mine after much changing of the usual suspects mine was found to be low in cylinder 2.
Vince at stealth, after my head scratching traced to broken piston ring. Only spotted after removal as bore scope and head removal showed no damage.
Jonathan
 
vkx245l said:
If your smoking issues persist, have you had a compression test?
I had the same symptoms on mine after much changing of the usual suspects mine was found to be low in cylinder 2.
Vince at stealth, after my head scratching traced to broken piston ring. Only spotted after removal as bore scope and head removal showed no damage.
Jonathan
Click to expand...
Touch wood it's not that! pretty sure its now a relay as its not clicking
 
Have you checked the 60A fuse which is right by the relay, at least for the AMF engine version? I'd be a bit surprised if it survived the overload.
Matt
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Oh well, though I had it fixed after fitting a replacement relay.. worked on first start after fitting. Not since then!!
Gonna check the wiring next as I've had a bit of loom destroy itself in the brake pad sensor section before.
 
Checked voltages the other day, a tiny voltage is getting to the glowplugs, something like 0.5v, glowplug lamp in dash works, so the relay works, looks like failed wiring somewhere along the loom! Bollox!!
 
I would replace the relay first. If the relay contact is burnt (as it might be if the current passing through it is too high), its resistance will have increased.

RAB
 
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RAB said:
I would repace the relay first. If the relay contact is burnt (as it might be if the current passing through it is too high), its resistance will have increased.

RAB
Click to expand...

Agreed, perhaps trying measuring resistance first and then if at all suspicious take it apart for a look. I presume a new part is expensive, so perhaps borrowing a known good one would be worth a try.

Incidentally, I'm not that far from you on weekdays (Stevenage) and I have a TDi90 in my garage going nowhere ...
 
Checked relay, and the spare ebay one, both work fine, took the spare apart, no signs of burning. Checked voltages, and they pass on the 12v fine. I suppose I could get replacement glowplug leads and bypass the loom, going direct from the relay?
 
Ok, so still have the glowplugs not working..
glowplugs are good,
relay is new Audi,
Big fuse is fine,
Wiring from relay to plugs is fine,
12v is read at relay contacts to the plugs.

What I'm now thinking is that the relay isn't being 'energised' (switching)
Is there a control unit somewhere that controls this?
I'm going to rig a manual switch instead of the relay and see if that works!
 
vkx245l said:
If your smoking issues persist, have you had a compression test?
I had the same symptoms on mine after much changing of the usual suspects mine was found to be low in cylinder 2.
Vince at stealth, after my head scratching traced to broken piston ring. Only spotted after removal as bore scope and head removal showed no damage.
Jonathan
Click to expand...
Hi Jonathan, After much changing electrical bits here and there with no improvement, I did a compression test at the weekend... looks like you were right all along.. suspected piston ring failure, readings were 33,34,10 (bar), with a bit of oil squirted in bore 3, it went up to 15 bar.
Could I ask how much did the repair work cost on yours?
Will probably do it myself, but if it's not too horrendous I may splash the cash instead.
cheers
Steve T
 
allypug said:
Hi Jonathan, After much changing electrical bits here and there with no improvement, I did a compression test at the weekend... looks like you were right all along.. suspected piston ring failure, readings were 33,34,10 (bar), with a bit of oil squirted in bore 3, it went up to 15 bar.
Could I ask how much did the repair work cost on yours?
Will probably do it myself, but if it's not too horrendous I may splash the cash instead.
cheers
Steve T
Click to expand...

Hi Steve
Apologies for the tardy response.
It will depend on the extent of any damage, if the piston ring has failed and scored the liner.
Alot of the cost I incurred was diagnosis but I was fortunate that the bore was clear when stripped down. Unfortunately the disassembly of the bottom of the engine adds to the parts bill as new shells etc should be used on reassembly. I'll try and find the bill if it will still help, it might provide a ballpark for the parts.
Cheers
Jonathan
 
Was this sorted in the end? Sounds similar to the problems I had with my 1.4 75bhp TDI (AMF) which tipped the balance and prompted me to say goodbye to it. I wrote it up here https://www.a2oc.net/community/inde...moke-when-starting-from-cold-in-winter.36279/
I had an additional clue at the time that I disregarded - my dashboard temperature gauge misbehaved, intermittently. I wish now I had tried replacing the coolant temperature sensor. Suspect the two problems were linked because the coolant temperature sensor is 4-pin type that feeds separate temperature signals to the dashboard guage and to the ECU. This definitely was the problem in my 1.4 petrol, but different symptoms (part-time dash gauge, intermittent not starting when engine warm, replaced sensor both problems gone).
 
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