2.0 tdi sport struggling to start

[JayCho]

Hi,

I've started to have real issues with my tdi sport in the last month or so. 

 

When I havent driven for a couple of days, it really struggles to start, normally takes 2-3 goes to turn over. 

Had this problem earlier in the year and I had the battery replaced and this seemed to solve the problem. A month ago the problem started again and had the starter motor replaced but it seems to have come back again!! 

 

I dont know much about cars but it seems there may be another issue aside from the battery and starter motor? 

Any ideas? 

Thanks 

[cliffcoggin]

Jay. Are you saying it is reluctant to turn over, or it turns over well but is reluctant to fire?

[JayCho]

7 minutes ago, cliffcoggin said:

Jay. Are you saying it is reluctant to turn over, or it turns over well but is reluctant to fire?

Hi Cliff, it is turning over but is reluctant to fire 

[cliffcoggin]

Jay. In that case the starter and battery have nothing to do with the problem.  Without far more detail one can only speculate about the cause. For the engine to fire it needs three things:

[1] Compression. Are the valves or rings worn? A compression test would give you the answer.

[2] Fuel. Has the fuel filter been changed recently? Is the pump delivering enough pressure? Are the injectors working properly?

[3] Air. Has the air filter been changed recently?

[Magnet]

Hello Jay,

I don't want to undo what I think Cliff has rightly advised, but I would question excluding the battery and starter motor simply because they were repalced last year - although appreciating that it's "turning over" as you say. Question is:- how enthusiastically? 

We don't yet know how enthusiastically this is turning over,  and although probably less critical than with petrol engines, I guess this is still a valid point. Pardon my explanation, but there is some really smelly stuff on the market in terms of batteries, and even more so with replacement starter motors! A voltage check under starter motor load/operation may be a good place to start. 

I feel Cliff's suggestions under (2) and indeed (3) are really where you want to be checking after ensuring the battery/starter motor components are on song. All other things being equal, it might be worth checking the fuel pump relay (those more knowledgeable on diesels will perhaps offer better advice). 

Fault code reading would then probably be useful, although being old fashioned!, I sometime feel these are taken as the be all and end all of diagnostics, when sometimes the cause-and-effect aspects of the existence of these codes can sometimes be overlooked. 

If all else fails, then I would be treating this to a half day out with a local trusted diesel specialist rather than an Audi dealer or independent.

Kind regards,

Gareth.