2007 A4 B7 2.0 TDI Cabriolet - Starting Issues

[Springer*]

Hi there,

My wife's 2007 Audi A4 B7 2.0 TDI S-Line Cabriolet has recently developed starting issues.

Seems to affect the car mostly when completely cold (i.e. first thing on a morning) and the starter turns over fine, but it can take anything up to 30 seconds for the engine to begin to splutter into life.

Once the car starts, the engine runs perfectly smoothly and drives fine.

The car has high mileage (just over 182k) and all servicing is up to date and as it should be. I recently had the EGR and intake manifold completely stripped down and de-sludged too, so they are working perfectly.

Could anyone shed any light on what it might be, or has anyone had similar issues?

I'm thinking that the fuel pump is okay given that it runs fine once started. The starter seems fine too and the engine isn't sludged up any more. All hoses and air filter seem to be perfectly fine and the fuel filter was changed maybe 12 months ago too.

I'm thinking possibly glow plugs, given the age/mileage..?

Any ideas would be a great help.

J

 

[NHN]

Once started, does it start perfectly afterwards & then a long non use the issue happens again?

 

[Springer*]

Once started, does it start perfectly afterwards & then a long non use the issue happens again?

Yes, that's exactly what it does.

J

 

[rob_t]

Once started, does it start perfectly afterwards & then a long non use the issue happens again?

I’m having this exact same problem, slow to start after it’s been sat overnight but it’ll be fine for the rest of the day. Replaced the battery a little over 6 months ago with a Bosch so that shouldn’t be a problem, not sure what to check next, any ideas?


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[NHN]

Unplug the coolant sensor & see if this makes any difference.

 

[Tiprat]

That's an interesting suggestion, could you explain the reason behind it, I'm having the same problems, so I shall unplug it on mine to see if it cures it.

 

[NHN]

Seen it where it reads wrong & adjusts fuelling wrongly based on wrong temp read, A3 8P suffered this on some engines, worth a go.

It usually was ok on restarts.

 

[BakPak]

Every day is indeed a school day.

 

[NHN]

Totally agree with that.

 

[Springer*]

Interesting idea this. Could you tell me where the coolant sensor is located?

Not sure why this would stop the car from starting when cold though. Wouldn't this just cause it to over-fuel if the coolant sensor was misreading?

J

 

[NHN]

Exactly, over fuelling would cause starting issues afaik, I'm not a full on mechanic but logic denotes iirc

Don't know the engine code bud, so I wouldn't know where it is, Google