A6 2000 2.7t - won't start when engine semi warm

[dan small]

I have a 2000 2.7t with 80k on the clock. It has an intermittant problem with starting. If I drive the car so it's warm, stop the engine, then try and start it after 10 mins, it just turns over but won't start. Try 10 odd times and it just won't start. Leave it for ten mins and it will then start up (although it struggles a bit).

Let it tick over for a few seconds and switch it off. It'll then start up fine, first time!! This only happens intermittantly and not when the engine is cold (at least not up until now). Any ideas cos it's starting to get me down and I really like the car otherwise?

 

[simonwjones]

thinking outloud here, but it could be the temperature sensor.


Simon

 

[red-sport]

I have a similar problem with my 2003 A3 2.0FSi. Anyone know if it is the temperature sensor? Starts from cold fine but as soon as the engine is warm it will take 3 or more turns to fire and runs lumpy for a second or two. I had 3 fault codes recently, the camshaft position sensor, the oxygen sensor and something else. Replaced the cheapest (camshaft sensor) but problem still persists. Hope it isn't the Ox sensor because they're £500+!!! Recent work has included: new rad, water pump and cam-belt. There are no service lights on the dash. Any advice appreciated before I go back to the garage. Cheers

 

[mrnice]

A long shot but crank sensor maybe?, afaik it's only used as a ref during starting and idling?, might not throw a fault code either?

 

[red-sport]

Thanks mate. I'm going to get a VW-Audi diagnostic check to see if they can tell me for sure.

 

[red-sport]

Just to clarify, the problem with starting when warm/hot always resolves itself in the same way. On the third turn of the key the engine will fire, run lumpy for a 2-3 seconds then settles down.