ESP warning Light

[paulfieldhouse]

The ESP warning light appears when the car is cold on my 121k mileage 02 reg A6 Avant 2.5TDI - any thoughts on resolving without big cost.
New discs & pads recently fitted

[Martin Burnard]

Same problem on my 130 TDI, it aslo runs lumpy. If I wait a few minutes for engine to warm up, turm off engine, restart, it runs as it should!
Any body out there have any ideas?

(Will go and post an intro to say hello!)

[paulfieldhouse]

Thanks Martin - car is running well at present. Very occasional high idling revs recently.

[Martin Burnard]

I will keep you all informed as I progress with this...... so here goes.

The car has been sat doing nothiing since 7 November 2007, now bought by me in a burst of foolishness. So damp penetration is a possible.

The poor running and ESP light are definitely affected by the engine temperature (or it's a consistent coincident).

In the past we had a similiar problem with a skoda diesel (3 cylinder) and it turned out to be the electrical connections around the injectors (diagnostic warning here..... VAG said it was one of the injectors needed replacing). So as soon as Dave (the retired mechanic who should also know better then to get involved with cars) is out of hospital (who needs eyes?:p), we will start the "clean all electrical contacts and sensors" approach.

[Martin Burnard]

Ok More info

Just recieved the service history.

The rear brake pads were replaced just before (literally just before) the car was stood up. So first port of call this morning is to check the sensors on and around the rear wheels, clean them check thier seating etc.

[Martin Burnard]

Ok nothing obviously amiss at the rear, so pull off electrical connections under the bonnet, spray with electrical contact cleaner and refit.

The car has started just fine...... need to do this a few more times whilst not letting the engine warm up, repeat tommorrow morning and then we will know!

[Martin Burnard]

Joy short lived, problem is still there.

[Martin Burnard]

Ok now we have taken the rocker cover off and had a look at the electrical connections for the injectors. We cannot see how to unplug them so have cleaned out the oil around them, sprayed them with electrical cleaner, wriggled them about, put the rocker cover on and..............
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All runs smoothly, know all we have to do is wait again and see what happens when started up again later!

[Martin Burnard]

Fired it up just before leaving tonight.......... all is good.

Hopefully same result in the morning.

[Martin Burnard]

Oh Bother!

Started fine first thing, drove it 2 miles and it started to miss on 1 cylinder again.

So popped in for a diagnostic (snapon kit), showed intermitant electrical fault on injector number 1.

So off with the rocker cover again.

Now I hadn't mentioned that last time we could not see how to get the injector connections off, local audi dealers gave us some help but it didn't tie up with what I was looking at. Anyway much looking, and more looking, revealed the answer, there is a little square hole, just in sight, get a pick in there, and gently ease the connector off. So blow out all the oil with an air line, douse it in electrical contact cleaner, and leave alone whilst we have lunch. After lunch we will tighten up the connections, refit and fire up.

Martin

[Martin Burnard]

OK all done, and the car has started like a dream, sounds like a sewing machine (or at leats what I think a sewing machine would sound like!), it has been driven to get it warm, and runs superbly.

Now we wait to repeat the process in the morning.

Hope people are finding this useful!

Martin

[Martin Burnard]

Ok good news

The vehicle was started this morning whilst covered in ice, all running beautifully, it has been started again, since and runs like a dream. Marvelous!

Monday it goes for sale.