Engine still running after keys remove from ignition - 2008 Audi A3 1.9 TDi

[Pies]

A couple of weeks ago I bought a 2008 1.9 TDi Audi A3 but I'm having some issues with it. Before handing over the money I did all the usual checks and everything seemed in order along with taking it for a 15min test drive (I pushed the engine quite hard and there was no black smoke) or any sign of any problems.

Whilst I was driving home the car lost power and started making a whooshing noise. Luckily I was only around 5 mins from home and managed to coast back and use the engine as little as possible.

I got under the car as soon as I got back and noticed an air intake pipe had come off. A friend came round to have a look and said the pipe had just come unclipped and fixed the problem, but he did say it looked like there was an excess of oil in the pipe and the clip had been put on backwards. This made me a little suspicious that someone may have previously taken the clip off to clean out the intake to hide any engine problems. My friend told me to take the car to a garage and to get it checked over for peice of mind.

The next day the car drove fine but I noticed an oil leak coming from the air pipe so I booked it into the garage. Last week the garage said it just needed a new intake pipe and the seals replacing to fix the oil leak which they did.

Over the the past few days I've noticed there is still a slight oil leak from the air pipe and on 3 separate occasions the engine has carried on running when I've taken the keys out of the ignition. The engine carries on running for between 5-10 seconds before it slowly dies down.

I'm struggling to identify what the problem is as the garage said they'd checked the engine last week and everything is in order. I'm worried that this is going to be a serious problem as the car is quite high mileage at just under 160k and I've spent over £500 on it over the past week so I don't want to carry on throwing money at a sinking ship.

Has anyone else had this problem in the past?

[zollaf]

did you buy from a garage or privately.

[Pies]

I bought privately but I'm suspicious the guy may have been a trader as he mentioned he had trade plates.

[zollaf]

ok, so the engine could be starting to run on its own oil thats bypassing the turbo. if he is a trdaer then i would go back to him and ask him to sort it out or give you a refund. its easy to tell a ttrader from a genuine private seller, just find out how many cars they sell. oh, but only a trader will have trade plates, so he is a trader posing as private to save on warranties, so first port of call would be the threat of going to trading standards.

[zollaf]

trade plates come at a price with a motor trade policy. if he is not a trader then he is fraudulently obtaining insurance allowing him to drive any car that is un taxed, no mot etc, for which he would get into big trouble, or he is a dodgy trader posing as a private seller, either way, hes >>>>>>

[Pies]

The seller is on holiday at the moment, so I've booked the car into the garage to get a diagnosis and cost to get everything repaired. I found another fault today, the DIS doesn't seem to be working properly as the average speed is constantly stuck on 17mph and the average mpg doesn't seem to be anywhere near right.

Once I've got some costs tomorrow and know everything that is wrong with the car I'll be contacting the seller with a list of all the faults and asking him to cover the cost of the repairs otherwise I'll have to take things further. I've just checked the previous owner on the log book and it's a different name and address to the seller so I'm convinced he's a trader posing as a private seller.

[NHN]

Oil around the intake pipes is perfectly normal, that's not really an issue tbh, so I wouldn't worry unless its pouring like a river.

Overrun could be the intake manifold flap faulty not shutting of the air & also could be a faulty ignition barrel.

Reset the average speed via the wiper stalk button & drive again & see what it does.

[zollaf]

the flap shuts to stop the air if and when the engine is running away on its own oil. take the flap away and the engine will still stop as normal.

[Pies]

Thanks for all the replies. I reset the computer last night and that all seems to be ok now so that's one problem ticked off the list.

There isn't a river of oil coming from the intake but there is enough to cause a small oil leak.

I've just dropped it into the garage so hopefully I'll know what the damage is going to be in the next couple of hours and then I can get onto getting it resolved with the seller.