Hi guys I have a 2006 A4 estate,diesel by mistake I accidentally put petrol in 10 ltrs, not a great idea 

, I tried getting a fuel assist company out nobody in area AA woulnt recover me to Newcastle was in Scottish Borders, as they then said I hadn’t technically broken down 😳as I hadn’t started the car, thought poor service for a young girl late in evening.

anyway dads mechanic said if I fill to top added another. 70 litres of correct fuel and drove the 100 mile back home , car drove  well. Anyway drives to me dads as late just to reassure him I got home  ok as he worries about his daughter, Goes to start car as I told him  no spluttering etc, car wouldn’t start  was cranking but wouldn’t start, get 3 beeps and brakes sign appears

. Gets me dad mechanic  to house next morning, car started no problem he said everything sounded good,  stoped and started it all ok. I then decide to go out in car drove fine. Returned about an hour later car wouldn’t start, left overnight car starts, both sets if keys been used same issue, gets plugged into computer then get 

code control circuit for glow plug controller 1 elecrtrical malfunction P3338 intermittment

battery test replace instead on 780 en had 660 en

replaces battery , omg that looked complicated not sure if being a girl but I thought it was simply disconnecting terminals, as thinking low battery might give issue, sadly me dads mechanic is  in process of retiring clearing workshop out, he’s thinking issue is totally unrelated as car drove over 100 mile drives well sounds fine and thinking more electrical issue.

So do I go down route of auto  electrician route, and if so any recommendations I’m in newcastle upon Tyne 

any advice tips appreciated, thanks

 

Sorry to hear your troubles. Misfueling is easily done. Did it years ago, but didn’t start the car. Surprised at AA’s response. Depends on your level of cover. If you had Relay they’d have transported you and car to garage of choice. Bear in mind they are owned by private equity which is all about maximising profits, so not the ‘friendly organisation’ they like portray.

P3338 is a generic code. You need to get the car scanned with VCDS. If it is glow plugs, which it could be, then they need removed when engine is hot. You can spray PlusGas on them a few days prior to removing. Also use 3/8” ratchet. The last thing you need is one breaking on you.

Regards battery, it should read anywhere from 12.4-12.7v, it will read higher when started. It might not need coded to car on 2006 model. Modern cars have a lot of electronics and diesels need a certain amount of grunt to start them, so that’s one less thing to worry about.

I’d also swap out the fuel filter. Not sure where it is on 2006? On B8 and B9 it’s under the driver’s side chassis under plastic cover. On 2001 B5 it was in the engine.

Id also treat the current fuel to Forte diesel conditioner. It will help the injectors.

Edited September 21, 2025Sep 21 by spartacus 68

I'm surprised there is no pre-ignition with that much petrol in the diesel, but if the engine runs well, so be it.

Do let us know the outcome.

Thanks with AA I have cover through nationwide  Building socierty, think they being awkward., as they said I hadn’t actually broken down as yet,  will not be attempting this myself 😀 but will mention  needs a VCDS scan  can I ask what that stands for,  if I can get to the bottom of it without being too costly will get the filters changed. It’s weird though as when car starts it’s great and drives well

 

 

 

 

13 hours ago, cliffcoggin said:

I'm surprised there is no pre-ignition with that much petrol in the diesel, but if the engine runs well, so be it.

Do let us know the outcome.

It was 10 litres of petrol but then added an additional 70 litres of correct fuel, told a lot of taxi drivers used to do it to the cars prior to a mot. Will let you know outcome, just need to find someone in area willing to assist

On 9/22/2025 at 12:07 AM, Inneedofhelp said:

 Will let you know outcome, just need to find someone in area willing to assist

What further assistance do you need? If the car can be driven it can be taken to a garage for scanning with a code reader such as VCDS.

I’ve tried a few garages, they all busy for the next 2 weeks🙄 and where they recommended  they busy as well can k just ask out of curiosity what a VCDS is

VCDS is a high quality scanner that plugs in to the OBD port of the car. It is connected to a computer for scanning of fault codes and diagnoses. There are a few other decent code readers available which are usually used by professionals. There are many cheaper code readers available that are aimed at domestic users, but they generally don't have the discrimination of better units which means they mislead users with wrong codes. I recommend you either buy a good quality equivalent or get the car diagnosed professionally. Don't waste your money on cheap readers.

Thanks I’m looking for a. Garage to do a reader is vagcom the same thing, got a few garages in mind but not open during week thanks

Vagcom I guess is from VAG (Volkswagon Audi Group) so presumably is equivalent to VCDS.