Dead A4 2.5 TDi Quattro!


Registered User
Nov 21, 2013
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Caithness, Scotland
I'm totally new to here but hope some of you guys will be able to shed some light onto my troubled A4! I bought the car on Saturday and everything was going perfectly fine. Then, on Sunday afternoon whilst driving home from a relatives, it suddenly lost all power! I pulled over, the engine still running but really struggling. I turned it off and it hasnt been able to start since. It's as if it's starved of fuel. There was some air in the pipe leading from the fuel filter but this has since gone. Fuel seems to be getting to and from the filter just fine and also from the fuel pump. No lights or errors showed up on the dash prior to dieing and it's still showing that everything was fine. The car is a 2001 Y Reg 2.5 TDi Quattro Sport with 133,500 miles. Similar problems on other forums are pointing to a knackered Fuel Pump, but I'm hoping to God that isn't the case! Any help would be greatly appreciated! Cheers.
have you had the car scanned with vag-com. This is the first thing to do. There is a few things that could be wrong but from what i have read about a sudden loss of power on the 2.5 usually turns out to be the high pressure pump. If your anywhere near North London i wouldnt hesitate to talk to Chris (adamss24) he knows these engines inside out. I dare say he will be online soon and give you some guidance
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Sounds like what happened to my 2.5tdi. Injection pump overhauled by an ex Lucas guy and it's been great, well worth the £600 (ouch, it was just before Christmas 4 years ago)
That's just what I've been fearing. I've not had time to do much more than get the car home as I've had to go 400 miles away at the start of the week to work! I couldn't be much further away from North London. Live just 10 miles from John O' Groats!
There shouldn't have been air in any of the lines so that could still indicate an air lock. You could loosen some of the injection pipes at the injector end and crank her over to see have you have fuel at the injectors. These engines are hard to bleed and it can take a bit of cranking to get all air through so you need a good battery. Even fuel at the injectors doesn;t guarantee that the injection quantity timing etc is correct as a faulty pump can still supply fuel but in the wrong quantities and at the wrong time. If bleeding doesn't help then scan for codes.
I tried bleeding it once I got it off the side of the road, but it didn't help. I'll get it scanned when I get back next week. Cheers for the advice.
Post your fault codes when you get it scanned. I would suspect the pump. I had 2 very similar failures with mine and the pump ecu is renowned for being fragile.
Finally scanned and 5 codes were thrown up. 00523 Intake Air Temperature Sensor, 01375 Valve for Engine Mountings, 00575 Intake Manifold Pressure, 01441 Low Fuel Level Sensor and 01318 Control Module for Injection Pump.
The main code there which I think is indicating the problem is 01318 which I believe indicates a faulty pump ecu. This is a common and well documented fault. (Mine has failed twice in 6 years and 110k miles). Chris Adams (adamss24) will offer best advice and will no doubt be along shortly to comment. I took the cheap and easy option 1st time and got the ecu repaired but it was not a great success. The car ran but was smoky and hard to start hot or cold and had flat spots etc. I suffered on but it failed again a short while ago and I took the pump off and got it reconditioned this time which included a new ECU on the pump. I had to get the pump immobiliser recoded to the car by AN Other as I didn't have the kit to get the PIN code but it is like a new car since. Repaired ECU will cost around £300 all in , reconditioned pump nearer £700 + labour if you can't do it yourself. I can only go on my own experience but I would go for the more expensive fix as I reckon that I will save the difference in fuel in about 12 months as it is way easier on diesel since the last repair.