Cranks but no start (was intermittent)

[J0N]

Hi All.

First time poster. I have a 2006 Audi A4 Avant 2.0 TDi. I have had an intermittent problem that now appears permanent. On the first occasion I’d driven about 5 miles parked, turned the engine off. I Immediately tried to restart the engine and it wouldn’t start. I tried for about 5 minutes (crank but no start) and it eventually restarted and ran fine the next month. Last Sunday I went to start it and it did the same thing crank but no start. I gave up after 3 attempts as to not drain the battery. I left the battery charging for a few hours as I suspected it was possibly a bad battery as I hadn’t used it the previous day. Later that day I tried again and it started first time. Tried it again a little later and it wouldn’t start but did on second attempt. From research I have done I think it could be the glow plug relay because for the next day or two when it wouldn’t start I realised I could turn the key and no glow plug light would display but if I kept turning the key about 8 times the glow plug light would come on and it would start perfectly. That only lasted a day though and now I can’t get the glow plug light to come on at all and all it will do is crank but not start. Does it sound like a glow plug relay to you?

[Magnet]

Hello Jon,

Sorry but my experience of diesels is rather limited, but personally I would be tempted to discount glow plugs since I understand they generally don’t come into the equation until the temperature drops below c 5 degrees. 

Relays, associated with the fuel pump/s may be worth investigating. 

Very often, it is much easier with these tings to invest in an hour’s services of a diesel specialist, but I would seek some local recommendations before choosing one. 

Kind regards,

Gareth. 

[J0N]

Hi Gareth,

Thanks for taking the time to reply. It has been stressing me having no car. I am leaning towards taking it to a diesel specialist but money is a bit tight right now so I was hoping it might be something obvious I could sort myself. Then again I don’t want to throw money at something that might not be the issue. I hadn’t considered fuel related relays so I’ll look in to that. Thanks, much appreciated.

[Dan3222]

Hi Jon,  this could be caused by a number of separate issues and I feel that you should have the vehicle codes read to see if any codes tell you what it is. My guess is that it’s an electrical fault somewhere. I doubt it’s fuel related. Very difficult to say.

[Dan3222]

Are you a member of The AA or such like to get them to come and fault read it for you?

[J0N]

Cheers Dan, getting the codes read does sound like a good idea. I haven’t got AA unfortunately but if I can get the car to start this morning I will take it somewhere. Thanks for your help.

[J0N]

Update. Wanted to get to ecu but couldn’t due to the location of two screws on the housing. While I was trying crank with no start a few times a friend gave the ecu housing a wack with his hand and it now starts every time. Glow plug light shows on the dash and it starts. Pretty sure this is the glow plug relay which is located under the ecu. I will still get it checked as I’m sure it’ll happen again sooner or later.

[Dan3222]

That’s a lucky result. But yes definitely get the codes read. 

[Petrol head]

On 3/23/2019 at 2:31 PM, J0N said:

Cheers Dan, getting the codes read does sound like a good idea. I haven’t got AA unfortunately but if I can get the car to start this morning I will take it somewhere. Thanks for your help.

Hello Jon,

Could you please give the update so it may help others..?

Thanks,

Jose

[J0N]

Hi Jose,

I changed the glow plug relay and haven’t had any issues since. Hope it helps someone else.