Engine cranks slightly longer than it should Audi A4 2002 TDI

alsiet2011

Hello there,

Since I bought my Audi A4 4 years ago I've been having this re-occuring problem pretty much every time I start the engine.

I wait for it to prime, I turn key and the engine turns over a number of times before it starts. This process takes about 1.5 seconds of the engine turning over before it fires up. This happens 8 out of 10 times I start it and sometimes fires up immediately as it should. No engine faults appear in diagnostic tool and no dashboard warning lights appear.

I've brought it to the garage and they can't find fault. It's not a huge issue atm but it's a bit annoying and I know its wearing out the starter motor more than it should. The weird thing is is that it takes the EXACT same amount of time each time before the engine fires up leading me to believe that theres only a small issue thats causing this. Something to do with fuel not being pushed to the engine perhaps? I'm no mechanic by any stretch of the imagination but would love if anyone has any input on this type of issue and why it occurs?

Thanks


Audi A4 2002 1.9 TDI
194,000 miles
Company car for 155,000 of those miles on UK roads.
Very well maintained and serviced (just fully serviced last week actually)

George Dalton

Does it happen when the engine is hot and cold?

Try turning on the parking lights before you start it next time.

alsiet2011

George Dalton wrote: »

Does it happen when the engine is hot and cold?

Try turning on the parking lights before you start it next time.

Thanks for the response. Yeah it happens at cold / hot starts. Some times when its warm / cold the problem goes away. It seems to be very random.

Turn the parking lights on you say.. that sounds interesting and very easy to check . Ill do that later for sure.

What would the reasoning behind this be if you don't mind me asking?

George Dalton

Have seen it before on them where a faulty headlight switch causes poor starting. If it starts easily with the parking lights turned on then replace the headlight switch. I have no idea how the switch causes the poor starting, but it does happen on these A4s.

alsiet2011

George Dalton wrote: »

Have seen it before on them where a faulty headlight switch causes poor starting. If it starts easily with the parking lights turned on then replace the headlight switch. I have no idea how the switch causes the poor starting, but it does happen on these A4s.

thats great thanks! ill try that later on and let yuo know the results

turbojunkie

I've been having the same problem as the OP on a 01 A4 TDI. Garage couldn't find anything wrong. Just tried the parking light trick and... problem solved!! A strange one, and wish I had posted the problem here sooner. Anyway, many thanks to George Dalton

alsiet2011

turbojunkie wrote: »

I've been having the same problem as the OP on a 01 A4 TDI. Garage couldn't find anything wrong. Just tried the parking light trick and... problem solved!! A strange one, and wish I had posted the problem here sooner. Anyway, many thanks to George Dalton

wow thats fantastic. im in the same boat ie. garage find no fault. ill deffo try that after work!!

alsiet2011

alsiet2011 wrote: »

wow thats fantastic. im in the same boat ie. garage find no fault. ill deffo try that after work!!

I tried that there and it worked just like you said. I can't believe it. Four year mystery solved. Thanks so much. Now I'll just a new light switch

mickdw

Crazy stuff. Ever seen it on other vag stuff? I know of a 1.9 Octavia doing this.

Thatnastyboy

Im probably WAAY off here, just something that popped into my head

But is it possible the light switch has a connection to the priming of the fuel pump?

I know a lot of cars prime themselves once they're unlocked/door opened/key in ignition type of thing..

Just an idea, did anyone else think the same?

George Dalton

mickdw wrote: »

Crazy stuff. Ever seen it on other vag stuff? I know of a 1.9 Octavia doing this.

No only on A4s.

On the Octavia, is it hard to start when hot but ok when cold?

Nonoperational

Pretty cool thread I must admit!

mickdw

George Dalton wrote: »

On the Octavia, is it hard to start when hot but ok when cold?

Might well be. What's the advice there.

alsiet2011

alsiet2011 wrote: »

thats great thanks! ill try that later on and let yuo know the results

hey george. listen thanks VERY much for that titbit of information with the headlight switch affecting startup. 4 year old mystery now solved.

im jsut curios, would you think that the problem is in the headight switch itself? like, if i replace the switch would it be safe to say that this wud resolve, or is it imposislbe to tell.

Im just wondering cause if i wana sell the car i want to hav it in the best possible shape and explaining to the buyer that they need to have park lights on to avoid a longer cranking period wouldnt fill them with confidence.

Thanks in advance