2.0 TDI 140, 54' A3 Start up woes, wont crank all the way.

[Kieronboz]

Hey guys, I have an intermittent problem. I went out to my car at 2.00PM earlier, lovely toasty weather, and turned the key in my car described in title as 2.0 TDI 140, 54' A3, it took me 4 turns of the key to start it, when its going its lovely no problems, for comparison I finished work at 8.30PM today, same day, and it started slightly on a longer crank, but first time.

The first 3 times though, feel like incomplete cranks, I turn the key all the way and it makes that typical start up fail crank noise we all know, then maybe it cranks a bit further the next time, on the 3rd it just cranks and immediately stops, then boom it starts fine on try number 4?

I'm no mechanic so this stuff is all a bit alien to me, I understand there's garages to see etc, but maybe someone has some ideas.

Thanks

 

[Matt_Storm]

I had this on the same car if there is lots of white smoke and chugging it could be a porous head otherwise check the fuel filter it may need changing.

 

[Chillout]

I had this on the same car if there is lots of white smoke and chugging it could be a porous head otherwise check the fuel filter it may need changing.

Is it only when hot or cold as it could be glow plugs, duff battery or coolant temp sensor if you could get a scan done that would point you in a direction

 

[Kieronboz]

Hi guys, as far as i can see and remember there has been no smokey issues, and weather wise, its hard to say as its an alien 24 degrees at the minute, I would say the car has probably been cool and done this too.

I shall look at getting a scan!

 

[tdi-man]

some A3 start better when cold then once warm will take a few cranks to turn that's how they work ...

mine did this so I had the hot start map put in car.. never missed a beat since.

but always change fuel filter ever 6 months any way. and use fuel cleaner ever now and then

get battery checked as well as timing

 

[@udi A3]

reading your description sounds like a flat battery/iffy starter / iffy wiring to the battery or starter. if the battery and starter were good it would crank over and over.

 

[Boon]

reading your description sounds like a flat battery/iffy starter / iffy wiring to the battery or starter. if the battery and starter were good it would crank over and over.

i'd be checking these first too

The glow plugs won't actually work over 9deg C of the engine coolant temperature even though the light comes on for a few seconds.

I also have had the hot start map and have had no problems since but I don't think this is the cause of your problem, I'd say as above battery, starter and/or wiring

iirc they don't like starting below a cranking speed of approx 830rpm so all the above could play a part in this. The cranking speed can be checked with VCDS by measuring the engine speed whilst turning the key if you unplug the main big round wiring loom into the top of the engine (just behind the fuel lift pump) then remove the fault code that'll appear due to removing the loom!