Huntin/Hesitating on Startup

[Nilz]

Hi all

I had a heater matrix pipe split on the car recently right at the back of the engine bay, this has since been replaced, however I have noticed now that every morning when I start the car, it hunts and drops rev as if its about to cut out, only does this for about 5 seconds then is fine for the rest of the day after that.

Any ideas what it could be?

Its an AMK 8L 2002 S3

Cheers
Nilz

 

[Stuart B]

I blamed my morning misfiring on HG leak - I also got hiss and bubbles in the coolant tank even after days of not running he car - since the HG replaced (fingers crossed) no morning issues and coolant isn't under pressure when cold.

Why did the heater pipe split? the paranoia in me would question whether someone thing was adding pressure to it and the weakest point went.

Alternatively, did you knock the vacuum hose near the master cylinder and brake servo when leaning in the bonnet? they seem a popular failure.

 

[badger5]

Hi all

I had a heater matrix pipe split on the car recently right at the back of the engine bay, this has since been replaced, however I have noticed now that every morning when I start the car, it hunts and drops rev as if its about to cut out, only does this for about 5 seconds then is fine for the rest of the day after that.

Any ideas what it could be?

Its an AMK 8L 2002 S3

Cheers
Nilz

get a smoke test done.
something on the inlet pipe has likely been disturbed

 

[Nilz]

I had a local garage do the work for me so will give them a call and see if they can have a quick look for me. I know all the inlet pipes were changed to silicone ones a few years ago so hopefully they should be OK, could just be something loose I'm hoping.

 

[Nilz]

@A3-Lee did a smoke test for me (much appreciated) and it did come up with a couple of leaks from under the inlet manifold, looks like it was a couple of the oil breather pipes, ordered a set and will get them swapped out next week, hopefully that will sort the issue out.