MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: alexmccabe on October 28, 2013, 01:55:30 pm

Title: Weird behaviour when cold
Post by: alexmccabe on October 28, 2013, 01:55:30 pm
My car exhibits some weird behaviour when the engine is cold. If I hold the throttle pedal at one place whilst driving just after turn on, the car will kangaroo back and forth, sometimes quite violently. It's as if I am in a car with someone that doesn't know how to use the clutch properly. Once warmed up this doesn't happen.

I've also noticed weird idle when cold - mid temp. It kinda feels like it's misfiring on a cylinder, but not as jumpy, and it is quite infrequent. In my MK4 2.0 GTi, this was caused by the ignition coilpack, but it was a lot more aggressive.

What could be causing this behaviour? It is going in for a diagnostic tomorrow, but I am wondering if I can go into it with a bit of knowledge before hand.
Title: Re: Weird behaviour when cold
Post by: Tortaruga on October 28, 2013, 09:52:40 pm
That sounds like a fuelling issue. Have you replaced your cam follower?
Title: Re: Weird behaviour when cold
Post by: Tortaruga on October 28, 2013, 09:56:21 pm
Although a fuel supply issue wouldn't go away when the engine has warmed up. I don't know, sorry.
Title: Re: Weird behaviour when cold
Post by: alexmccabe on October 28, 2013, 10:53:38 pm
Quote from: Tortaruga on October 28, 2013, 09:52:40 pm
That sounds like a fuelling issue. Have you replaced your cam follower?

Yeah I replaced the cam-follower, though the old one was barely worn.
Title: Re: Weird behaviour when cold
Post by: Human Joist on October 28, 2013, 11:39:37 pm
I have the same symptoms with my dsg gti. I have just changed the sparkplugs as they had been in for 50k and that's improved the situation but now cured it. I was also thinking maybe coilpacks
Title: Re: Weird behaviour when cold
Post by: alexmccabe on October 29, 2013, 03:43:03 pm
The service today showed that the spark plugs were rusted and leaking. Got all new ones, but might have to replace one of the ignition coils.
Title: Re: Weird behaviour when cold
Post by: Human Joist on October 29, 2013, 05:20:05 pm
Is there a way for testing the coil packs at all
Title: Re: Weird behaviour when cold
Post by: Tha_Don on October 29, 2013, 06:47:41 pm
I have the same problem. I've changed the spark plugs but it didn't solve the issue. Let us know if you get it sorted please mate.
Title: Re:
Post by: joelee on October 29, 2013, 07:33:04 pm
Have you tried the temp sender unit as that controls the fueling and so on

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Title: Re: Weird behaviour when cold
Post by: alexmccabe on October 30, 2013, 10:26:15 am
Quote from: Tha_Don on October 29, 2013, 06:47:41 pm
I have the same problem. I've changed the spark plugs but it didn't solve the issue. Let us know if you get it sorted please mate.

Will do. It seems to be behaving much better now, but I will keep an eye on it. If you can afford to, replace the ignition coils as well.
Title: Re: Weird behaviour when cold
Post by: Tha_Don on October 30, 2013, 08:28:46 pm
Quote from: alexmccabe on October 30, 2013, 10:26:15 am
Quote from: Tha_Don on October 29, 2013, 06:47:41 pm
I have the same problem. I've changed the spark plugs but it didn't solve the issue. Let us know if you get it sorted please mate.

Will do. It seems to be behaving much better now, but I will keep an eye on it. If you can afford to, replace the ignition coils as well.

Cheers mate. That was next on my list actually. Seeing as it's pay day tomorrow I might have to treat her to some  :happy2: