MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: jimmy-s3 on February 10, 2011, 06:47:30 pm

Title: Cold start fault
Post by: jimmy-s3 on February 10, 2011, 06:47:30 pm
Thought id start a new thread on my continous problems!

My car has now developed a new fault which is, when i try to pull away first thing on a morning the car wont really drive properly until the revs drop back down to normal tickover. Its as if there is no throttle control while the cold start is running!? Then, as the revs drop to normal rpm the car suddenly picks up and then its fine!

Any ideas anyone?

Someone said it could be the PCV??
Title: Re: Cold start fault
Post by: v2brett on February 10, 2011, 08:51:14 pm
ive just replaced my pcv mainly as precaution but my Gti seems to start better now, it seemed to turn over a few more times when cold before it fired.
The pcv cost me approx £30 from the dealers mate,  the parts guy said theres a 7-10 day back order on them but managed to source me 1 from a nearby dealer
Title: Re: Cold start fault
Post by: jimmy-s3 on February 10, 2011, 10:50:05 pm
Still unsure if the pcv is at fault?
Not sure what else would cause the problem?
Title: Re: Cold start fault
Post by: v2brett on February 10, 2011, 11:05:13 pm
is there anyone close whose pcv you could try to eliminate it Jimmy?
Title: Re: Cold start fault
Post by: jimmy-s3 on February 23, 2011, 01:03:41 pm
Just checked my pcv valve and all  seems fine, ive blown through the valve and it only works one way!
Getting pissed off with it now!
Anyone else got any ideas?
Title: Re: Cold start fault
Post by: Richn83 on February 23, 2011, 01:42:59 pm
Wait till hte cold start sequence is completed before driving the car?  :grin:

For £30 it might be worth trying a replacement PCV as it might need sufficient pressure for it to demonstrate failure.  Also have you logged for faults with VCDS?

On another thread it was mentioned that there is a soelnoid that controls the cold strat sequence this is from memory but think it might have been '100' you could try removing that to confirm if its related to the start sequence or goes away once the car has been left to idle for awhile?  The thread was about cold starting and people noticig that the 1200rpm idle wasnt working in the cold weather.

Title: Re: Cold start fault
Post by: jimmy-s3 on February 23, 2011, 04:59:27 pm
Listened to the car again tonight, the car has been stood all day. Drove it  whilst it was in the cold start 'mode' and the noise i can hear sounds to me like a turbo spooling over very slowly and very dry???
Title: Re: Cold start fault
Post by: Richn83 on February 23, 2011, 05:06:44 pm
Well unless your gunning the engine from cold your turbo wont be spooling.  And if you are revving the t1t off it just after starting then its bound to drive like a dog as you wont have nice warm oil in and around your turbo.

Think you need to get it logged using VCDS for error codes and parameters when idling, and if there is a noise then a video of the start and the noise would help, if you cant do the above then I would suggest taking to a garage for diagnostic.
Title: Re: Cold start fault
Post by: Boothy on February 23, 2011, 05:15:17 pm
PCV ? :ashamed:
Title: Re: Cold start fault
Post by: ub7rm on February 23, 2011, 05:24:08 pm
Wait till hte cold start sequence is completed before driving the car?  :grin:

For £30 it might be worth trying a replacement PCV as it might need sufficient pressure for it to demonstrate failure.  Also have you logged for faults with VCDS?

On another thread it was mentioned that there is a soelnoid that controls the cold strat sequence this is from memory but think it might have been '100' you could try removing that to confirm if its related to the start sequence or goes away once the car has been left to idle for awhile?  The thread was about cold starting and people noticig that the 1200rpm idle wasnt working in the cold weather.



Can you remember anymore about this cold start solenoid?  I've tried a search for it but nothing comes up.  When the weather was colder the revs would drop down to 'normal' idle immediately whereas now (at the tropical temps of 5 deg c) it sits high for 20 seconds or so before dropping down.  This is what I would consider as normal and what it should be doing.  When it was colder the engine did need turning over more than usual as well.  Not sure if it could possibly be related but I'm sure my car is taking a good while longer to warm up than it used to too.

I have replaced the PCV, thermostat and temp sender to no avail.

The revs dropping down straight away is strange as I would expect it to rev higher, for longer the colder it is - not the other way round as it is at present.
Title: Re: Cold start fault
Post by: Richn83 on February 23, 2011, 05:32:51 pm
Wait till hte cold start sequence is completed before driving the car?  :grin:

For £30 it might be worth trying a replacement PCV as it might need sufficient pressure for it to demonstrate failure.  Also have you logged for faults with VCDS?

On another thread it was mentioned that there is a soelnoid that controls the cold strat sequence this is from memory but think it might have been '100' you could try removing that to confirm if its related to the start sequence or goes away once the car has been left to idle for awhile?  The thread was about cold starting and people noticig that the 1200rpm idle wasnt working in the cold weather.



Can you remember anymore about this cold start solenoid?  I've tried a search for it but nothing comes up.  When the weather was colder the revs would drop down to 'normal' idle immediately whereas now (at the tropical temps of 5 deg c) it sits high for 20 seconds or so before dropping down.  This is what I would consider as normal and what it should be doing.  When it was colder the engine did need turning over more than usual as well.  Not sure if it could possibly be related but I'm sure my car is taking a good while longer to warm up than it used to too.

I have replaced the PCV, thermostat and temp sender to no avail.

The revs dropping down straight away is strange as I would expect it to rev higher, for longer the colder it is - not the other way round as it is at present.

This thread  http://www.mk5golfgti.co.uk/forum/index.php/topic,22317.0.html (http://www.mk5golfgti.co.uk/forum/index.php/topic,22317.0.html) I never got to the bottom of whether it was an R32 part or TFSI but I guess it will have one regardless just might be a different number and placement.
Title: Re: Cold start fault
Post by: jimmy-s3 on February 23, 2011, 10:16:21 pm
I never gun my car from cold, so its not as if the turbo is getting loads of stick?
The car has started hesitating in the high rev range again tonight ?

Does anyone know what the part is under the fuel pump with the rod/arm which i pressume opens and closes something??
Title: Re: Cold start fault
Post by: jimmy-s3 on February 23, 2011, 10:58:38 pm
Im reading that the 'tumble flap' fails on the 2.0 tfsi. What does this control and would it be relevant to my problems?
Title: Re: Cold start fault
Post by: jimmy-s3 on February 28, 2011, 08:51:28 pm
Had my car checked over on VAGCOM at the weekend and only came up with one fault..
01809 actuator motor temperature flap!

Anyone know if that could be related to my cold start fault?
Title: Re: Cold start fault
Post by: Richn83 on February 28, 2011, 10:05:18 pm
http://wiki.ross-tech.com/wiki/index.php/01809 (http://wiki.ross-tech.com/wiki/index.php/01809)

It looks like its related to the aircon system rather than anything engine related.

By the way earlier on I wasnt suggesting you were gunning it from cold, just you had trouble driving off from a cold start situation. 

The tumble flaps adjust/block off the air flow into the cylinders at low engine speeds to help keep a correct air to fuel ratio.  They certainly could affect pull off from cold start if they were sticking open.