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Model specific boards => Golf mk6 => Topic started by: branchespark on 09 March 2011, 07:49

Title: Hump backs and dips
Post by: branchespark on 09 March 2011, 07:49
A little strange one this, but I've noticed with my GTD that, when I go over a certain hump back bridge on my way to and from work, there is loss of power when coming down "the other side". I have also seen this going in to dips.

Has anyone else seen such behaviour? Is some clever wizardry trying to take control of the situation (and, quite frankly, cocking it up)?

It's like a flat spot with loss of power. And no, I'm not tapping the brake pedal at the same time in the hope that I can be a rally driver!!

BP
Title: Re: Hump backs and dips
Post by: Buck on 09 March 2011, 07:52
I've not experienced this in mine (luckily). Does it do it at any other time?
Title: Re: Hump backs and dips
Post by: branchespark on 09 March 2011, 07:54
Only in two places; on one railway hump back and another in a little dip. Very strange and, as with the warty Xenon, I'm starting to feel attached to the occasions!

BP
Title: Re: Hump backs and dips
Post by: flc1962 on 09 March 2011, 08:34
Thats spooky, I've noticed some thing like this as I need to come home a different way, I turn a slow corner in 2nd then start down a hill as I change to 3rd I get that same feeling hard to explain like the car has braked this happens every time in the same place, could we be sub Consciously  taking the foot off the gas? I've the GT TDi....
Title: Re: Hump backs and dips
Post by: branchespark on 09 March 2011, 08:35
I've tried it keeping at steady speed and foot rigid. Same thing!
Title: Re: Hump backs and dips
Post by: Jimmymature on 09 March 2011, 08:57
I've tried it keeping at steady speed and foot rigid. Same thing!

When this happens does the ESP light come on? You may be loosen traction and the ESP decides to take action. I have a hump that I get slight air on and ESP tries to deal with it.


Hope this helps.


Jim
Title: Re: Hump backs and dips
Post by: branchespark on 09 March 2011, 08:58
No, certainly no slipping of the rubber. Going too slow for that.
Title: Re: Hump backs and dips
Post by: PenguinGTI on 09 March 2011, 10:06
I've noticed this also so your not alone  :smiley:

To me it felt like the traction control coming in although I have never had the light come on in these situations. I've never had loss of traction but it feels like the TC none the less.
Title: Re: Hump backs and dips
Post by: Keithuk on 09 March 2011, 12:16
I've heard of this problem before not so much the GTD but the TDI. I could post the link but you would have to join before you could read it. Mine doesn't suffer from this glitch.

You should have posted this in the TDI section?
Title: Re: Hump backs and dips
Post by: Steve30 on 09 March 2011, 17:18
No problems with mine ether , but then again its DSG  :smug:
Title: Re: Hump backs and dips
Post by: ajmoir36 on 09 March 2011, 22:14
Maybe the XDS system doing something, sometimes, going around a corner it can feel a little weird.
Title: Re: Hump backs and dips
Post by: evo1986 on 09 March 2011, 22:29
Felt this many a time just as you come over the pitch of a small slope at lowish speed
Title: Re: Hump backs and dips
Post by: flc1962 on 10 March 2011, 06:45
Any idea's then?.
No ESP light for me and again same place/road yesterday..
Title: Re: Hump backs and dips
Post by: evo1986 on 10 March 2011, 07:34
Not a clue really no ESP light has ever come on in any of the cars I have noticed it in which range from golf match 1.6tdi, scirocco 2.0tdi 170, gtd...........

Mystery
Title: Re: Hump backs and dips
Post by: Wayne on 10 March 2011, 07:57
Any idea's then?.
No ESP light for me and again same place/road yesterday..

Maybe it is doing its job but not lighting on the dash, I know some system only light up on the dash when they are really working.
Title: Re: Hump backs and dips
Post by: p3asa on 10 March 2011, 15:44
I've heard of this problem before not so much the GTD but the TDI. I could post the link but you would have to join before you could read it. Mine doesn't suffer from this glitch.

You should have posted this in the TDI section?

Like you say Keith it has been spoke about in other forums so obviously not an anomaly.
Not sure why it should have been in the TDI section though as petrol users have experienced the same.
Title: Re: Hump backs and dips
Post by: WILLS on 10 March 2011, 16:01
I've also experienced this in a 2.0 tdi audi a5, when going downhill with foot off the accelerator and when you try and accelerate downhill it's almost as though for a second it doesn't want you to!
Title: Re: Hump backs and dips
Post by: mac7 on 10 March 2011, 16:17
I'm pretty sure it's just the fact that the amount of force you are applying to the throttle pedal reduces as the car comes off the bridge/drops into a dip, in the same way your backside lifts off the seat cushion.
Title: Re: Hump backs and dips
Post by: jez_-_ on 10 March 2011, 19:03
Try putting the cruise control on and see what happens?
Title: Re: Hump backs and dips
Post by: Keithuk on 11 March 2011, 00:40
Not sure why it should have been in the TDI section though as petrol users have experienced the same.
Well if petrol version suffer from this then ok but I've only heard of TDI's with this problem.
Title: Re: Hump backs and dips
Post by: flc1962 on 11 March 2011, 06:44
Decided yesterday not to change up just stay in 2nd, so going just a little slower, NOTHING just carrie on... will try again today!!
Title: Re: Hump backs and dips
Post by: branchespark on 11 March 2011, 22:56
I like the cruise control idea, but that also involves playing chicken, as you can't always see what's coming and oncoming traffic has right of way! ;)
Title: Re: Hump backs and dips
Post by: Jimmymature on 11 March 2011, 23:53
I don't believe for a second that it's the foot coming off the accelerator, a hump and a dip would act differently ie one would cause an increase in speed (dip) the other a decrease (a rise)

I'm convinced it's the traction control doing something a little odd!!


Jim
Title: Re: Hump backs and dips
Post by: jahilton2002 on 12 March 2011, 12:38
i've also had this on the same hump in the road..... doesn't feel like the TC to me.... more like it mis fires alittle....
Title: Re: Hump backs and dips
Post by: Jimmymature on 12 March 2011, 20:49
i've also had this on the same hump in the road..... doesn't feel like the TC to me.... more like it mis fires alittle....

It might feel like a misfire, but how can a car misfire on a certain bit of road that just so happens to be a dip or a rise.  It's just not plausible I’m afraid.

It has to be the stablility system doing it's magic.


JIm
Title: Re: Hump backs and dips
Post by: am1w on 12 March 2011, 21:20
Upgraded sound systems needed to really enjoy humping, backing and dipping. :evil: :grin:
Title: Re: Hump backs and dips
Post by: Wayne on 12 March 2011, 21:47
It will be the esp or tc system cutting in.  :smiley:
Title: Re: Hump backs and dips
Post by: mac7 on 13 March 2011, 15:13
Can't possibly be ESP as the system uses no vertical accelerometers, only lateral ones. Its your foot easing off the pedal - simple physics. Coming off a hump bridge is exactly the same as going down into a dip. Being in a lower gear will obviously make the effect more noticable.
Title: Re: Hump backs and dips
Post by: Jimmymature on 13 March 2011, 16:17
Can't possibly be ESP as the system uses no vertical accelerometers, only lateral ones. Its your foot easing off the pedal - simple physics. Coming off a hump bridge is exactly the same as going down into a dip. Being in a lower gear will obviously make the effect more noticable.

Sorry but think you're completely wrong, when the wheels lose traction the ESP or traction control senses it, I had the very same thing occurring in my old A3, foot to the floor over a rise and power is cut when the car goes light!!


Simple physics dictate that your foot will act differently if your going over a rise or down in a dip. Down a dip more force I pushed down, over a rise and less force is used.


Jim

Title: Re: Hump backs and dips
Post by: jahilton2002 on 14 March 2011, 00:06
lol did some testing today :D my bumps on a private road  :evil:

10mph seems to be the "sweet speed" i can do it everytime now.

without touching the pedals and in 1st gear, as the cars front end goes lower than the rear... you can feel alittle resistance.... feels like engine braking/misfire, only for a split sec.... no flashing esp,

same in 2nd going to slow for others gears......   if i go over the hump not being it gear doesn't do it........but ....as the car gos down the hump.... the revs drop 200rpm and it revs up another 500rpm as the cars rear comes down the hump......

turn esp off, still does it.....

i think it could be somthing the ecu  is doing. or its a physical fuel starvation issue.
doesn't do it going up the hill (humps on a hill).
........

anyway thats all.... both my 1.6tdi and 2.0tdi do it??? the mk3 golf gti doesn't  :evil: although sometimes i have to put the splitter back on
Title: Re: Hump backs and dips
Post by: countrytrucker on 17 March 2011, 10:13

Finally someone else has the same problem as me!

On my way home, I go over some big crests and in to some dips. My GTD also cuts the power. I left it in to VW to get looked at as I though it was a fault. I would be driving quite fast and all of a sudden it is like there is a limiter put on. VW said the car feels too light over the crest or feels to much load in the dip then cuts the power. It is like dabbing the brake and the car cutting the power. I was told that it isn't the actual traction control kicking in which explains why the light doesn't come on. I was told there are some other sensors that look after this.

It seems we are stuck with this! It could catch you out when racing if someone is close behind you then the power cuts, suddenly the car behind is now in your back bumper!
Title: Re: Hump backs and dips
Post by: branchespark on 17 March 2011, 18:51
@countrytrucker: spot on. same as me. hmmmm
Title: Re: Hump backs and dips
Post by: am1w on 17 March 2011, 20:47
Oh dear. Diesel disasters. :sad:
Title: Re: Hump backs and dips
Post by: flc1962 on 17 March 2011, 21:00
Its ever so slight, should never cause an accident...
Title: Re: Hump backs and dips
Post by: p3asa on 19 March 2011, 23:25
Oh dear. Diesel disasters. :sad:


PenguinGTI has had this so not exclusive to Diesels
Title: Re: Hump backs and dips
Post by: am1w on 19 March 2011, 23:42
Oh dear. Diesel disasters. :sad:
PenguinGTI has had this so not exclusive to Diesels

Oh dear, dear. So it must be due to the re-map, or DSG, or lack of ACC, or just bad luck. :laugh:
I think I've covered most bases.  :evil: :grin:
Title: Re: Hump backs and dips
Post by: flc1962 on 20 March 2011, 13:44
Oh dear. Diesel disasters. :sad:
PenguinGTI has had this so not exclusive to Diesels

Oh dear, dear. So it must be due to the re-map, or DSG, or lack of ACC, or just bad luck. :laugh:
I think I've covered most bases.  :evil: :grin:

Or could be supposed to do this and your's don't... covered the rest there me thinks..... :tongue:
Title: Re: Hump backs and dips
Post by: am1w on 20 March 2011, 20:49
Thank you flc1962 for reiterating the clarity of my post. :smile: :smug:
Title: Re: Hump backs and dips
Post by: DRC on 21 March 2011, 16:44
Not just GTDs,
"down 'ere Devon way lad" said in south-westerly accent :p there are lots of dips, noticed it in my 110bhp today, pretty weird!
Title: Re: Hump backs and dips
Post by: am1w on 21 March 2011, 19:35
Oh dear, dear, dear. They'll soon be going backwards. :evil: :grin:
Title: Re: Hump backs and dips
Post by: branchespark on 18 April 2011, 10:52
Just been on the A68 in North Yorks / Northumberland and in-between some air-worthy moments, the car definately tries to take control when you want to accelerate while dropping down off a hump. A little disconcerting, but sure I can live with it!
Title: Re: Hump backs and dips
Post by: ajmoir36 on 18 April 2011, 23:10
Mine does it.