Turbo owners...

g60dubster · 20 Nov 2007 at 19:34

chrisstevens said:
If the turbo is boosting around 3k rpm and then I change gear, as soon as my foot hits the clutch (my other foot is not on the accelerator) the revs will rise usually around 500rpm.

DBW if I remember correctly? Engine code - ARZ(late 2000)

No, it shouldn't do that then, but a late 2000 will be DBW so could very well be the throttle pos sensor or throttle body sensor sticking.

Did the battery get disconnected when the work was done? All DBW vag cars require the throttle body to be reset whenever the battery is disconnected.

Know anyone with a VAG-com as the chances are you'll be throwing up some fault codes.

Also ask on any of these golf forums to see if anyones got any similar experiences with that particular engine code (is pretty common for certain engine codes to have their own particular issues)

www.uk-mkivs.net
www.edition38.com
www.clubgti.com
www.vwvortex.com

Shure · 20 Nov 2007 at 20:27

g60dubster said:
No, it shouldn't do that then, but a late 2000 will be DBW so could very well be the throttle pos sensor or throttle body sensor sticking.

Did the battery get disconnected when the work was done? All DBW vag cars require the throttle body to be reset whenever the battery is disconnected.

Know anyone with a VAG-com as the chances are you'll be throwing up some fault codes.

Also ask on any of these golf forums to see if anyones got any similar experiences with that particular engine code (is pretty common for certain engine codes to have their own particular issues)

www.uk-mkivs.net
www.edition38.com
www.clubgti.com
www.vwvortex.com

Thanks for the info :cool:

I'm not sure if the dealer did disconnect the battery when it was in? Its booked in for this Monday for them to investigate so I'll report back when I get an answer.
I did post my issues on uk-mkivs as I have been a member on there for quite a while but I haven't really had any answers

Zuma · 20 Nov 2007 at 20:39

BigglesPiP said:
Probably because the bite point is higher on the clutch pedal, and there is now less time between you letting go of the throttle and releasing the clutch.

I also agree this is a likely scenario.
it's too much of a coincidence that it happened after having work done on the clutch pedal.

it can sometimes take a while to get used to a new clutch or clutch biting point. you just need to get your timing recalibrated (practice)
try coming off the throttle a fraction earlier.

Shure · 21 Nov 2007 at 18:13

Just thought I 'd add to this, on the drive to work this morning I was altering my driving style and by completely removing my foot from the accelerator and then pause for a second before dipping the clutch and changing gear the car seems to drive "normal" or at least how it used to be...

s0ck · 21 Nov 2007 at 18:34

So you've been riding the clutch?

(my turbo don't do this either)

Shure · 21 Nov 2007 at 19:47

s0ck said:
So you've been riding the clutch?

(my turbo don't do this either)

Well I never had the issue before they changed the pedal!

It's definately not driver error. I've had 3 different people drive my car now and it happens for them all inc. one previous golf 1.8T owner

Shure · 22 Nov 2007 at 18:10

Is it possible that some part of the work carried out(clutch pedal replacement & major service) took some time to bed in or the ECU needed to adjust to anything?
The drive home today seemed a lot better than it was earlier in the week although it still wasn't perfect.

mejinks · 23 Nov 2007 at 16:25

My BMW does it, but its designed to do it. Something to do with preload on the clutch I remember reading yonks ago.

BigglesPiP · 23 Nov 2007 at 17:02

chrisstevens said:
Just thought I 'd add to this, on the drive to work this morning I was altering my driving style and by completely removing my foot from the accelerator and then pause for a second before dipping the clutch and changing gear the car seems to drive "normal" or at least how it used to be...

If it bothers you much, a bigger bore blow-off valve would cure it.

Clarkey · 23 Nov 2007 at 17:10

BigglesPiP said:
If it bothers you much, a bigger bore blow-off valve would cure it.

tell me you are not actually being serious, please...

L1J · 23 Nov 2007 at 17:34

BigglesPiP said:
If it bothers you much, a bigger bore blow-off valve would cure it.

How would that work and how can you determine that the standard recirc dump valve limits the flow of air that being "dumped"?

Once the throttle butterfly is closed properly it won't make a difference at all.

BigglesPiP · 23 Nov 2007 at 20:20

Ah, but is it revving up because the butterfly is still open a bit, or because there is still some boost pressure left?

L1J · 23 Nov 2007 at 20:27

BigglesPiP said:
Ah, but is it revving up because the butterfly is still open a bit, or because there is still some boost pressure left?

You really being serious?

A dump valve is situated before the throttle butterfly in the air flow path.

BigglesPiP · 23 Nov 2007 at 20:54

I know, and boost pressure in that part of the system can cause the engine to rev up with the throttle closed.

L1J · 23 Nov 2007 at 21:24

BigglesPiP said:
I know, and boost pressure in that part of the system can cause the engine to rev up with the throttle closed.

So why would a bigger blow off valve sort the problem?

With the throttle butterfly closed the MAF sensor will sense no airflow, the MAP sensor will see a drop in pressure and the TPS will read 0.

How exactly will this make an engine rev?

BigglesPiP · 23 Nov 2007 at 23:05

Enough pressure will force past the butterfly.

It doesn't take much to make an engine rev up a little with the clutch in.

L1J · 23 Nov 2007 at 23:11

BigglesPiP said:
Enough pressure will force past the butterfly.

It doesn't take much to make an engine rev up a little with the clutch in.

Have you ever seen a throttle butterfly? Where is the pivot? If theres pressure acting on the top half and bottom half which way will it move?

Jonnycoupe · 24 Nov 2007 at 00:11

agw_01 · 24 Nov 2007 at 00:13

Not to mention, the butterfly pivot is pretty weighty.

A bit of redundant air pressure isn't going to be anywhere near strong enough to push the butterfly open.

I haven't got a dump valve. Whenever I come off the throttle, the butterfly doesn't stay open. The air goes straight back through the compressor.

Jonnycoupe · 24 Nov 2007 at 00:36

Weight would make no difference, as you have it assisting and opening at the same time as the pivot arm is central.

Lots of air pressure wouldn't be strong enough to open it either, thats the point here. You get exactly the same force holding it closed + the throttle spring force.