Annoying off throttle jerk!

[CazzaVR 0]

Pretty sure they are around £40 (at least they were when I bought one 4 years ago!).

[Critical_Mass 10]

:gulp: £40. I'll give them a bell and decide then. Least buying a brand new one at £40 it'll last another 15 years.

[RW1 0]

A little bit shy there, 034 133 283 - Dashpot: £44.41 + VAT = £53.30.

 

.

[Kevin Bacon 5]

I must admit, I last bought one 6 or 7 years ago. Didn't think it have gone up that much!

[Critical_Mass 10]

oh fck me. :lol:

 

Suppose a second hand one would be good initially to see if it solves the problem. If it does a new one it is.

 

cheers for the part no. RW1

[mookie 0]

Did you ever get this sorted out mate?

[Critical_Mass 10]

No mate, i didnt if im honest, it slipped down the list of priorities, even more seen as its now a weekend car.

[Pete 0]

Mine is doing the same, going in for a service in 2 weeks and asked them to look into it so I'll report back if it's sorted...

[24V Renshaw 0]

It's the throttle damper.

 

Jay

[Corradoholic 10]

It's the throttle damper.

 

Jay

 

so was it the throttle damper?

[Pete 0]

Mine is sorted, it was the engine mounts. You could move the engine with the palm of your hand about 3 inches.

[Corradoholic 10]

glad yours is now sorted.....i've changed my engine mounts and it hasnt sorted mine out. did you change your gearbox mount too?

[Pete 0]

Yeah I did the three, though the downside now it a fair bit of vibration I'll look to change to vibratechnics in a year or two when money is flush.

 

I was getting the judder, plus sometimes it would be accompanied by "squelch" noises, not sure what that was caused by, maybe engine movement was causing rubber/driveshaft case wiggle???

Edited September 1, 2012 by Pete

[Corradoholic 10]

im still suffering with this off throttle jerk. Have checked the dash-pot and it does appear to be damping and adjusting it hasnt had any real impact.

 

Was wondering if it could be anything related to the throttle position sensor? if its reading incorrectly could this cause the quite violent off throttle lurch im experiencing?

[Pete 0]

Have you checke the tension in the actual throttle cable? If its got a kink in it or is loose in the engine bay it could be whipping around ithe engine bay when you go on/off throttle.

[Critical_Mass 10]

I dont know if this is associated with the jerk, but when i try to go at a constant speed and RPM, if feels like something is juddering around under the enginer bay. Making me feel the need to accelerate or de-accelerate. its an odd one to explain.

 

Peter - vibratechic mounts wont get rid of the vibration, they're stiffer so if anything will increase vibration.

[Corradoholic 10]

Have checked the response of the throttle in relation to the pedal and theres no lag whatsoever so ruled the cable out.

 

I also find that if not carefull, when driving at slow speed, the car can almost end up kangarooing like a learner driver....thats why i keep thinking its a throttle issue, which led me to the throttle position sensor....but i dont really know what it does :scratch:

[Pete 0]

 

Peter - vibratechic mounts wont get rid of the vibration, they're stiffer so if anything will increase vibration.

 

I'm currently using the group buy pol inserts which are pretty much solid, so VTs should be more comfortable than what I've got.

[Kevin Bacon 5]

I've driven 4 different Corrado 24Vs (2 x R32 and 2 x 2.8 24V) and they have the off throttle jerk too. It's worse the lower gear you're in because of drivetrain shunt. i.e. in 4th and 5th it's no where near as bad as the gearing is taller, which smooths it out.

 

It shouldn't be really harsh, but engine mounts can affect it, as can the ECU's happiness with the sensors. Any fault codes in VAG-COM? Not that OBD1 tells you a lot! Idle valve OK?

[Corradoholic 10]

yeah, fourth and fifth its nowhere near as noticable but its is deffinately worse than what it should be as ive never really noticed it in the previous vr's ive had but it is very pronounced in this one.

 

Ive just got the bentley manual through the post...and quickly learned that i need VAG COM to make 90% of it useful :? so that will be my next pick-up i think. then i guess its a case of working throught the temp sensors etc. presume TPS would show up when scanned if faulty.

 

I have just aquired an replacement ISV so hoping to fit it this weekend.

 

will report back.

[Critical_Mass 10]

Kev what you describe there is exactly how it is. My front engine mount was replaced due to this jerk, but didnt sort it. The rears showed no sign of movement and arent that old anyway.

 

Will scan my car just in case. But dont think it'll come up with anything.

 

Could the adjuster on the throttle body for the cable affect things?

 

Throttle position sensor?

 

Pete - apologies thought you were running standard mounts.

Edited September 13, 2012 by Critical_Mass

[VW_OwneR_85 2]

havent read through all 8 pages but im assumeing this jerk isnt fixed? , well me and a m8 picked up an audi a4 realy cheap which we had the intention of sorting out a few issuse and selling on for profitt, one of its problems was a suspected clutch problem hence why it was going cheap, on a test drive we thought it was a motor/gearbox mount as on acceleration it juddered like if the engine was rocking, turned out to be a realy badly worn CV joint,

[Kevin Bacon 5]

Found the cause of my Jerk chicken..... a totally and utterly f'cked gearbox mount. A solid rubber VAG one too, which has only lasted about 9 months.

 

It looked fine from above when wobbling the engine about, but a long pry bar from underneath revealed a different story. The whole gearbox lifted up a good 2" easily on the bar.

 

So, back to Vibratechnics then. I really don't want to, but I'd rather have a bit more noise / vibration than this really bad jerking.

[davidwort 0]

Found the cause of my Jerk chicken..... a totally and utterly f'cked gearbox mount. A solid rubber VAG one too...

 

I wonder if it would be possible to fit a dog-bone mk4 mount under the gearbox too, mk4 style. Would that help?, or is it lifting rather than front/rear forces that is the problem?

I know the dog-bone sits inside the subframe but it doesn't look like there would be much fabrication involved.

 

The mk2/3/Corrado GB mount is basically a design for the 1.8 8v engine so not surprising it's not up to coping.

[Kevin Bacon 5]

Yeah I've had it on the ramp to look into that possibility because the O2J in the Polo GTI has a dog bone mount, but there's no where to bolt a bracket onto the VR6 02A.

 

Yep, the standard mount barely copes with a standard VR6 engine. The ultra snappy and torquey R32 just eats the mount in no time. The VT is up to the job, but as you say, a Dog bone would be a lot better. It's probably possible with a lot of custom work but as winter is approaching, I'll take the easy option :D