Post by: AJP on May 23, 2015, 05:23:36 pm
I've noticed a few times that under moderate to hard braking, usually from mid to high revs, that the car isn't smooth in decelerating.
It's not a brake issue, more that the engine braking is a bit 'lumpy'.
I probably haven't described it very well, but I'm guessing it could be something like an engine mount - mass moving more than it should which affects the momentum of the car.
Sound familiar to anyone?
Post by: AJP on May 27, 2015, 12:24:13 pm
Post by: AJP on June 07, 2015, 06:47:11 pm
Mount? Flywheel? Something else?
Hope someone can at least offer an idea!
Post by: lukemk5gti on June 07, 2015, 06:53:14 pm
First thing came to mind was maybe your a.b.s.?
Post by: AJP on June 07, 2015, 07:47:40 pm
It's quite hard to explain!
I'm 99% percent sure it's engine related rather than brakes though.
If I for example rev up to 4000rpm then lift off, the car slows smoothly under engine braking. But if I apply the brake under the same conditions, it's as if the engine can't adjust its revs in line with the foot brake - and staggers/lurches from say 4000rpm down to 1500rpm. Almost like the revs hang then suddenly drop, making decelleration lumpy. It takes a bit of fun out of the odd blast.
Post by: lukemk5gti on June 08, 2015, 08:58:59 am
I've never heard of it so I'd say it's an uncommon issue but maybe someone else on here has had a similar experience!
Post by: AJP on August 06, 2015, 09:04:31 pm
Just bumping this after reading up and putting 2 and 2 together. It does seem like there's some weight 'shifting' when it shouldn't.
I'm going TTRS at the front soon so want to get this sorted first, rather than have the extra braking force accentuate it and make things worse!
Post by: rich83 on August 06, 2015, 10:33:07 pm
Post by: AJP on August 07, 2015, 09:27:28 am
DSG?Manual.
Post by: rich83 on August 07, 2015, 09:35:52 am
Does the same happen if you brake after youve dipped the clutch?
Post by: Dan_FR on August 07, 2015, 10:12:58 am
If its a much more physical issue, where you can actually feel weight/mass shifting under heavy braking, then i would explore further, checking engine and gearbox mounts, front arm bushes, subframe etc.
Post by: AJP on August 07, 2015, 06:56:31 pm
hmm... strange one...Can't say I've tried Rich, but I'll give that a go at some point - I see your thinking.opcornsoda:
Does the same happen if you brake after youve dipped the clutch?
Post by: AJP on August 07, 2015, 07:03:15 pm
Sounds quite normal to me under heavy braking. Heavy braking in gear will result in slowing the engine very quickly against a huge rotating mass, with the engine fighting to idle/maintain the revs in a smooth manner. If it didnt do this, every time you lifted off throttle in gear, you would have a huge lurch forward with the sudden and drastic engine braking as opposed to the fairly smooth transition you should have.Agree in principle Dan, although I've never heard the mk5 GTI being described as lurchy... so I think it may well be an underlying issue rather than a characteristic of the car.
If its a much more physical issue, where you can actually feel weight/mass shifting under heavy braking, then i would explore further, checking engine and gearbox mounts, front arm bushes, subframe etc.
I did wonder whether it was flywheel related, then read more about the subframe bolt issue and it kind of makes sense. That, or as you suggest, a worn mount.
May well have a drive over to Statller at some point, see if they can take it for a little diagnostic spin!
Post by: AJP on August 07, 2015, 07:04:33 pm
Post by: grumpy on August 08, 2015, 10:47:30 pm
just wondering, does your car have the whiteline ALK?
I know someone who had the whiteline fitted, he said it became 'grabby' at times and needed lubricating to eliminate what you're describing. I think he used silicone spray on it. A while later he fitted the better designed superpro ALK and no more grabbiness - something to do with a metal collar - and why I went for the superpro kit.
Either way, hope you get it sorted.
Post by: AJP on August 09, 2015, 01:07:05 pm
Hi,No, completely standard, as far as I'm aware. Bought the car at the start of April and the only thing I've changed suspension wise is a set of H&R springs.
just wondering, does your car have the whiteline ALK?
I know someone who had the whiteline fitted, he said it became 'grabby' at times and needed lubricating to eliminate what you're describing. I think he used silicone spray on it. A while later he fitted the better designed superpro ALK and no more grabbiness - something to do with a metal collar - and why I went for the superpro kit.
Either way, hope you get it sorted.