Loss of acceleration/ power

[Vish_s3]

Hi guys,

Last year I took my car to VRS Northampton and got a stage 2 + APR map as well as a Sachs performance clutch installed. The car was running great at 376hp with the remap, full Milltek turbo back exhaust and Ram Air induction kit. When I initially drove the car for the first few months I noticed that with the increase in power I was getting some wheel spin in 1st and 2nd gears. It’s now coming to a year and I’ve noticed a few things.

I recently started to hear some knocking noise from under the car when the clutch is disengaged. When I put my foot down on the pedal this disappeared. The noise is inconsistent and seems to be less once the car has been driven. I also noticed that I was getting a shudder on initial take off in first and also in reverse. Never felt this before.

Recently I’ve noticed that when I take off the wheel spin that I was getting in the first two gears is no longer there and I can feel that the power from 1k to 3k RPM is considerably less.

I drove down to VRS for them to have a look however when I got there the noise had completely disappeared and I was told after a short drive that the car was fine and there were no issues.

what keeps bothering me is that I can still here the knocking noise on odd occasions from underneath the car and I’m still not getting the initial pick up in the first two gears that I was before and no wheel spin at all no matter how hard my foot is down.

I don’t really know what to do or what could be causing this and would appreciate any advice. I appreciate that this could be a number of potential issues if it even makes sense to anyone.

Its driving me crazy so appreciate anything that could be suggested.

Thanks

 

[samuelh_888]

Single mass flywheel or dual mass flywheel?
I can’t say the clutch reducing power - did VRS run any diagnostics?

 

[nluk100]

I would imagine the two issues are not related. Knocking could be your downpipe knocking on the propshaft (common issue) or something like a snapped arb drop link. Need to get under the car really and check all the bushes / mountings.

Power drops usually log something so if you can get a local member with vcds to do a scan (or buy a bluetooth dongle and use an app) then this could help with the next steps. Have you checked the basics like changed the DV?

 

[Vish_s3]

Single mass flywheel or dual mass flywheel?
I can’t say the clutch reducing power - did VRS run any diagnostics?

Dual mass flywheel, no they didn’t. Just took the car for a spin and said they couldn’t fault it.

 

[Vish_s3]

I would imagine the two issues are not related. Knocking could be your downpipe knocking on the propshaft (common issue) or something like a snapped arb drop link. Need to get under the car really and check all the bushes / mountings.

Power drops usually log something so if you can get a local member with vcds to do a scan (or buy a bluetooth dongle and use an app) then this could help with the next steps. Have you checked the basics like changed the DV?

the noise disappears when I put my foot on the clutch, checked underneath the car to see if anything was knocking but couldn’t find anything that could cause this. I will have to check the DV and as u suggested find a local member with a vcds to do a scan. Thanks

 

[William McGougan]

If it goes away with foot on clutch it's most likely dual mass flywheel, I had the same issue then I fitted a Sachs performance clutch/flywheel and found my original flywheel was basically split and was the cause of the rattle

 

[nluk100]

If it goes away with foot on clutch it's most likely dual mass flywheel, I had the same issue then I fitted a Sachs performance clutch/flywheel and found my original flywheel was basically split and was the cause of the rattle

Or the clutch release bearing.

 

[William McGougan]

Or the clutch release bearing.

Yes or that but more likely flywheel if it's a knocking noise

 

[prt57]

My S3 was flashed to APR stage 2+ at VRS with just a downpipe and an intake.
Last year as part of having other work done, I had the car on the dyno at Awesome to check everything was performing fine as I had added more performance parts.
The car was logged over three performance runs and I was informed that the software was working fine with my modifications.
So, if you want a 2nd opinion about how your car is running with the APR software there is no better place as Awesome is the HQ for APR in the U.K. I think VRS should have logged the car rather than just gone for a trip from what you have said.
Just by chance, you have not selected one of the other maps by accident as I think they are changed via the cruise control stalk. My car did not have CC at the time so I only have one power map. I prefer the Awesome experience.
Have you checked the DV is working properly and everything else is all performing properly?
Also, they would diagnose the knocking noise. They are quite pricey but all the work we have had done over the last few years for my son and I has been first class.
AKS would also be able to help out with the mechanical parts but they don’t have a Dyno. They are agents for Revo.

 

[BrummieLad]

Two prime candidates, it’s either thrust bearing or flywheel. Do you get any vibration with the car at idle? If so then it’s definently the flywheel. Gearbox needs to come off to diagnose this properly I’m afraid.