Cupra 280 Weird Creaking noise

[Harman]

Hello,
I have recently discovered a weird creaking/rattling noise which only occurs when the car starts to accelerate after coasting at idle speed. If I put it in 2nd and slow down so that the car is moving using engine idle and then accelerate, the creaking noise happens and then goes away after 1.5k revs. I've had the car on a ramp and the mechanics spent a good couple hours seeing if there are any bolts loose on the car (we thought it was wishbone) but couldn't find anything.
Does anyone know what it could be? Diff, gearbox?
It's a manual transmission, had a Sachs clutch fitted, exhaust and map. Mechanic said I could have chipped a tooth on the diff because of the extra power going through the components. I haven't heard of anyone having diff problems on the forum when they tune these cars? Anybody got any ideas?
Thanks

 

[LouG]

They talk absolute crap, don't they. Does it do it in higher gears? Does it have a metallic tinkling sound? Like preignition? That shouldn't happen, but funny things happen with cars.

 

[Harman]

I Wouldn' say they're inexperienced and I think they would've heard if it was detonation. Ive only tested it up to 4th but the creaking gets quieter the higher the gear you're in. It's perfectly smooth when cruising and I haven't detected any loss in power. When the car is up to operating temperature the creaking noise goes away. I've thought about the idea that the place that did the clutch change may have used the wrong oil which may have accelerated wear on the gearbox components but I have no idea.

 

[bradleymarky]

Hello,
I have recently discovered a weird creaking/rattling noise which only occurs when the car starts to accelerate after coasting at idle speed. If I put it in 2nd and slow down so that the car is moving using engine idle and then accelerate, the creaking noise happens and then goes away after 1.5k revs. I've had the car on a ramp and the mechanics spent a good couple hours seeing if there are any bolts loose on the car (we thought it was wishbone) but couldn't find anything.
Does anyone know what it could be? Diff, gearbox?
It's a manual transmission, had a Sachs clutch fitted, exhaust and map. Mechanic said I could have chipped a tooth on the diff because of the extra power going through the components. I haven't heard of anyone having diff problems on the forum when they tune these cars? Anybody got any ideas?
Thanks

Is it like a pinking noise kind of like you are in too higher gear but then goes when the turbo kicks in, if so mine started doing this last week but stopped.

 

[Harman]

Isn't that noise attributed to preignition? How did it randomly stop? Yeah you can't hear it above 2k revs

 

[LouG]

It's difficult to diagnose without hearing it. In trade talk there is a huge and noticeable difference between a creak ( worn mounts, parts rubbing) and a rattle (preignition, loose fittings)
Can you post a vid?

 

[bradleymarky]

Isn't that noise attributed to preignition? How did it randomly stop? Yeah you can't hear it above 2k revs

Started doing it again yesterday, i`ve checked a few videos and it does sound like pre ignition. going to do a video today and post it. I do have a tuning box fitted so not sure if thats to do with it, cars a 65 plate fr diesel.

 

[LouG]

Is there a facility on the box to adjust ign timing separately? If so, you could knock it back 5 degrees and see if the noise goes.

PS what fuel octane are you using? Can you increase it?

 

[Harman]

I've had 4-5 people look at it now and they've all said it sounds like a driveshaft or CV joint, I'll try and get a video of it soon. I don't think it has anything to do with preignition

 

[Harman]

Yh I've just been to a transmission specialist who said it sounds like a drive shaft, but says there isn't much to worry about yet since the noise goes away when the car is up to operating temperature. Guess illI just have to keep an eye on it to see how it progresses. As for fuel I always run Momentum99 or Vpower but I doubt it was ever misfiring