Hi,

I've had an intermittent rattle/shake from the front driver's side of my car intermittantly when i reach 75-80ish on the motorway. It's very loud, can be felt throughout the car, not sure if i can just feel it through the car or through the steering wheel. Once it starts, i have to reduce speed to ~ 65 to stop it from happening.

It started after a cambelt change & service and has become worse over time. It doesn't start immediately, car typically have been running for 20 mins before it kicks in, and it's not always there - somedays it kicks in at 90 (cough), others at 75.

It's definatley speed related - while it's happening i've popped the clutch and reved the engine with no difference in sound.

From digging about on the forum i'm thinking wheel balance, and will try and get that looked at tomorrow.

I'm not sure if a knackered engine tray may do this - it has a crack in it, but generally in one bit - possibly air flowing it causing it to resonant?

Any other ideas? I need to get it up on a ramp!

The mechanic that did the service doesn't believe it's his fault, and i've fallen out with him, since he's done some bad servicing on my car and someone elses, so calling it quits now and changing mechanic, but want to avoid being charged a bomb for someone elses ballsup.

Thouroughly check your tyres. I had a similar issue on a Vectra I had, at 65 / 70 it had symtoms similar to yours. Turned out to be a massive bulge on the inside (under car) edge of the front O/S tyre. Dangerous stuff!

I'm thinking this has to be related to tyres, wheel balance, wheel bearings, driveshaft balance or CV joints. So I'd start by checking the bearings for wear, then carefully examining the tyres for bulges or out of round wear .

:iagree: - sounds like it could be a wheel balancing issue. Possibly a sticky wheel weight has come off?

Steve

Taken it to a service center for wheel balancing, no problems identified.

Just put it up onto a ramp and took a look underneath - sump guard is now in 3 pieces, hanging loose. Didn't have time to pull it off, but removing that'll be the next step.

Will take it off this evening and see if it fixes it.

Ps: going 1 way down a road hits in at 75, other way 85. Unknown wind direction, but links it to airflow!

T

Now suspecting the undertray then. As mine is in one piece, I've never had this issue.

No - to me it sounds identical to the shaking I had in my Fabia. Its speed related and slowing down stops it.

Its the DMF IMHO. Mine had nearly shaken its to the disintegration stage before the clutch / flywheel change two weeks ago. If its not, I''l eat my (old) DMF.

No - to me it sounds identical to the shaking I had in my Fabia. Its speed related and slowing down stops it.

Its the DMF IMHO. Mine had nearly shaken its to the disintegration stage before the clutch / flywheel change two weeks ago. If its not, I''l eat my (old) DMF.

Pictures of you eating your old DMF please

Just spend half an hour trying to fix the tray, gave up and pulled it all off. Turns out the entire drivers side and rear of the tray had come away from the mounting points, as the drivers side mounting bit of plastic had completely split in two.

Driving without it - no rattle at all. Now i just have to work out if i should replace it - and the sump filled with sump filler that's underneath it!

Time to go to a scrappy!

Pictures of you eating your old DMF please

...

Munch, munch, hmmmm, niiice.

Having loads of trouble trying to find the right parts.

The undertray itself is 1J0 018 930B, but I actually need the plastic bit this screws into the of the drivers side, including how on earth I get to replace it!

Any body got info/ideas?

Thanks!

1J0825250J - possibly. Octavia 1998

Will talk to mechanic tomorrrow...