Please help diagnose strange vibration/judder Galaxy

wingnut

Recently purchased 09 Galaxy 2.0. Strange issue please help!

1. Smooth as silk at 120 MPH in 5th 6th gear. No issues 1st 2nd.

2. In fourth (40-50 mph) there is a juddering/shuddering. It does not happen all the time, there seems to be not pattern it can happen after setting off or driving a while it comes and goes. It happens not under load, when the car is cruising.

3. The vibration can be felt throughout the car (passengers can feel it).

4. Dropping the clutch / putting it in neutral seems to make it go away it comes back when the gear is reengaged.

5. Engine power feels fine, acceleration, changing gears etc no problems. It doesn't seem to slow the car just make it jump a bit.

6. Can be felt to a lesser extent sometimes in 3rd/5th put more pronounced in 4th.

7. Had two mechanics take it for a run and it didn't happen for them. I have had the wheels balanced and tracked and double checked. The guy that did the tracking said he could definitely feel the vibration when he brought the car to 100 MPH on his ramp but couldn't tell me what it was.

scannerd

petrol or diesel?

wingnut

Diesel

smuggler.ie

Park your car, rev it and hold at intervals 2000, 2500, 3000 for few seconds - if no vibration noticed under various revs most likely its related to wheels or drive shafts

It happens not under load, when the car is cruising.

I would get tires/wheels(all) inspected for bulges, misalignment, balance.

Ninthlife

Im not overly knowledgeable with cars but had a smiliar issue before and it was the fly wheel

wingnut

smuggler.ie wrote: »

Park your car, rev it and hold at intervals 2000, 2500, 3000 for few seconds - if no vibration noticed under various revs most likely its related to wheels or drive shafts
I would get tires/wheels(all) inspected for bulges, misalignment, balance.

Doesn't happen when parked but does happen when on a ramp and drive engaged.

wingnut

Ninthlife wrote: »

Im not overly knowledgeable with cars but had a smiliar issue before and it was the fly wheel

Definitely a strong suspect. My only fear is reading other posts online where people with a similar issue had flywheel and clutch replaced and it did not resolve the issue.

Mechanic has suggested that if the flywheel was an issue it would give issues under load/acceleration where there is no issues there.

Also notice if this makes sense that if going at the constant speed and there is not vibration if I hit a bump or uneven ground it can start up. Its like something is unbalanced but as dropping the clutch makes it disappear I do think it is clutch / flywheel related.

Does anyone know if there is ANY WAY to diagnose to a degree of certainty an issue like this without having the clutch/flywheel out

wingnut

smuggler.ie wrote: »

Park your car, rev it and hold at intervals 2000, 2500, 3000 for few seconds - if no vibration noticed under various revs most likely its related to wheels or drive shafts
I would get tires/wheels(all) inspected for bulges, misalignment, balance.

Have done and brought it in again to get the alignment double checked it bang on and all wheels balanced.

mullingar

Does it happen a)under load, b)cruising or c) coasting in 4th.

Ninthlife

wingnut wrote: »

Definitely a strong suspect. My only fear is reading other posts online where people with a similar issue had flywheel and clutch replaced and it did not resolve the issue.

Mechanic has suggested that if the flywheel was an issue it would give issues under load/acceleration where there is no issues there.

Also notice if this makes sense that if going at the constant speed and there is not vibration if I hit a bump or uneven ground it can start up. Its like something is unbalanced but as dropping the clutch makes it disappear I do think it is clutch / flywheel related.

Does anyone know if there is ANY WAY to diagnose to a degree of certainty an issue like this without having the clutch/flywheel out

The issue I had was just after purchasing the car, new clutch and fly wheel had been fit. Noticed the vibration which disappeared at about 1800rpm and brought it back to the garage. They replaced the whole clutch and flywheel just to be sure.

There is still a slight vibration between 1100 - 1500 rpm bit car has run perfectly otherwise.

My own mechanic said it was something that may never get solved without stripping out everything so just left it as is

wingnut

mullingar wrote: »

Does it happen a)under load, b)cruising or c) coasting in 4th.

cruising, not really noticeable under acceleration more when the car is at a constant speed or dropping speed.

wingnut

Ninthlife wrote: »

My own mechanic said it was something that may never get solved without stripping out everything so just left it as is

This is why I really hate this problem. Its one thing where you pay to get it sorted another if you change half the car and it does nothing. I'm thinking of just living with it. Car is still under engine and gearbox warranty but the mechanic they sent me too said he couldn't reproduce the issue (which is possible as I could go a couple of days between it happening).

mullingar

Odd that its only in that gear in those conditions. Sounds like a power transmission issue. I'd start with a few basics first. Check the driveshaft to see if they are 100% straight and the CV joints

CJhaughey

Happening at only that speed and particular set of conditions would make me suspect a harmonic imbalance in a driveshaft, possibly in the tripod joint.
The only way you may find this would be to swap the parts out for known good units.
This will take a lot of your time however, but seeing as this is the DIY section I am assuming that you have the time and inclination to do this yourself.
If you have to pay a mechanic to do this it will likely cost a decent amount in labour.