I need a bit of help on diagnosing the source of a rumbling noise.
For several weeks I hear a rumble (one or two thumping's) from the front of my car when I do a sharp right turn (90°) in moderate velocity (at least 30 Km/h).
- There are no suspicious sounds when doing a left turn.
- The noise happens only once/perhaps twice when I start the turn, not while turning. I can make several full turns on an even parking space without additional noises
- I think (unsure) the noise becomes more audible when the road is uneven/inclined.
- I think (unsure) that the sound originates from the front left area.
- Two months ago the car was in a workshop for gearbox repairs, perhaps some component was damaged there or mounted incorrectly (the entire engine carrier was removed).
- I am unsure if the sound developed gradually or of a sudden
- There are no unusual sounds when I hit the brakes or accelerate
- When driving on a rough dirt-road I think that I hear the noise, but I am unsure because background noises overlap.
- Since the noise only happens when doing a sharp turn, most of the time on uneven/inclined roads, I cannot judge if the car behaves differently.
Some informations about the car
It is a 2009 Opel Astra H Caravan with about 140 KKm. It is a FWD, manual transmission. It has an ordinary McPherson-suspension. The front shock absorbers are becoming weak, I hear them them every day when I need to move over an higher-than-average obstacle on my driveway. I don't know if that's part of the problem. I plan to replace them after the winter.
The following link illustrates the control arm. Link
I also have a illustration of the suspension
Both stabilizer links got replaced by me because the seals where ruptured (one before the gearbox repair, one after).
When I changed the wheels two weeks ago there was no feel-able play on the wheel/stabilizer links/control arm/steering knuckle. I am a bit unsure of those results because I did not use a crowbar/similar tool to check the control arm and the stabilizer links where under tension because I was using a single car jack to raise the vehicle.
I am inclined to think that ball joint on the control arm is worn, perhaps somebody could point out other candidates or checks?
