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
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?