Noise when turning

[djnolan]

I have an 87S car and it makes a grumbling thump-thump-thump noise when turning at a slow speed, also when starting engine it make similar grumbling thumping noise. It is not a metallic noise. Can anyone offer a suggestion as what to look for?

[jjeffries]

DJ, I work for a car manufacturer and for situations like this, we provide dealership service advisors with a questionnaire to go thru with the customer. Some of those questions would be useful for you to answer:
- is the noise from the front or the back of the car?
- left or right?
- is it a new noise? If yes, did it start after any recent work, or event (eg, hitting a pothole)?
- any correlation to ambient temperature?
- does the thump-thump-thump change or go away as road speed increases? Do you hear it when turning left, right or both?
- is the engine noise correlated to engine speed/RPM?
-when you look at the engine, is anything looking different to normal (eg, belt tension? PS Fluid level?)
You'll see where I'm going with this...we need more more information to be of help. Best, John

[djnolan]

John thanks for your questions and here is more information.

Originally Posted by jjeffries

- is the noise from the front or the back of the car? Back of car underneath perhaps around transaxel. I have looked for anything loose and did not find anything. eg. shook the exhaust, brake lines, stabilizer, shocks, moved suspension up and down, but have yet to put up on lift.
- left or right? seems equal
- is it a new noise? Maybe. If yes, did it start after any recent work, or event (eg, hitting a pothole)? Engine mounts recently replaced, so maybe it is a new noise or maybe it was masked by engine mount noise.
- any correlation to ambient temperature? None noticed
- does the thump-thump-thump change or go away as road speed increases? Heard during slow speed 90 degreee turns under 20mph. Also heard when starting engine or lesser so when letting out clutch in 1st gear.
Do you hear it when turning left, right or both? when turning either left or right
- is the engine noise correlated to engine speed/RPM? usually at moderate rpm (1500-2000) in 2nd or 3rd gear.
-when you look at the engine, is anything looking different to normal (eg, belt tension? PS Fluid level?) nothing noticed.

Thanks again, Dave

[jjeffries]

The CV joints in driveshafts, when worn, can make a rhythmic clicking when turning. I wonder if the rear wheel bearings could be suspect, too?

Replacing engine mounts could certainly have changed the drivetrain's geometry slightly.

Hopefully others will chime in. Best of luck, John

[djnolan]

It is more of a gouging or grating sound then a Thump Thump and it occurs anytime the suspension deflects up or down. I'm beginning to think the transaxle mount may be damaged.