E30, whats wrong?

[antony 0]

Hey,

Help needed to diagnose a problem.

Car: E30

I went over a speed bump tonight, and directly after my car started making a whirring/grinding sound. When I tried to engine brake (changing down a gear) it started to feel like I was driving on rumble strip.

But, under acceleration, it drives smoothly???

Whats wrong???

Thanks heaps

Antony.

[greenday-rulz21 6]

When you say you went over a speed bump what does that mean? Did the car bottom out, did you hit the front or did it just randomly start once you had made it over the speed bump normally?

[Docile 64]

how fast did you hit the speed bump?

[antony 0]

Really slow over a speed bump normally, like 5km/h if that, didnt bottom out. (Was in car park 200m out on a break water).

[antony 0]

If it helps, my thoughts are;

Clutch/gearbox - Unlikely, due to driveability and it feels like it is coming from the rear. Although Laura said she thinks it was coming from this area.

Centre hanger? bearing - ???

Diff - ???

Rear suspension/trailing arms/sub frame - ???

Anyone expirenced anything similar?

Luckily I have Mondays and Tuesdays off, so hopefully I can get this sorted, not what I was wanting to do during my days off tho.

Thanks

Antony.

[3series 0]

any rattles through the RPM range in neutral? clutch in? clutch out?

[Silver Fox 43]

Guess centre hanger bearing, or rubber guibo behind the gearbox.

[antil33t 90]

When my Center hanger broke (the rubber ripped out)... car was completely fine under acceleration but under any braking (cars auto, so can't really engine brake as easy) it'd go "knock, knock, knock, knock".

Also the Guibo was cracked.

[e30ftw 410]

If it is your center hanger bearing or guibo your car would usually vibrate from the driveshaft shaking, especially under heavy acceleration.

Does it happen as you are releasing the clutch? Could be the thrust bearing come apart..

[323e30 0]

could be as simple as one bolt in the driveshaft missing.

[SIR E30 68]

Possibly a shagged engine mount?

[Carl 3]

No point in speculation, just jack the car up and have a look at the g/box mounts, guibo, driveshaft and centre housing for anything obvious.

[BM WORLD 1280]

No point in speculation, just jack the car up and have a look at the g/box mounts, guibo, driveshaft and centre housing for anything obvious.

plus 1

jack the car up have a good look

[325_driver 422]

man cars never cease to amaze me, i read this both sympathising and rejoicing, because i thought i had problems, those problems you thought no one else in the world had with cars. Keen to know what it was. Reminds me of the story i punctured a tyre on the way out of the place that fixed the same leak.

[antony 0]

So I finally jacked it up...

With both wheels off the ground, I turn one wheel..., the other doesn't move.

Although the drive shaft moves, same deal if I turn the other wheel.

Blown Diff???

Thanks

Antony.

[SIR E30 68]

Is it meant to be an LSD? If its just a normal open-wheel diff the opposite wheel wont turn.

[antony 0]

not LSD.

So the other wheel shouldn't turn in the opposite direction?

[Matty104 0]

im sure open diff means the oppisite wheel turns the other way

Edit, Thats if the driveshaft isnt moving, Two of the 3 components should move

Edited March 8, 2010 by Matty104

[kerry 10]

not LSD.

So the other wheel shouldn't turn in the opposite direction?

sometimes in a open diff one wheel will spin it the opposite direction , if your drive shaft turns when you turn the road wheel i dont think it will be your diff but who knows without actually been there. have you checked if every thing is all tight? if there is something a little loose it may cause it to move after been loaded from accelerating then unloading when decelerating, also have you checked exhaust hangers etc?