Knocking on acceleration and deceleration

[PeteZ3]

So since having the zed back on the road and with the hood up because of this rubbish weather were having!

But with the hood up I have noticed a knocking noise that occurs on initial acceleration and deceleration, it is almost like there is a slight delay when engaging accelation, which leads me to believe it is diff related or drive shaft related.

Ill try to explain it better..... basically, when you are engaged in gear (it seems to be worse in lower gears, probably because everything spins faster "i think") and come off the clutch it makes a knock, but when you are on the power it is fine, and when i let off the power it makes a knocking sound, it sounds like its underneath me, central to the car.

Ill also add that the move 'violently' i get on or off the power the noise is louder, which makes me think that its drivetrain related

so id basically like to know what too check so that i can replace what needs replacing. diagrams or pictures would be very helpful as im not that well up on vehicle part names.

ive been busy with a new job and other things so sorry for not updating my other thread with pics! if the weather stops being crappy ill give the zed a wash ans snap some pictures this weekend!!! i promise!!

Pete

 

[Antm72]

Is your car a 2.8 ? This has been mentioned a few times here and the clunck is drive train related but nearly all 2.8's appear to have it .
Louder when cold more in 1st and second and definatly in sharp gear change at least on mine.
So many things that can cause it but never read about a difinitive fix it appears to be a common trait.
No doubt others will give advise just my experience.

 

[PeteZ3]

Is your car a 2.8 ? This has been mentioned a few times here and the clunck is drive train related but nearly all 2.8's appear to have it .
Louder when cold more in 1st and second and definatly in sharp gear change at least on mine.
So many things that can cause it but never read about a difinitive fix it appears to be a common trait.
No doubt others will give advise just my experience.

yeah, its a 2.8. is it a bad thing? or is it just a character of the car and not worth worrying about?

i cant hear it when the tops down so its not like its very loud, its just when the tops up, love the note the exhaust gives off just under 2000rpm though!! ....

 

[Antm72]

I believe its a character thing.
I have been under mine and looked and felt for play.
Drive shafts move diff instantly both sides input to output. The play is in the propshaft on mine and the cluck is the car taking up drive, this can be virtually removed by driving style and i found once your aware of it you live with it and drive to remove it.
Worth checking the car over.
Can be diff bush, guibo related and worth checking where it appears to originate on your car for piece of mind, but i imagine as said its a characteristic of the car.

 

[Antm72]

Only thing here is you get noise on de acceleration that i don't have only on take up rather than let off.

 

[PeteZ3]

I believe its a character thing.
I have been under mine and looked and felt for play.
Drive shafts move diff instantly both sides input to output. The play is in the propshaft on mine and the cluck is the car taking up drive, this can be virtually removed by driving style and i found once your aware of it you live with it and drive to remove it.
Worth checking the car over.
Can be diff bush, guibo related and worth checking where it appears to originate on your car for piece of mind, but i imagine as said its a characteristic of the car.

cheers, well thats a bit of peace of mind, yeah, well ive been underneath a couple of times and i have actually had a go at moving the drive shaft and it does have a bit of rotational play in it, so thats what im guessing it is, i had read that that is normal, but if thats where the knock is coming from then thats that i guess!

but i agree with you i have changed the way i drive it, just easing into acceleration a little bit and coming off the clutch slightly slower, im living with it, and hopefully i get better at driving it! not the easiest car to drive since im used to driving a diesel ford fiesta.

 

[PeteZ3]

Only thing here is you get noise on de acceleration that i don't have only on take up rather than let off.

its hardly anything, maybe mine has more play than usual....

id still like a bit more input from other members please id like a list of things to check next time im under the car

 

[Bozzy]

My 2.8 has a similar transmission noise but only on"take up".
When i 1st got the car i bothered me until i found it does seem to be a common thing on 2.8's.
I read some where that it occurs after about 30k miles or so and there doesn't as @Antm72 said seem to be a definitive cure
I found that not dipping the clutch too far seems to help when changing gears and not changing too fast helps as well,which is a shame as it's a sports car (for me at least).
Wonder if the 3.0 are affected in the same way ?
At the end of the day i hope it doesn't put you off what is a great fun little 2 seater,i Love mine .


Steve.

 

[PeteZ3]

My 2.8 has a similar transmission noise but only on"take up".
When i 1st got the car i bothered me until i found it does seem to be a common thing on 2.8's.
I read some where that it occurs after about 30k miles or so and there doesn't as @Antm72 said seem to be a definitive cure
I found that not dipping the clutch too far seems to help when changing gears and not changing too fast helps as well,which is a shame as it's a sports car (for me at least).
Wonder if the 3.0 are affected in the same way ?
At the end of the day i hope it doesn't put you off what is a great fun little 2 seater,i Love mine .


Steve.

not a chance it will put me off! if you knew how many hours of work i have into my zed you would know how much i love it with time im sure ill figure iit out and work out how to get around the noise. and yes it is a bit of a shame, it wont put me off driving fast though

ill have a go at not dipping the clutch too far, see what that gets me

 

[PeteZ3]

just to add, my zed reached 120K miles yesterday, so its welllll past the 30k mark hah!

 

[Antm72]

I have read that a clutch stop at about a tenner can improve this as @Bozzy has said it improves with not pressing the clutch so far down.
I presume its because you can set it just below bite so that you know more about where the bite is , the free travel to bite is the bit that causes the clunk as it is the slack remove the slack and eliviate the clunk.
There are good reviews on the e36 forums for the stopper and its a cheap fix if it does what they say.

 

[PeteZ3]

I have read that a clutch stop at about a tenner can improve this as @Bozzy has said it improves with not pressing the clutch so far down.
I presume its because you can set it just below bite so that you know more about where the bite is , the free travel to bite is the bit that causes the clunk as it is the slack remove the slack and eliviate the clunk.
There are good reviews on the e36 forums for the stopper and its a cheap fix if it does what they say.

ohh ill look into it, there is quite a lot of travel in my clutch from floor to bite, which is why mine might appear worse than yours? cheeers, ill deffo look into that, how does it work? does it literally go behind your clutch peddle? or am i being stupid in saying that? hah

 

[Antm72]

Here is a thread that gives an outline ..
http://f30.bimmerpost.com/forums/showthread.php?t=716178

You can get the part for about 10 here....

 

[PeteZ3]

Here is a thread that gives an outline ..
http://f30.bimmerpost.com/forums/showthread.php?t=716178

You can get the part for about 10 here....
View attachment 24196

excellent, cheers!

 

[Antm72]

The car had a standard stop fitted but its very small this just replaces it you can see in the thread

 

[PeteZ3]

The car had a standard stop fitted but its very small this just replaces it you can see in the thread

yeah i can see, its really simple, ill give it a go, for a tenner it may just be the thing I need!

 

[Antm72]

There are two one push in and one threaded i believe the threaded one is the correct one for the zed the push fit is 2006 onwards.
Have ordered one from the states 10.50 delivered will update when it arrives

 

[PeteZ3]

There are two one push in and one threaded i believe the threaded one is the correct one for the zed the push fit is 2006 onwards.
Have ordered one from the states 10.50 delivered will update when it arrives

nice one, i look forward to see what you think of it

 

[PeteZ3]

There are two one push in and one threaded i believe the threaded one is the correct one for the zed the push fit is 2006 onwards.
Have ordered one from the states 10.50 delivered will update when it arrives

was it this one you went for? http://www.ebay.com/itm/E9X-BMW-CLU...m35ac09578a:m:mpp9Z2UvpcOmmewlt2Cb66A&vxp=mtr

 

[Antm72]

No i brought this one.

It lists for the z3 chassis Same manufacturer but different fitment bolt on rather than push in