Clutch slipping? - BMW Forum

Tochenzo · 02-18-2006, 06:55 PM

Whenever i accelerate in gear (2nd and up), my rpm's go down first and then go back up. Is this due to my clutch slipping or is there another problem? I know my clutch is probably pretty worn out since it's still the original clutch at 80k miles. If it is the clutch, do you guys recommend just switching to an M3 clutch since i'm going to be looking at some major power mods in the future?

BImmerN2B · 02-18-2006, 07:27 PM

I remember reading that BMW has a special tool to check your clutch to see if its worn. Also do the clutch disengage a little higher than usual? That's how I recognized mine was going out. They are suppose to give out at about 100,000 miles. Depending how much spirited driving you do and if you live by a lot of hills may affect that longetivity.

about your clutch, check with Bavauto to see what application they can do for you. But remember, the better the clutch, the faster your tranny might go out and your driveline suffers.

Tochenzo · 02-18-2006, 08:09 PM

To clarify:

some times when i shift to 3rd from 2nd it takes a while for the rpm's to actually increase

also...lets say im in 4th gear cruising, if i step on it all of a sudden, it takes 1-2 seconds before my rpm's actually increase

SpooldUp · 02-18-2006, 08:22 PM

Hmm, if your clutch was slipping, there wouldn't be an rpm DROP before it took off. The rpms just increase faster (proportionaly) than your speed while accelerating. Slipping clutch has an odd burnt dust smell. Notice it?
If it is slipping, take it easy on her untill a replacement can be had. Also check for any oil leaks around the rear seal - this is near the clutch.
I would say if you are noticing slipping and planning power mods then replace the clutch (and pressure plate and Throwout bearing) with a performance version. Maybe 'toss' in a new lighter flywheel as well. Yes this will slip less and shock the driveline more like N2B said. Life is all about tradeoffs.

SHAHAB323IS · 02-18-2006, 08:29 PM

Quote:

Originally Posted by Tochenzo

To clarify:

some times when i shift to 3rd from 2nd it takes a while for the rpm's to actually increase

also...lets say im in 4th gear cruising, if i step on it all of a sudden, it takes 1-2 seconds before my rpm's actually increase

that's normal if you wanted instant acceleration you'd have to downshift from 4th, and when you upshift the rpms are supposed to drop my car has like 117k and the first and previous owner was a woman and i drive it pretty good and the clutch is still fine, good luck

cloaked95 · 02-18-2006, 10:48 PM

I replaced my clutch at 130k. The most obvious way to find out is if you are driving at low speed( ie 30mph ) and upshift to like 4th gear and gun the accelerator, The rpms should shoot up as if its on neutral therefore calling it slipping. The disk is slipping from the pressure plate and not making the transmission accelerate as fast as the engine. Hope that helps.

thekid · 02-18-2006, 10:59 PM

A good way to check is to go to a parking lot or any where else where there is nothing infront of your car. At a stand still put the car into 4th or 5th gear and just take the clutch out without giving it any gas. If the car dies immediately then your clutch is good, if it does not then the clutch is either bad or going bad (just depends on how long it takes the car to die).

Tochenzo · 02-18-2006, 11:00 PM

so if it doesn't shoot up right away if i go to 4th at low speed, that means its not slipping? i'll try that tomorrow

Tochenzo · 02-18-2006, 11:01 PM

actually now that i think about it, when i do gun it in 4th, the rpm's go up first, then back down, sorry i had it mixed up

since my rpm's go up first before it goes down when i shift gears, that should mean that the clutch is slipping and not engaging right away correct? So you guys have any recommendations for clutches?

bob318 · 02-20-2006, 12:33 AM

dude that sounds like a bad idea! hahaha extra slippage is not a good thing.

Redbullrr · 02-20-2006, 08:38 AM

I just replaced my clutch with a factory one. You'll be suprised how good they are. I thought it was going to be weak. But if I take off my traction control, I can get the tires burning on second witch is a nice feeling. LOL

Tochenzo · 02-21-2006, 01:54 PM

i did those tests, here are results

after i shift from 3rd to 4th and i go full throttle, my revs go higher than my speed

when i start my car in 5th, it dies right away

when i shift from 2nd to 5th at 20 mph, my rpm's just drop a lot

so...i guess this means its slipping...but not too much?

bob318 · 02-21-2006, 02:16 PM

i dunno man, your rpms should be higher than your speed if your dipin. and as for starting in 5th im pretty sure everyones car would die. Mine would. and as for 2nd to 5th my car would bog for sure if i shifted from second at 20mph to 5th. Just use your gears man.

Tochenzo · 02-21-2006, 02:33 PM

Quote:

Originally Posted by bob318

i dunno man, your rpms should be higher than your speed if your dipin. and as for starting in 5th im pretty sure everyones car would die. Mine would. and as for 2nd to 5th my car would bog for sure if i shifted from second at 20mph to 5th. Just use your gears man.

yea but i think if your clutch slips then if u ship from 2nd to 5th it would just rev...

thekid · 02-21-2006, 02:54 PM

It sounds more like a timing thing than the clutch slipping. If I do not release the gas all the way while shifting or do too much gas while shifting up then my rpms will rise and then fall as the clutch comes out. Are you sure the rpms continue to rise after the clutch is all the way out and then go down, then back up?

And no, if the clutch is bad then the car will not immediately die, it will sputter and then die. This test was taken directly from a Chiltons Manual for how to test a clutch.