Knowing when a clutch will fail

[JHZR2]

My 91 318i has its original clutch at 140k. Both myself and my brother learned on it, it sees regular use, lots of stop and go, traffic, etc. My 9 mile commute has a ton of lights and a toll, so I do a lot of clutching.

Today for the first time, I felt that as I engaged the clutch, especially first from a stop, that as I hit the clutch point, that I had friction, then not much then slam and I was fully engaged. Not sure if this was really the case, if I was doing something weird or what, but something was noticeable. I've been driving this car for nearly 10 years, so it stood out a bit..

Then, after driving a bit, like so I was warmed up and had used the clutch a bunch of times, it went away. Weird.

Is this a sign of a clutch going? Hitting throttle hard doesn't cause revs to fly up or anything.

Also it went away...

Can a leaking rear main seal get oil on the clutch somehow, causing a slip until it burns off?

Also what are the signs of a master and/or slave cylinder going bad? Can you tell by irregularities in clutch/brake pedal feel or action?

Thanks!!!

 

[fdcg27]

The only problem you'll see with the clutch hydraulics is difficulty getting the clutch to disengage.
The inconsistent engagement you describe could be a hydraulic problem.
When you wrote that the clutch went away, did you mean that you had no drive through the clutch with your foot off the pedal?
If so, this is a sure sign of a failing clutch, and it could leave you by the side of the road with no further warning.
A clutch wil usually slip for some time before finally giving up, but this will not always be the case.
The clutch on our '99 Accord was just fine with no slipping until the day last November when it left my older son by the side of the road with no drive in any gear, after only 142K.
A clutch is pretty cheap to replace, and it should be fairly easy on your RWD BMW. Certainly have the flywheel turned, or repalce it, along with disc, throwout bearing and pressure plate.
A few more dollars spent now will save you agravation down the road.
You don't want to R&R the transmission 2X.

 

[JosephHarmon]

Of course oil will make it slip. It may bahave as burning the oil off and grip/clamp well. The slave cylinder on these cars is troublesome. Bleeding is marginally complicated.

These BMWs don't have much of a rear seal problem.


Clutch drag seems to be more issue. I don't know why.

 

[demarpaint]

If the rear main seal is leaking, and oil gets onto the clutch disk, or flywheel, the clutch will eventually get ruined by the oil. Make sure you replace the rear main seal when you do the clutch job.

OTOH if the clutch is slightly glazed breaking the glaze can cause it to function properly again. You can 'sometimes' break the glaze by holding your foot on the brake, and intentionally stalling the car by letting up on the clutch [in first gear] while holding the brake.

 

[JHZR2]

Originally Posted By: fdcg27

When you wrote that the clutch went away, did you mean that you had no drive through the clutch with your foot off the pedal?


No, not at all. With my foot off the pedal, in gear and driving, no issues whatsoever. Even tried flooring it in different gears to see if I could see some RPM fluctuation to indicate slippage. Nothing.

All I ever noticed was that as I was letting the pedal out, the first few times when I started using the car today, it was as if there was a dead zone, where as Id start letting it out, Id get moving a bit, then as I let the clutch out further, nothing would happen, up until I let it out completely and it would almost lunge forward a bit.

Of course all this happens in about 1 cm of pedal travel. But it was different than usual.

Drove the car about 30 miles today, after the first 5 or so, it didnt happen again all day!

 

[rg200amp]

Originally Posted By: JHZR2
My 91 318i has its original clutch at 140k. Both myself and my brother learned on it, it sees regular use, lots of stop and go, traffic, etc. My 9 mile commute has a ton of lights and a toll, so I do a lot of clutching.

Today for the first time, I felt that as I engaged the clutch, especially first from a stop, that as I hit the clutch point, that I had friction, then not much then slam and I was fully engaged. Not sure if this was really the case, if I was doing something weird or what, but something was noticeable. I've been driving this car for nearly 10 years, so it stood out a bit..

Then, after driving a bit, like so I was warmed up and had used the clutch a bunch of times, it went away. Weird.

Is this a sign of a clutch going? Hitting throttle hard doesn't cause revs to fly up or anything.

Also it went away...

Can a leaking rear main seal get oil on the clutch somehow, causing a slip until it burns off?

Also what are the signs of a master and/or slave cylinder going bad? Can you tell by irregularities in clutch/brake pedal feel or action?

Thanks!!!



One easy and quick way to see if a clutch is going bad and not gripping like it should is to do the following:

Have your car in a clear street/parking lot with nothing infront of you. Then, press the brake pedal hard.

Now, press the clutch pedal in and put it in first gear.

Now. Without pressing the gas pedal and while holding the brake pedal SLOWLY take your foot off the clutch. Once it starts catching, slow your foot even more. If you can get your foot totally off the clutch pedal and the car does not stall, your clutch is slipping and needs to be replaced. A good clutch will have enough grip to lock the engine to the trans and force the engine to stall in that situation.

Hope that helps!!!

 

[JHZR2]

It definitely will stall the car...

 

[calvin1]

I don't know how much of my experience with a V8 E34 applies to your I4 E30 but I my clutch is a lot more grabby when the flywheel is cold. This is definitely noticeable on cold mornings before either the engine heat soak or clutch friction has had a chance to work. I've even felt it to a lesser extent getting off the interstate after a long run in 5th.

 

[mechtech2]

An odd thing...
Burned oil on a clutch or brake shoes will actually make it stick and grab, not slip.
Lots of things in the system can be right or wrong!
So you can start gathering parts or clutch repair pricing, if you wish.
There does not seem to be an imminent need to change it now.

 

[nleksan]

I continue to be amazed at how long BMW clutches last! Over 150k on my 325i and the original clutch is going strong with.zero slip. I removed the clutch delay valve and have a Rogue Engineering Stainless Steel Clutch line and Reinforced Transmission Mounts (and Jumbo Clutch Stop, under the pedal), but otherwise the clutch has not been touched (except I guess for fluid changes).
When it does go, it will be treated to a UUC 10lb flywheel, Throw-Out Bearing, and one of the new Rogue Engineering Ultra-Light E34 M5 Organic Clutches (they take an OE M5 clutch and replace/modify the housing and other parts to remove 50% of the weight yet increase strength by 200%, apparently, while leaving the contact material as-is).

With a 1991 318 (i or is?) you have an "E30 M3-Lite", so parts are everywhere on the aftermarket for if/when it finally does go out. I would be more than happy to help you find a great deal on a replacement!

 

[ltslimjim]

I had to get the clutch replaced on our Civic at 258,000 or so. The original. Was slipping often under heavy load; like when vtec wanted to engage the engine would star to over-rev(as if in neutral almost) when too much torque was given(disc slip).

Nearly 3,000 miles in on this replacement EXEDY and it's all good. Just had the OE flywheel re-surfaced, the rear main seal replaced while it was apart, too. I'm having the clutch's master cylinder replaced tomorrow. Small internal pressure drop/external leak at the pedal.