Clutch pedal vibrates while resting my foot on it (pedal fully out)

[TheIronGiant]

I've been bitching about my lolomatic BMW convertible for a long time, and I finally found a decent 5-speed in my area that's up for sale. I test drove it tonight, and she drives FUCKING FAST and the suspension is very stiff and solid and the shifting is oh so smooth. This is a 1988 BMW 325i Convertible, M20 engine with a 5-speed Getrag 260. 170k on the clock.

I'd buy the car as it is right now...except there is one small problem: as I rest my foot on the clutch pedal (in or out of gear), it vibrates in time with the engine. The faster the engine is going, the faster the pedal vibrates.

Engaging first gear from rest is a monstrously difficult task, because I have to press the clutch pedal really fucking hard, and if I fail to press it 100% then it pops out of first. It will not do this in second gear, however, and neither will it happen from a rolling start.

Once the car is moving, shifting feels normal. I don't have to mash the pedal to go from gear to gear, and the clutch was really freaking smooth. I'd bang on it and the shift from 1>2 was smooth as butter.

The current owner says that it is the master clutch cylinder, and that replacing this part costs about $75. He hasn't the time anymore because he's working at the hospital nearly every day.

Is he on target? Because if it is just the cylinder, I'm going to buy the car. I've always wanted a 5-speed.

[RobertK]

$40.64 at BMAParts.com. This is the one I bought and it works great.

http://www.bmaparts.com/item.wws?mfr=SANYCO&sku=BMW039571&price=40.64&orpartno=1087537&cookieID=1NJ1EKYLB1NJ1ELDYO&drillid=9&image=http%3A%2F%2Fcatimages2%2Esophio%2Ecom%2Fwebapp%2Fwcs%2Fstores%2Fservlet%2Fimc%2Fimages%2Ffull%2F21521156000A%2Ejpg

I'm pretty sure that M20's are matched up with a Getrag 260. The Getrag 240, I thought, was matched up to 4 cyclinders in the 318s but I'm not familiar with convertables so I could be wrong.

I've never experinced the problem you're describing but I would get a mechanic or an experience friend to look it over just to be sure.

[TheIronGiant]

Thanks, I'll check that out.
In the meantime, any other ideas?

[euro3]

Sounds like the fork against the trans shaft

I had the same problem (nasty vibration) and it was nothing to do with the hydraulic cylinder. It turned out to be a cheap part, but I had to drop the tranny to replace it. The fork that pushes the throw out bearing pivots on a little rubber bushing on one side and rests on the hydraulic cylinder on the other. My rubber bushing broke and the fork slid down resting along the transmission shaft causing the spinning motion of the transmission to be felt in the clutch pedal. I dont know if this is your problem, but its worth looking into. Good Luck!

[Julien]

most probably the 1st gear synchro is bad or the throwout bearing is bad.. or both.



Julien

[AndrewBird]

most probably the 1st gear synchro is bad or the throwout bearing is bad.. or both.

I was also thinking the throw-out bearing, but with the clutch pedal having to be 100% in, I would think the master cylinder.

Have you done something as simple as check the fluid in the reservoir?