Hi everyone,
I recently bought my neighbor's '86 325es with ~230k miles (odometer broke at 220k lol) that he had bought new and I have since been refreshing every mechanical part of it. I am from SoCal but go to school in Berkeley, so I road-tripped it the 370 miles there a few weeks ago and then drove back down to SoCal last week. Everything was fine until I encountered traffic on the freeway coming back. I went to downshift from fourth to third and got a horrible but brief grinding from the transmission. From then on, I've had strange clutch issues.
Taking off in first is normal, but shifting into second is very sudden and violent, almost as though I'm physically disengaging the clutch to get it out of first and into second. Third, fourth, and fifth are fine.
I'll lay out the series of events: I'm sitting at a red light and it goes green. Clutch in, shift into first, take off. Clutch in, unintentionally bang it into second, the car jerks a bit as I let the clutch out. Clutch in, shift into third fine. Now, I'm coming up to the street I need to turn on, so I brake, clutch in, take it out of third and reach for second, but nothings there, like its "locked out", can't get into first either, but I can still shift it back into third or even fourth. It's not like I can shift it into those lower gears and it feels like neutral, it's like there's a wall blocking the shifter from choosing the gears.
Here's where I think I found the source of my issue: following this sequence of events where I'm coasting to a stop with the clutch in, as soon as I come to a stop with the clutch still in, 1st and 2nd are suddenly "unlocked." Also, if I coast with in neutral, but then release and then press the clutch again, the gears unlock then too. This leads me to believe either the slave cylinder or master cylinder failed and are no longer providing enough pressure to disengage the clutch, the hydraulic clutch fluid is low, or maybe even I was leaking/low on transmission fluid.
I first went to replace the transmission fluid, to eliminate an easy culprit, and after pulling the drain plug, the oil that drained was black and the magnet on the plug was covered in quite a bit of sludge. I looked away for no longer than a minute to clean the plug and when I checked back on it, it was done draining, not even a dribble left. It's possible the fluid was low but since refilling it with fresh fluid, the issue persists.
Then, I decided to flush and refill the brake/clutch system since they share a common reservoir and the fluid wasn't great looking. All the brakes bled fine and the fluid that was flushed out was the color of maple syrup. When I went under the car to bleed the clutch slave cylinder, the fluid that came out was a super dark black and sounded crunchy, as though it was full of sand or something. That gave me hope that maybe it was as simple as bad hydraulic fluid, but it's turning out not to be the case. While bleeding it, there seemed to be an unusually high amount of air that was coming out with the fluid, but after bleeding it a few more times, the pedal felt normal and the fluid coming out was clean.
I took it for a drive and the issue is still there, although it feels marginally better with these new fluids.
Some other relevant information:
Leave any questions you feel I've left unanswered and I look forward to hearing from you guys!
Thanks!
Hugo
I recently bought my neighbor's '86 325es with ~230k miles (odometer broke at 220k lol) that he had bought new and I have since been refreshing every mechanical part of it. I am from SoCal but go to school in Berkeley, so I road-tripped it the 370 miles there a few weeks ago and then drove back down to SoCal last week. Everything was fine until I encountered traffic on the freeway coming back. I went to downshift from fourth to third and got a horrible but brief grinding from the transmission. From then on, I've had strange clutch issues.
Taking off in first is normal, but shifting into second is very sudden and violent, almost as though I'm physically disengaging the clutch to get it out of first and into second. Third, fourth, and fifth are fine.
I'll lay out the series of events: I'm sitting at a red light and it goes green. Clutch in, shift into first, take off. Clutch in, unintentionally bang it into second, the car jerks a bit as I let the clutch out. Clutch in, shift into third fine. Now, I'm coming up to the street I need to turn on, so I brake, clutch in, take it out of third and reach for second, but nothings there, like its "locked out", can't get into first either, but I can still shift it back into third or even fourth. It's not like I can shift it into those lower gears and it feels like neutral, it's like there's a wall blocking the shifter from choosing the gears.
Here's where I think I found the source of my issue: following this sequence of events where I'm coasting to a stop with the clutch in, as soon as I come to a stop with the clutch still in, 1st and 2nd are suddenly "unlocked." Also, if I coast with in neutral, but then release and then press the clutch again, the gears unlock then too. This leads me to believe either the slave cylinder or master cylinder failed and are no longer providing enough pressure to disengage the clutch, the hydraulic clutch fluid is low, or maybe even I was leaking/low on transmission fluid.
I first went to replace the transmission fluid, to eliminate an easy culprit, and after pulling the drain plug, the oil that drained was black and the magnet on the plug was covered in quite a bit of sludge. I looked away for no longer than a minute to clean the plug and when I checked back on it, it was done draining, not even a dribble left. It's possible the fluid was low but since refilling it with fresh fluid, the issue persists.
Then, I decided to flush and refill the brake/clutch system since they share a common reservoir and the fluid wasn't great looking. All the brakes bled fine and the fluid that was flushed out was the color of maple syrup. When I went under the car to bleed the clutch slave cylinder, the fluid that came out was a super dark black and sounded crunchy, as though it was full of sand or something. That gave me hope that maybe it was as simple as bad hydraulic fluid, but it's turning out not to be the case. While bleeding it, there seemed to be an unusually high amount of air that was coming out with the fluid, but after bleeding it a few more times, the pedal felt normal and the fluid coming out was clean.
I took it for a drive and the issue is still there, although it feels marginally better with these new fluids.
Some other relevant information:
- According to the service records, the last time the clutch and slave cylinder were replaced was in '02 at 162k miles. As aforementioned, the odometer stopped working at 220k within the last year so the car is at around 230k miles.
- I am kind of new to driving stick so it is very possible that since I'm driving differently than the previous owner that I stressed components on their way out and caused the failure, but this car has had lots of issues (possible vacuum leak causing a poor idle and throttle response issues, failure to keep up routine maintenance, etc.) so I'm not super certain if the car behaves a certain way because of how I'm driving or because of an issue it's had for a while.
- The slave cylinder is bone dry on the outside with no indication it has ever been leaking.
- I didn't remove it from the transmission to bleed it like I've read online, but bent the tube I attached to the bleeder up so that no air would be forced back in, and made sure of such.
- The previous owner put less than 20k miles on the car in the last 10 years and has only really done slow city driving, to the best of my knowledge, whereas I've been on the freeway, etc. and most likely shifting more aggressively/inexperiencedly (is that a word lol) than him.
- Again, possibly due to my relative inexperience, but the car will sometimes jerk after what felt like a smooth shift.
- It also jerks forward (like aggressive engine braking or something) when lifting off the gas, but I'm not sure if that's a manual car thing, old car thing, or if it's another symptom of my issue here.
- Does this issue sound like a failed slave cylinder? Clutch master cylinder maybe?
- Is it worth rebleeding the slave cylinder to see if the large amount of air coming out was in fact a huge bubble and maybe there's more?
- Not confident on this one, but is it possible I need a new clutch?
Leave any questions you feel I've left unanswered and I look forward to hearing from you guys!
Thanks!
Hugo
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