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Question about starting from standstill

1K views 8 replies 4 participants last post by  njitram2000 
#1 · (Edited)
I have had my new 116d ED for a week now (600 km so the clutch should be broken in, according to the manual) and I have a problem with pulling away: the engine keeps stalling.
I have been driving manual cars for 10 years and have always used the same technique: apply a small amount of throttle and slowly release the clutch at the same time. Once I feel it "gripping", I apply more throttle and smoothly release the clutch the rest of the way. That has never failed me, even with very short clutches. I tried the same with my BMW and I must have stalled the engine about 20 times in the first 2 days. I can't feel de clutch gripping as well as in any of the other cars and if I understand it correctly, that's because of the CDV but if anything, that should prevent it from stalling, right?

I then put myself on a parking lot to figure out what I was missing and discovered that I had to get the rpm up to 2000 before releasing the clutch, after which the rpm drops to 1500 and then I can get going without issues. Given the delay in throttle response in eco pro and comfort mode, that means I have to be careful to do that everytime I need to get going quickly. The throttle is also very aggressive when the clutch is not engaged, meaning I usually end up around 2500-3000 when I release the clutch, making it more difficult when needing to slowly move forward in traffic (though I'll probably get used to that in time) and causing more wear on the clutch then it should.

I am by no means a professional driver but I'm also definitely not a novice and this is a little bit ridiculous to me. Any insight or tips would be appreciated. Even if this is typical behaviour for a BMW, it would be nice to understand why it's happening.

EDIT: I also noticed that when slowing down, the engine stops running smoothly at a much higher rpm than in other cars Eg. 20km/h in 2nd gear has never been an issue but with this car, I need to shift to 1st because it feels like it's about to stall. This leads me to believe that the flywheel might be lighter than with other cars?
 
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#4 ·
No sorry I can't help,with direct experience other than a three series diesel,I had was the complete opposite of that. Please don't be offended but are you sure it is selecting first gear as sounds like it's pulling away in a higher gear. Like I say not trying to be patronising but just a thought as might be going into third as the linkage may be poorly adjusted or the weighting of the gear leaver makes it sit under third and not first.
Cheers
Jim
 
#5 ·
Hey Jim. No, I'm absolutely certain that I'm in first, if only for the fact that the rpm goes down when I shift to second :)

I also had an idea: apparently, BMWs have a clutch delay valve (CDV) that makes the clutch engage slower than what you're doing with the pedal. I normally let out the clutch until I feel the biting point, then let it grip properly and let the clutch go the rest of the way. That whole process goes very quickly but the biting point is essential. If the CDV causes me to release the clutch too much and then the delayed fluid goes past the biting point, it'll stall the engine because I didn't have the chance to let it grip properly.
I tested this theory and it seems to be correct but it means I have to hold the clutch halfway at the (estimated) real biting point and wait for the CDV to catch up before releasing it the rest of the way. I can't feel it biting, all I notice is that the car is moving smoothly and releasing the rest of the clutch makes no noticeable difference. That's even more awkward than having to apply throttle first and slips the clutch way more, which is not healthy. Then again, this might just be confirmation bias...
 
#6 ·
I can't offer direct help yet. My new 116d ED should arrive later this month so hopefully I won't experience the same issue. I had a weekend test and didn't notice what you describe but the car felt "strange" as I have driven a fiesta diesel every day for around 6 years and 200,000 miles so as you can imagine it has become very familiar.

What I can say is that for all the small capacity diesels I have driven (starting with a 1978 golf LD back in 1983 through many Peugeot 205,309,306 and 405s) in every case you could pull away in first by gently letting the clutch in and leaving your foot completely off the throttle pedal....

First I have heard of a CDV so all I have said may be tosh

John
 
#7 ·
I had experience of the cdv on a five series and it did feel different. In the end I removed it which made the clutch action more direct and linked to the pedal movement. Hopefully letting the dealer drive it might shed some light on your issue. Hope you get it sorted as you have identified clutch life could be short.
Cheers
Jim
 
#8 ·
Something's not right.
I can pull away from standstill without any problems without touching the accelerator in first gear when releasing the clutch slowly, these engines have descent torque at low rpm
You mentioned that you can't feel the clutch gripping normally when pulling away, I can only say that mine feels completely normal and just like any other car, so again I'd say something's not right.
 
#9 ·
I completely forgot about this thread. It took a few months but I figured out exactly what is "wrong" with the car. I put it in quotes because all 1 series are like this (had multiple replacement ones). I thought I'd share it here in case anyone else has the same question.

Firstly, the diesel requires me to pre-rev the engine before releasing the clutch, otherwise it will stall. I have never had to do that with any other car before. It was only when I got a 116i petrol replacement that I realised that BMW had taken the gears from the petrol and reused it for the diesel. The petrol goes throught the exact same rev ranges but because it's more lively, it doesn't trip over itself at very low rpm like the diesel does. The practical solution is to simply to never assume the car will be able to move off immediately and wait for 2000 rpm before releasing the clutch beyond the first light brushing.

Second is the clutch delay valve, which is an absolutely horrible invention. Turns out, it is controlled completely electronically and is "tuned" to your driving behaviour during the breaking in period. I convinced a technician at BMW to reduce the delay significantly and suddenly it drove like a normal car when shifting. It helped with moving off but the first point above still applies.

Third is that the throttle response is also "tuned" to your driving behaviour during the breaking in period. This can be reset by pressing the gas pedal fully (not the clutch), pressing the start button with pedal still down, waiting for a minute (could be less but nobody online really knows for sure), pressing the start button again and releasing the pedal. Now the throttle will be much less lazy.
 
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