My 320d was new in March 2001.
On just two occasions in 21 months, after starting, the engine idled in what can only be described as an 'abnormal' mode - with much vibration (the descriptions 'shaking' or 'oscillating' could well describe it). In this mode the engine did not respond to use of the accelerator. Therefore, I switched off without further delay, and after re-starting, the engine ran normally. I have no clue as to why this occurred - the last occasion was months ago. Could it be that I didn't hold the key in 'start' position for long enough and the engine management system was not 100% operative?
My local BMW dealer was likewise mystified, and failed both to reproduce the effect or suggest a reason.
In all other respects the car has started and run totally reliably.
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I know this sounds ridiculous and I'm sure I'll get told off for giving out stupid information but is there any chance that the engine could have been flung into backwards rotation by high the compression of a rising cylinder and actually began to run backwards? This has happened before in single cylinder diesel engines that I know of but sounds incredible on a new BMW! Will someone please put me out of my misery and let me know if this is at all possible! Matt
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A VW diesel (Passat tdi) I had did this. It was a sticking valve in the exhaust gas recirculating system. However when the car was plugged into the VW garage diagnostic computer the fault showed up even though the fault was intermittent.
Surely BMW must be able to do a similar check?
This probably doesn't help but you never know!
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"Could it be that I didn't hold the key in 'start' position for long enough".
Most diesels require you to keep the key in the "preheat" position long enough for the glow plugs to heat up properly. In some cars this can be up to 10 seconds, but because your 320D is a direct injection diesel it probably only requires a second or two and maybe it only requires even that long in cold weather. (I'm guessing here because I don't know the details of the 320D's start-up procedure!)
Either way, if the glow plugs aren't hot enough the engine won't fire on all cylinders. If it starts at all, it will run roughly and emit black smoke, then usually after a couple seconds it will start to fire on all cylinders and then run normally.
Does this description fit your problem?
Ian
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Matt
This was discussed in www.honestjohn.co.uk/forum/post/index.htm?v=i&t=83...5 and the consensus was that it could only happen on two-stroke engines. The only claim for it happening on a "modern" car was on an Austin Allegro!
Ian
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Hi, just thought I'd contribute. I had this problem on a 2002 Peugoet 406 2.0HDi Common-rail Turbo Diesel (an excellent car & engine). I hired the car for 2 days and at least three times it started as the orginal post described. On all occasions the engine was hot so preheaters weren't needed (I don't drive diesels much but know to look for the preheat warning light but never spotted it even when it was cold), anyway it sounded very very rough and as though it was shaking itself apart - running in reverse is a good way to describe it. If it had been my car I'd have switched it off straight away but the second time it did it I let it 'run' a bit to try and work out what it was doing - most warning lights stayed on (eg oil, ignition, 'STOP' etc) and the rev counter was going up and down very quickly between 0 and 750rpm. I did try revving it and it wouldn't go. It would start immediately and run fine after switching it off. Maybe electrical problem if the lights stayed on, or starter continuing to operate, or the opposite of 'over-run'???? Would be interested in hearing from others as I want to by a HDi 306 very soon.
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I am not familiar with the exact details of this design but the 320d is fitted with a dual mass flywheel. Sometimes with these devices, they can go into a resonance if the engine is not cranked for long enough, with symptoms as described. The answer is to ensure that you keep the starter on for long enough. You should be able to note that the starter will autiomatically stop cranking even though the key is still in the crank position when engine idle speed is established.
Peter F
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