P38 BMW Diesel Lumpy Tickover

rrdiver said:

Hi guys! This morning I am aching all over! Yesterday changed the Dual Mass Flywheel and clutch assembly on the P38 2.5 DSE. Made up a 220 mm high adapter bracket to fit the trolly jack to the gearbox bracket holes and put the car onto four ramps. Disconnected battery negative within 30 seconds of switching off ignition and left the key in the barrel - no sync was needed on reconnection. Started at 0800 hrs and didn't finish until midnight. Having a friend help made the job much easier as the gearbox/transmission is a big lump to manipulate back in. I have taken a short video clip of the old and new flywheels and will put it onto U-tube in due course. The old DMF (OEM part) was made by LUK as is the new one - they have the same part numbers, so the price saving through buying from a LUK distributor was around £200. (Stuff LR prices!) Anyway, having done it, I am glad to say that the old flywheel was definitely faulty with 4 times the free play of the new one along with sticking and now that the new one is fitted, the fault is completely gone! The car is a delight to drive once again and the strange mis-fire stutter when stopped with a hot engine is no longer there. I should add that this fault drove me around the bend for two years as various 'improvements' reduced the problem, including increasing tick-over speed and even making a small electronic circuit to modify the fuelling. In the end it kept coming back and has now been conclusively proven to be a faulty DMF.

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rrdiver said:

Hi guys! This morning I am aching all over! Yesterday changed the Dual Mass Flywheel and clutch assembly on the P38 2.5 DSE. Made up a 220 mm high adapter bracket to fit the trolly jack to the gearbox bracket holes and put the car onto four ramps. Disconnected battery negative within 30 seconds of switching off ignition and left the key in the barrel - no sync was needed on reconnection. Started at 0800 hrs and didn't finish until midnight. Having a friend help made the job much easier as the gearbox/transmission is a big lump to manipulate back in. I have taken a short video clip of the old and new flywheels and will put it onto U-tube in due course. The old DMF (OEM part) was made by LUK as is the new one - they have the same part numbers, so the price saving through buying from a LUK distributor was around £200. (Stuff LR prices!) Anyway, having done it, I am glad to say that the old flywheel was definitely faulty with 4 times the free play of the new one along with sticking and now that the new one is fitted, the fault is completely gone! The car is a delight to drive once again and the strange mis-fire stutter when stopped with a hot engine is no longer there. I should add that this fault drove me around the bend for two years as various 'improvements' reduced the problem, including increasing tick-over speed and even making a small electronic circuit to modify the fuelling. In the end it kept coming back and has now been conclusively proven to be a faulty DMF.

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Datatek said:

Are you sure the petrol ones don't have DMF?

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chromiumuk said:

Petrol Ravs don't. Apparently the dmf was fitted because the modern diesels are quite torquey & it helps make for more refined running in manuals. The petrol models are less torquey especially at low revs & a solid flywheel is more than capable of smoothing out its pulses. I know that there are aftermarket people who make solid flywheels for the toyota diesel because it has been such a big problem & apparently they don't sacrifice too much smoothness.

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Datatek said:

They make aftermarket solid flywheels for the Transit diesel too, however they are rumoured to cause crankshaft failure because of the torsional vibration stresses not being absorbed. Volkswagen Transporters also suffer the same DMF problem.

My Tranny had a new DMF at 100k miles.

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Datatek said:

Are you sure the petrol ones don't have DMF?

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