the 1500rpm shudder?

[BobRonk]

I've noticed a shudder/miss when driving around 1500rpm on my 2.5 4motion (190K). Really noticeable when holding a constant speed especially in 5th, fine under acceleration.

My initial thought was injector problems and intend to try some LM but I read on another posts that the drive couplings can cause this? Has any one else has this problem and found it was the drive couplings ? (or something else)

Two other things I've recently noticed and now wondering if it's all linked.

Noisey Power Steering
Slight dip in head lights under acceleration.

Any thoughts

Cheers BR

[Silver Caravelle]

Hi BR,

First I suggest ruling out it is not DPF regeneration causing slight lumpy running. Although this would be only for about 20 mins of running in this cycle.
Second I had similar on my 2008 Multivan for quite some time exhibiting the same at about 1500 RPM and reasonant vibration around 1800 RPM. It drove me nuts for a long time. I tried LM but no real change to smooth it out and I went through many other checks to no avail. The last few months, it has been really quite smooth with most of the symptons gone! The only thing I have changed is I amnow buying diesel from my local 7/11 (Mobil). Outside of that I have no clue why it is so much smoother other than the change of fuel supplier. Maybe we underestimate how sensitive to fuel quality these vehicles can be? The slight dip in headlights under acceleration would be worth investigating whether there is a charging issue with the alternator or the battery is on the way out. Cheers, Scott

[Umai Naa!!]

Front engine mount.

You'll need to remove it to inspect.it.properly.

[BobRonk]

thanks for the advice Scott and UN.
Pretty sure it's not a regeneration but possibly bad fuel although I've been filling up at the same supplier for the last few years.
Just filled up and added some LM so will see how it goes.
Didn't consider engine mounts, feels more like an engine miss rather than a knock, almost like you need to change down a gear.
Probably about time to have the engine mounts replaced anyway and will have the drive coupling done too.

anyone else had similar problems
BR

[BobRonk]

I've had no further problem until today and the rough running started again. I changed into 3rd to increase the revs which seemed to help but it felt as though the engine was going to stall. Pulled in for fuel and smelt hot engine. Got going again and engine was running hotter than usual ( I have a watchdog fitted).

So pull over and give it 15 minutes and check coolant, all good so head home. After about 10 minutes of driving the temperature slowly comes back down and even when I turn the engine off it remains 'normal.'

Could this be a regeneration as Scott suggested, would engine temperature be 10-15 degree higher than usual?

Any suggestions?

Thanks BR

[LogicprObe]

I thought the 'Engine' light came on if it was regeneration?