407 HDi misfiring and juddering?!

[shaunreeves]

Hi, I'm new to this forum and I'm looking for an answer to a problem that is giving me a great headache! My 2007 407sw HDi 2.0 SE started juddering during acceleration and gear changes generally from 2nd to 3rd about 6 months ago. I took it in for a full service as it was due and had all filters changed and oil. Misfired and juddered when I le the garage but then was fine shortly after.

For about two weeks after it has been like a new car, problem solved I thought, maybe the filters just needed changing. But then at least once every other journey it would misfire/judder as if there is lack of power for a split second. Today (11/12/2011) it has just gone back to its old annoying ways again.

Misfiring almost every few minutes, through most gear changes and for no apparent reason when at traffic lights. There seems to be no rhym or reason to it in order to point point the cause.

Could anyone shed light on this from a previous experience please?

Kind regards,

Shaun.

[danthevan]

For the sake of a few quid, i'd get the filter changed again. If it cures it again, then i'd say you've got some contaminated fuel in there

[Gibbo]

I've read on other forums of 407 owners having a similar problem when replacing the fuel filter. I had it myself, I disconnected it, refitted and primed the system.

[CAB]

I'd have a look at the fuel filter first and if it doesn't improve I'd think about getting it hooked up to peugeot planet to see what egr valve and dpf look like.

Does the car mainly have short journeys round town or good blasts down motorway?

Cris.

[shaunreeves]

The car has dual journey types. Round town and 60mph dual carriage way blasts 5 days a week to and from work. I only had the fuel filter changed in a full service in the last two weeks, would this be covered in anyway? Obviously this is relative the the garage, but I will check.

Even though there is no warning lights on the dash will an error or feedback be given if hooked up to a computer?

I relation to the top comment regarding "contaminated fuel" could this happen even from my local tesco station? And if so how?

I'm very great full for the speedy responses and very keen to find a resolution to this very annoying scenario with so many possibilities.

Thank you.

[danthevan]

If you have water in the diesel / contaminated fuel, then that's down to you unfortunately. But for the sake of a few quid for a filter, and the fact it behaved last time it was done, that would be my first route to try.

[CAB]

Egr faults don't always show as a warning on the dash/mfd but if there is a fault planet will find it.

[shaunreeves]

I've just had Green Flag out and they plugged in their computer giving an error for the CRANK POSITION SENSOR. Apparently there is fluctuating currency going through it and this measures the teeth on the fly wheel which in turn tells the pistons/valves (or something, not a mechanic!) to open. Due to there not being the correct currency consistently through the sensor the valves/pistons are not firing correctly and this is causing the misfiring/juddering. An news sensor is (apparently) between £20-£50 (plus labour). I'll get this do at a friends garage as this can be done cheaper.

According to the engineer it is usually located under the engine hence why it was worse in wet weather.

I've heard many things over the past few months and I'm willing to try any of these. I'll keep in mind trying to keep clean fuel and the filter and thank you for your suggestions.

I'll let you know how I get on and if this case can be closed!!

Thanks, Shaun.

[danthevan]

Nice easy fix if it is the crank sensor

[fhmboy]

Originally Posted by danthevan

Nice easy fix if it is the crank sensor

Any ideas or pics as to where this sensor is as im having similar probs, misfire at 1500 rpm then ok very annoying as i cant race the corsa boys any more