MK3 2.0 TDCI 140 - Missing, hesitancy, flat spots

[vibeone]

Plenty online about this but not for a mk3.  Just wanted to run a few things past you guys....

Car's done 85k, 50 with me.  Never had anything engine related wrong with it, and semi regularly serviced by Ford but only the older vehicles service (oil and filter, pollen or air).

Done about 600 miles at the weekend, about 100 in I felt a series of misses under acceleration in 5th or 6th on the motorway.  Pulled into lane 1 and got my bearings and everything seemed fine, so carried on.  It's missed quite a few times since, usually under acceleration and is generally a bit crap - flat spots, not smooth with the power.  It's also done 500 miles since, and has no codes at all, no warnings etc.

This leads me to believe it could be the fuel filter - which may not have ever been changed, or at least not for 50k.  Could maybe be the HP fuel pump, but I would have expected a bigger disaster than what I currently have.

The car also, and has always, regened the DPF seemingly very regularly - so could this also be that a clean is required - do the DPF cleaners actually work?

Turbo pipes seem ok, and no whistling.  Could be injector related (yikes) and I'll stick some cleaned in there too, any other cheap fixes I can try?

Thanks!

[FatHead1979]

On 7/22/2019 at 9:55 AM, vibeone said:

Plenty online about this but not for a mk3.  Just wanted to run a few things past you guys....

Car's done 85k, 50 with me.  Never had anything engine related wrong with it, and semi regularly serviced by Ford but only the older vehicles service (oil and filter, pollen or air).

Done about 600 miles at the weekend, about 100 in I felt a series of misses under acceleration in 5th or 6th on the motorway.  Pulled into lane 1 and got my bearings and everything seemed fine, so carried on.  It's missed quite a few times since, usually under acceleration and is generally a bit crap - flat spots, not smooth with the power.  It's also done 500 miles since, and has no codes at all, no warnings etc.

This leads me to believe it could be the fuel filter - which may not have ever been changed, or at least not for 50k.  Could maybe be the HP fuel pump, but I would have expected a bigger disaster than what I currently have.

The car also, and has always, regened the DPF seemingly very regularly - so could this also be that a clean is required - do the DPF cleaners actually work?

Turbo pipes seem ok, and no whistling.  Could be injector related (yikes) and I'll stick some cleaned in there too, any other cheap fixes I can try?

Thanks!

I'd start of with the fuel filter mate, common rail diesels (i.e. modern diesels) REALLY do NOT like a clogged filter.  A number of people have posted on here with similar problems and have resolved them by changing the fuel filter.  Even if it isn't the root cause, it'll be well and truly ready for being replaced so at least it's done for the future.

[vibeone]

On 7/24/2019 at 8:21 AM, 1979Damian said:

I'd start of with the fuel filter mate, common rail diesels (i.e. modern diesels) REALLY do NOT like a clogged filter.  A number of people have posted on here with similar problems and have resolved them by changing the fuel filter.  Even if it isn't the root cause, it'll be well and truly ready for being replaced so at least it's done for the future.

Slightly random response, but I wanted to say thanks - not sure how I missed the original reply.  I had considered the fuel filter, and it would be very much due.

However, since then I'm now in the process of trading it in, so hopefully my new focus will be spot on!

[Phil21185]

I remember not long after an oil change only, cold weather and a nearly empty fuel tank and I had this, but I did get warning and error messages. 

New fuel filter and it's been fine ever since.

Pretty easy to do yourself too, if you have a priming bulb.