Seemingly random Mk3 Diesel juddering problem

[ucof]

Hi all I was hoping that someone could help me with an issue my 61 plate Diesel Mk3 Focus 2.0 TDCI is having.

 

I do roughly 500 miles per week and 99% of the time, I fill up at my local Tesco. Currently on 148k miles. I sit at 60mph with cruise control, but there have been times when I've needed to boot it for an extended period of time. Bought in 2012 as a Ford dealer ex-demo model with 15k miles on the clock.

I've always tried to be good on servicing (as much as I could be budget allowing) and I change the oil as and when it should be. Last MAJOR service was a year and a half ago, but has had interim services and such since then.

 

I first noticed the issue one day accelerating away from the Severn bridge tolls ( 0 -> 70mph as fast as possible, then back down to 60mph where I stay), I think when changing up from 2nd to third and flooring it, the car slowed down as if someone was pressing on the brake. Odd, I thought, but tried again and it took off as per usual.

Forward a couple of weeks and the car has started juddering when gently accelerating or pulling off. I put a bottle of diesel injector cleaner into the tank which seemed to make it a little better. I took it into the local garage who cleared the codes with their code reader and told me to drive until the issue came back and then they would re-read the codes and see what has been stored. I tried that, the issue happened again, took it back, no codes found.

Fuel filter has been replaced now, the old one was black. They believed that it may have been the fuel filter being so dirty that it was starving the car of fuel. (I've also learnt how to change the fuel filter myself so I can do it in the future. Youtube videos were totally different than my engine, so no help there). garage also advised to fill up every third tank with Texaco/Shell/BP.

I drove away happy.

The issue returned, I went back to the garage who suggested that the injectors need looking at.

 

The issue mainly happens after I've driven down the motorway, then stop for 5 minutes to pick my little one up, then try to drive away again. The car will be juddery when accelerating.

I do not believe that the happens from cold, issue only happens when engine is warm and after the engine is re-started. There is absolutely NO smoke that I can see, of any colour, coming out the exhaust under any conditions.

It has also previously been juddery while idling.

One time, the  issue started when driving down the motorway out of the blue - it was very shakey. Definitely engine shake, not wheel balance issue.

Another time, my foot was flat on the floor, in 6th gear and both rev and speedo needles just stayed exactly where they were. No acceleration whatsoever and no judder.

It just seems to be esssentially random as to when it happens.

 

Has anyone got any ideas what could be causing this issue, please?

I dont think that it is the injectors causing the issue, as surely they would cause the problem to happen all the time, as opposed to randomly?

Almost feels like a vapour lock, or something?

 

Thanks in advance!

 

[alexp999]

Might be worth checking to see if it's got the latest PCM update.

I had a lot of issues pulling away in my 2012 2.0 TDCi until they updated the PCM and it pretty well sorted it.

[Jezza54]

My 2012 Focus 1.6 tdci does something similar to what you describe. It always happens at motorway speed though, it's as if the brakes have been gently applied for a split second and then it carries on as normal. It's very random and doesn't happen often. The garage could find no fault code stored. 

I noticed it doesn't happen on tankfulls of BP Ultimate/ Esso Supreme/ Shell V Power.

expensive I know but the car runs much much better. Try it.

[Typhoonf2]

5 minutes ago, Jezza54 said:

My 2012 Focus 1.6 tdci does something similar to what you describe. It always happens at motorway speed though, it's as if the brakes have been gently applied for a split second and then it carries on as normal. It's very random and doesn't happen often. The garage could find no fault code stored. 

I noticed it doesn't happen on tankfulls of BP Ultimate/ Esso Supreme/ Shell V Power.

expensive I know but the car runs much much better. Try it.

that will be the dpf regenerating itself mine does it every couple of weeks on the motorway you should see the temp gauge go up and down for a few minutes until its finished. i use Shell v power and its runs better feels quieter and give more mpg.

[Jezza54]

Ahh thanks for that! Why didn't any of the Ford service departments I asked know that?

[ucof]

Alex - thanks for the suggestion, I'd +1 if I could. There's been no problems in my 5 years of ownership prior to this issue, there's been no updates to any software done AFAIK, so i don't think that could cause the issue.

Jezza - I've tried a full tank of Texaco superior diesel, but its still doing the same stuff. Though not really to the same degree as it was before the fuel filter change. Last night, as expected, drove down the motorway as smooth as butter, stopped for 5 mins to collect my little one from nursery and again, the car started kangerooing upon driving off again. Your issue sounds a little different to mine - mine is far worse than someone gently pressing the brake for a split second. Mine is more like an elephant with a twitch pressing the brake.

 

Could a worn clutch or timing chain cause these issues?

I'm thinking that it's more like to be a sensor, due to the car running fine from cold start, and only having issues when restarting when warm.

[Phil21185]

I read somewhere that in some models you had to let the engine idle for a bit after a long run to let the turbo cool. Apparently funny stuff can happen when the engine is just switched off straight after a drive. Ford fixed this with an ecu remap I think.

I admit I know naff all about engines really so I dont know if it could be yiur problem but I'll see if I can find the thread again.

 on my mk1 the speed sensor was going. Every so often the speedo would drop and acceleration became very jerky until it sorted itself out...

 

[mjt]

10 hours ago, Phil21185 said:

in some models you had to let the engine idle for a bit after a long run to let the turbo cool

The main reason for letting the engine idle for a while is to maintain a pressurised oil supply to the turbo whilst it's spinning down.

[Phil21185]

13 hours ago, mjt said:

The main reason for letting the engine idle for a while is to maintain a pressurised oil supply to the turbo whilst it's spinning down.

Ahh. Could that be the cause of the OPs problem do you think?

[ucof]

Just an update for everyone...

 

Car died totally (foot on floor and NOTHING happening, no revving or response) after a number of errors (Hill start feature not available was one of them!) whilst doing lots of short journeys near my dad's house for Father's day. Still no engine warning light though.
Roadside callout guy detected error codes on all for cylinders (fuel/air mixture inbalance) as well as turbo charger underboost.
Had the car recovered and taken into my local garage.

They took the fuel pump and injectors out and sent them away to be tested.
Everything passed, with no issues found.
Injectors and pump refitted.

Still no error codes and garage cannot get the issue to replicate at all. They've driven it, had it idling all day and "it has not missed a beat". Its been 100% fully reliable for them.
I have the car back and it seems to be behaving in the short time that I have tested it. They've given/ lent me an ODB2 code reader, so that if the issue happens again, I can write down the fault code and then clear codes.
Garage are of the opinion that there was something stuck in the injectors or fuel pump that was pushed out when it was connected to the high pressure test rig. Now the blockage been pushed out, issue shouldn't happen again.
 

If that is the case, then I've learnt just how vitally important it is to change my fuel filter more regularly. I had totally underestimated how dirty it could get, and how expensive (£466 at present) it would be to rectify the possible problem that a big of crud being pushed through the filter would cause. Still, at least im not looking at having to replace the injectors and/or fuel pump at a much, much greater cost.

 

I'll update if I hear anything further.

[drsdriver]

Glad you sorted it, I agree, fuel filters should be replaced every year along with oil and air filter.