Hi All.

My 2011 mk3 1.6 ti-vct doesn't seem to be running quite as smooth as it used to.

I have just over 55000 miles on the clock. It gets serviced by a Ford main dealer and was last serviced a few months ago. It had new plugs last year and I had the pcm update installed then which made it feel like a new car.

For the last couple of weeks it has been feeling like it stutters a bit accelerating from low revs, especially after slowing right down for traffic and then pulling away again before stopping. I have checked for any error codes in forscan but nothing showing.

I suspected the ignition coil pack and bought a new one which did improve the stuttering but it hasn't gone completely.

Does anyone have any ideas on what I can check? I had a look in forscan but don't know what to look for specifically.

 

Thanks

Check for any splits or softness on the crankshaft breather pipe it's just behind the intake.

Ok thanks, I will have a look tomorrow if it isn't pouring down all day.

Ok I had a look earlier and it looks fine. No softness anywhere and no splits visible.

Does anybody have any ideas what else I can check?

After a bit of researching I had a little run on local roads with traffic about earlier today while forscan was running on my mobile.

I checked long term and short term fuel trim all seemed to be fine, all below +/- 10. I monitored the cylinder timings and checked for misfire.

I got around 4 misfires over a couple of miles on various cylinders and on checking the total misfires I have over 15000 which I guess is from new.

My next thought is just get a set of new spark plugs and see if it improves things. I don't know what brand plugs were fitted last year but I would have thought they would still be ok.

I had a similar issue with mine not long back, it was only a single cylinder though and was a bad rocker cover gasket so I had oil leaking onto the spark plug. Has your MPG gone down?

On 6/17/2019 at 8:38 PM, ColW said:

I got around 4 misfires over a couple of miles on various cylinders

That stacks up with the stuttering when pulling away at low rpm. Opening up a bit from low RPM will give max. pressure in the inlet manifold, so max compression pressure. The voltage needed to make a good spark goes up with the compression pressure, so any problems with plugs, leads or coil pack will cause misfires.

I got a new set of plugs and mine seems to be running fine again. My mpg seems better but I'm off work for 2 weeks now so won't know fully until I'm back to my normal daily driving routine.

The motorcraft plugs I took out that had been fitted last year looked to be gapped high. I haven't measured the gap but from reading about plug choices people were saying 1mm or 1.3mm and these looked higher.

Just an update since I'm back off my holidays.

I've been driving my car for the last few days with none of the stuttering/sluggishness problems occurring. My mpg has gone up quite a bit with mixed roads, some motorway and early morning traffic I'm averaging over 38 mpg whereas previously I was lucky to get 35 mpg.

I was surprised the motorcraft plugs fitted last year only lasted around 12000 miles but I'm happy with the Bosch Super 4 plugs I fitted. I read the reviews and I know they get mixed reviews but they are working fine for me so far.

I have noticed mine loves hot weather and then drives beautifully, between 10 to 20C its pretty nasty, yet above 25 it loves it.... very strange