Hello All, has any members experienced 2019 (68 plate) Focus 1.0 eco boost juddering/vibration/mis-fire when trying to maintain a constant speed around 67 mph in 6th gear and around 58 mph in 5th gear after slowing down from a higher MPH with the flow of traffic?

However, when driven in sport mode the car drives O.K without problem.

The local main Ford dealer has investigated twice under warranty and say the car is O.K and does not have any faults.  Booked in again in 2 weeks time but do not have a confidence in them.  How do I register with Ford U.K that the fault was present before the 3 year warranty expires?

Any advice would be appreciated.

Thanks Rich

Are you sure it’s not just the cylinder deactivation you are hearing? Sport mode turns it off. 

Hello Alex,  I have just finished reading the cylinder deactivation thread and suspect it could be. I think at 67 mph in 6th gear I should not have change down to 5th gear to avoid a vibration.  

This is my 5th Ford car but I am regretting buying this one, I can only hope Ford will release a firmware upgrade to disable  cylinder deactivation. 

 

 

Should I register with Ford U.K that I not satisfied with this vibration/fault before the 3 year warranty expires, in the hope a firmware fix is available in the future?

I'm still amazed that 666cc is enough to drag a Focus along the road never mind having a few vibrations. I guess the next step will be to switch of the engine completely and just power the car along with the 12 volt starter.

 

It takes a surprisingly small amount of torque to maintain 70mph on the flat.  

It's also technically less than 666cc at that point because of the stratified injection not wasting the entire cylinder full of air under low load...

1 hour ago, TomsFocus said:

It's also technically less than 666cc at that point because of the stratified injection not wasting the entire cylinder full of air under low load...

How does that work?

I just assumed for simplicity that each cylinder would be 333cc and that since two of them were still in use then the actual power would be 2 x 333 = 666cc with the third cylinder being effectively dead and not producing any power.

25 minutes ago, unofix said:

How does that work?

I just assumed for simplicity that each cylinder would be 333cc and that since two of them were still in use then the actual power would be 2 x 333 = 666cc with the third cylinder being effectively dead and not producing any power.

I couldn't get my head around what Tom was meaning either, other than at small and steady Throttle openings,  which is when Deactivation occurs, the engine has to work hard to suck air through the small Throttle opening. When Cylinder 1 is deactivated, its valves stay closed and presumably the fuelling for the other 2 cylinders is changed, but that extra fuelling is compensated for by the the pumping losses being less. When you put your foot down there are less pumping losses because the Throttle is open further, so no advantage in deactivating one cylinder. That is why Diesel engines don't have it, they are not throttled.

That may be nonsense but it is my understanding.

In real life Deactivation is not active for very long, or should I say it goes on and off all the time because the even slightest twitch of your right foot either way cancels it until the Accelerator is steady again and at a small opening. If you drove somewhere with no or an even gradient and there was no other traffic on the road it would stay Deactivated for longer but where I live we don't have that luxury.     

4 minutes ago, Tizer said:

When Cylinder 1 is deactivated, its valves stay closed

I have no idea how cylinder deactivation operates, but surely the exhaust port must remain open otherwise it would be trying to compress the air in the cylinder which would be counter productive ?

1 minute ago, unofix said:

I have no idea how cylinder deactivation operates, but surely the exhaust port must remain open otherwise it would be trying to compress the air in the cylinder which would be counter productive ?

There is a Solenoid that opens and forces Oil pressure to move the Valve Rockers on Cylinder one so that the Camshaft does not press them down to open the Valves.

Both Valves are kept closed so that there is still some heat generated and to keep the engine in balance because there will be some spring effect, which you wouldn't get if the Exhaust Valve was open, and it is timed so that there is a full Cylinder of air presumably without fuel for that one stroke.

The relative lack of heat in Cylinder one compared to the other two has always been my worry if it stayed Deactivated for too long, which is why I sometimes move my right foot on the odd occasion that I have a clear and flat road. Maybe there is a complicated algorithm to take this into account, I don't know.    

Thanks for that info John. I really must spend some time looking at how it works but to honest when I don't believe in something I find it hard to study.

12 minutes ago, unofix said:

Thanks for that info John. I really must spend some time looking at how it works but to honest when I don't believe in something I find it hard to study.

Yeah, I know what you mean, I only started looking into it because my car has it and I like to understand things that are new to me, plus with the FORScan phone app it is so easy to live monitor that and a lot of other things for future reference for when things go wrong with my car. 

Plus there is not much else to do until this pandemic is over and I can get my social life back.  

12 hours ago, unofix said:

How does that work?

I just assumed for simplicity that each cylinder would be 333cc and that since two of them were still in use then the actual power would be 2 x 333 = 666cc with the third cylinder being effectively dead and not producing any power.

In physical terms that's correct.  But direct injection allows a stratified charge method which is where a good chunk of the fuel saving comes from, separately from the cylinder deactivation.

In a conventional petrol engine you just dump fuel into the cylinder using a calculation for the entire cylinder full of air, the whole lot is squashed and 'bang'...  With a stratified charge the fuel is aimed directly towards the spark plug, meaning you're not wasting so much fuel around the edges.  The air around the edges is effectively 'unused' during combustion so less than 333cc per cylinder.  Of course, by that logic you could also argue that the 1.0EB technically uses more than 999cc when the turbo is boosting...