MC Ecoboost engine hesitation/stalling

[steerage250]

Over the last few years, my wife has reported that our MC Mondeo 2.0 Ecoboost very occasionally hesitates when she puts her foot down to pull into, or across traffic - from a standing start. Naturally, this can be a bit nerve-wracking. Usually/always, it is with a cold/cool engine (driving less than 5 minutes).

The other day, she was waiting for a car parking spot to be vacated, then as she went to pull-away from stationary, the engine stalled completely (1st time it has stalled).

I am really reluctant to take it to Ford as the chances of them seeing the fault (either before or after attempting some fix) is extremely unlikely.

I checked for fault codes with ForScan and saw nothing suspicious.

Anyone got any thoughts ?

[fiestaz]

Originally Posted by steerage250

Over the last few years, my wife has reported that our MC Mondeo 2.0 Ecoboost very occasionally hesitates when she puts her foot down to pull into, or across traffic - from a standing start. Naturally, this can be a bit nerve-wracking. Usually/always, it is with a cold/cool engine (driving less than 5 minutes).

The other day, she was waiting for a car parking spot to be vacated, then as she went to pull-away from stationary, the engine stalled completely (1st time it has stalled).

I am really reluctant to take it to Ford as the chances of them seeing the fault (either before or after attempting some fix) is extremely unlikely.

I checked for fault codes with ForScan and saw nothing suspicious.



Anyone got any thoughts ?

I don’t know a lot about turbo engines but my fiesta had similar issues caused by a filthy throttle body and air filter. - Ford could not find this or work it out. Could be a good place to start.

[steerage250]

Originally Posted by fiestaz

I don’t know a lot about turbo engines but my fiesta had similar issues caused by a filthy throttle body and air filter. - Ford could not find this or work it out. Could be a good place to start.

Yes, I have some throttle body cleaner and injector cleaner on my shopping list for next week - can't hurt to try!

[stefcio007]

Clean the Mass Air Flow sensor with the CRC branded stuff if the rest doesn't work.

I'm guessing maybe under low air flow it's not reading properly but when there is heaps of air flowing the small error reading doesn't affect it too much. The sensor is responsible for getting the right air/fuel ratio, but...a dirty one usually just makes it run rich?

Wouldn't hurt to inspect it though. It is very sensitive so don't touch it or use any other cleaning product.

[shiner01]

I had this happen on my 2011 Mondeo 2.0 l SCTI ecoboost Hatchback. Happened when cold and also when warmed up. Could be quite bad and very embarrassing at times. As my car was still under guarantee, I had bought on 1st October 2018, I returned it to dealer, a Main Ford Agent, they had it in for a day and found that the problem was due to an air leak in the connection of the air intake to the airfilter. Since then, which is now about 3 weeks I have had no repeat and the car is running smoothly and accelerates without any problem.

I must admit that I thought that it might have been something more serious as it seemed the engine was suffering some form of fuel starvation as the jerking could be quite bad at times and very embarrasing when trying to accelerate into a gap in the traffic. I thought that it might have been the fuel pressure system at fault but thankfully it wasnt and the dealer did for free. I had no fault codes but on one occasion I did have a yellow warning which said "Engine Malfunction" but no fault code.

[steerage250]

I removed the air flow sensor and gave it a good squirt with CRC CO Cleaner. It wasn't noticeably dirty, but we'll see how it goes.