Hi,

I am having an intermittent issue with my 2015 1.6TDCi Focus losing power while driving. This seems to happen randomly for short periods and then the car returns to normal again.When the car is then parked and stopped the fan runs for longer than it should - up to a few of minutes. Engine temperature seems ok from gauge. There are no codes coming up on my OBD2 reader or lights on the dash. When the power comes back on it is instant and when it is lost it is instant. Almost like something is sticking off/on but for the life of me I cant think what it could be.

I checked the intake and outlet coming to/from the turbo and noted there was some oil in there so have changed out the turbo but the problem persists. I have also cleaned the MAF sensor. 

My next line of enquiry was going to be looking at the EGR (maybe in need of a good clean and sticking?) but thought I would look and see if anyone else has had this problem. 

The other thing I was thinking was could this be a faulty relay?

Its rather irritating so any help appreciated.

I had this issue with a brand new one back in 2012, Ford could not diagnose the problem so I rejected the car

Fan running after switch-off on a diesel is almost always a sign of a failed DPF regen.

Thanks for reply.

I have done an in fuel DPF cleaner treatment but that seems to have made no difference. Car gets a good run as wife works about 35 miles from home. I have ordered a more direct spray can DPF cleaner that goes into the probe port on the DPF so will give that a go too. 

It may be that this is causing the fan issues and the DPF is blocked but I am wondering if this is a symptom rather than cause of loss of power issue. The turbo was leaking a bit so it was probably on the way out but I think I got this early though it could have been the cause of the DPF issue. I will also put a cleaner through the egr and see if that helps. I am thinking I may pull the injectors too now to inspect them for sooting up before hand as they are easier to reach than the EGR!

Any more thoughts on this apppreciated. 

On 7/31/2024 at 11:33 AM, hebhack said:

Thanks for reply.

I have done an in fuel DPF cleaner treatment but that seems to have made no difference. Car gets a good run as wife works about 35 miles from home. I have ordered a more direct spray can DPF cleaner that goes into the probe port on the DPF so will give that a go too. 

It may be that this is causing the fan issues and the DPF is blocked but I am wondering if this is a symptom rather than cause of loss of power issue. The turbo was leaking a bit so it was probably on the way out but I think I got this early though it could have been the cause of the DPF issue. I will also put a cleaner through the egr and see if that helps. I am thinking I may pull the injectors too now to inspect them for sooting up before hand as they are easier to reach than the EGR!

Any more thoughts on this apppreciated. 

Hi Hebhack, 

Did you get any further with this issue?

By the sounds of it mine has the exact same problem. Mines is a 1.6 TDCI too. I start to loose power (normally happens when I'm in 6th gear), it'll idle along around 60mph but gradually slow as is I go down the gears and wont let me increase the speed. Then after 1-2mins it seems to restore itself back to full power. If I stop the car straight away once I loose power, turn the ignition off and on again then it fixes itself. It is also similar to your issue in that there are no warning or fault lights appearing on the dash. I had it in with the mechanic and there were no fault codes appearing on the diagnostics either. The mechanic changed the fuel filter and put an additive into the fuel along with a general service (oil, coolant, et.c replaced) but it hasn't made a difference. On my first drive to work (30 miles each way) the morning after being with the mechanic, the same issue of intermittent power failure returned. I haven't had a chance to bring it back to the mechanic so I haven't gotten any further with it. 

I also have the same issue with the fan running after stopping too... It doesn't happen after every trip but I do notice it occurring more after shorter journeys. Hard to tell if the fan and the intermittent power failure are linked or if its just a coincidence as the fan running after stopping seems to a common fault. 

If you've gotten any closer to a solution to yours, I'd be interested to hear about it. 

Thanks!

Were the codes read (Forscan?) when the fault was on?

Switching off and on may clear it so won't give any clues.

If it is DPF related, the cause of blockage needs to be found. DPF  is usually victim not cause. If it is becoming blocked due to the initiating fault it may need to be cleaned after that is solved.

If it has vaporiser plug, that definitely needs checking.

On 6/6/2025 at 2:22 PM, Shearers said:

Were the codes read (Forscan?) when the fault was on?

Switching off and on may clear it so won't give any clues.

If it is DPF related, the cause of blockage needs to be found. DPF  is usually victim not cause. If it is becoming blocked due to the initiating fault it may need to be cleaned after that is solved.

If it has vaporiser plug, that definitely needs checking.

Thanks for the response,

I haven't been in a situation where I've been able to read the faults without turning the car off. Next time the issue occurs, I'll have a look at the faults straight away. I'll post any information I find.