Over the last 2 years or so I've been occasionally getting an engine warning light and a drop in power. This is usually when I'm going up a hill, possibly in too high a gear. I took the car to a local garage and they said it just needed oil (that was the conclusion they came to after reading the fault code) and it took nearly 5 litres. I thought this was odd, since I always do the recommended services and never had to even top up before. A few months later, it did it again. Around this time, the car had a service at Ford and they noted "leaky VCT valve" so I went back to the local garage and they replaced that. A few months later, it's still doing it and the oil level is fine.

Ford want £100+ to even diagnose it, so I'm asking here first what this is likely to be in case it's a common or obvious fault.

As an aside, every winter I get the "filter full / drive to clean" alert on every journey, short or long.

No mention of the code picked up by garage?
Do you really mean it took 5 LITRES (I suspect impossible, engine would have seized?)
Looks like there's a DPF issue too which could easily cause limp mode?
Save your £100 and get Forscan (free - you MUST have seem the details on here?) and a either lead for Windoze laptop or Bluetooth adapter for phone.
Then check the codes when the problem is actually on (don't switch off, read the codes first as they may clear)
As it looks like a diesel, change the fuel filter unless you are certain it is OK (and you can't be 100% as you don't know it it is a bad batch or you've had some dirty fuel?) If changed, tear it apart to check.
Come back with history and more details! 😉

6 hours ago, jamieburchell said:

and it took nearly 5 litres

Someone's having a laugh 🤣

when I last worked on cars for a living  it was common every third car would come in with almost nothing in it 

the worst that was still running I did, had about 1/2 a litre in it - out of a design spec around 4 litres - but 1.5 litres left, was about average for ones owned by lazy owners / driving company cars....

these days many cars don't use any engine oil between services - but that doesn't have to be the case and I expect plenty driving around vastly lower than recco quantity

the guy saying 5 litres might have been having a bad day, wanted someone to wake up, or was keen to extort more money from a motorist that isn't paying attention to things - but I can well believe he put at least 3 ltres in there

one needs to remember modern cars running on synthetic oil can survive 5 miles with nothing in there - not at all a good idea but modern oil is incredible

 

10 hours ago, Shearers said:

As it looks like a diesel

I can see why you'd say that however diesels don't have VCT.  This must be a petrol with a GPF. 🤔

I suspect it needs a PCM software update to stop the GPF warning in winter.

It's a petrol. I had an argument with a Ford technician years ago about the GPF warning - they swore that it's normal and there is no "software update" for it and that I just need to drive it. I said that I do and surely it shouldn't come on every day when it's cold. They apparently had it running all day and couldn't reproduce the issue. Anyway, I just put up with it every winter.

I'll see if I can dig out the receipt from the local garage for the oil they put in, I have no reason to doubt him. I just remember him saying it just needed oil it was nearly empty to which my response was are you telling me that I get persistent in-car notifications and alerts on my and my wife's phone if the washer fluid is low, but the engine oil light doesn't come on?

I have an OBD Link MX WiFi - I did plug that in the first time it happened but have long since forgotten what it said. I did show it to the garage, but they have their proper OBD scan tools so assumed "it just needed oil".

I'll see if I can find out more. Incidentally, my car is a 1.0 EcoBoost model year 2018 manufactured 2019.

10 hours ago, jamieburchell said:

I did show it to the garage, but they have their proper OBD scan tools so assumed "it just needed oil".

I'll see if I can find out more. Incidentally, my car is a 1.0 EcoBoost model year 2018 manufactured 2019.

A normal garage is unlikely to have Ford specific diagnostics.  Forscan will be far better than whatever generic OBD most local garages use.

As for oil, the 1.0 EcoBoost doesn't even take 5 litres, so hopefully they didn't put that much in.  Have you checked the dipstick since?  It's probably well over max now.

1 hour ago, TomsFocus said:

Have you checked the dipstick since?  It's probably well over max now.

Yes, it's in the middle of the two notches. Maybe the garage charged me for a 5L bottle, but didn't use it all in that case.

Just found the "Pre Scan Vehicle System Report" that the garage gave me: P250F-00 | Engine Oil Level Too Low

I'm still trying to get my old OBD MX WiFi scanner to work and will see what I can find out from it now.

By the way, it's not completely "limp mode" - it just dips like when you turn on the eco drive setting. Everything seems sluggish when that happens. The last time this happened, I had already driven for about 4 hours on a single trip and since that trip I have not seen the "drive to clean" warning.

On 1/5/2026 at 9:23 AM, TomsFocus said:

I can see why you'd say that however diesels don't have VCT. 

I see that now - wish people would put the exact model and petrol/diesel or GPF rather than just filter etc to really describe correctly and give full history (like here) etc for dinosaurs like me (who do try to help!)

On 1/6/2026 at 4:51 PM, Shearers said:

wish people would put the exact model and petrol/diesel or GPF rather than just filter etc to really describe correctly

You're assuming people who post here know about cars. I'm just a Luddite presented with an error message. Thanks for trying to help. I thought my car spec was on my signature, I'll add it now.

having vehicle details in the signature is more problematic than nothing...

because you may be discussing another vehicle and if you don't state that, clever people assume its a different vehicle and everyone heads off on a tangent

any post asking any query on a motoring forum should provide lots of info - specific model - year of production - service history - current mileage - current meddling by fiddly fingers 

I've been waiting for the fault to develop again for months so I could connect my laptop and diagnose it and of course life doesn't work like that and it's happened on holiday.

I did manage to get the attached info but I don't know if someone knows what this means?

Turbo underbooost. Very common fault but several potential causes.

Basically the ECU detects too little air pressure reaching the MAP sensor.

There could be a leak in the air intake piping. Could be a faulty MAP sensor. Could be fault in the vacuum actuator system, not holding the turbo wastegate fully closed. Could be a worn out turbo.

As there are so many possibilities and it takes so long to trigger, you're probably best just continue ignoring it for now.

The oil level still looks OK. A bit worried about the other posts on here with the same (?) issue that mention oil leaking in to the loom and £2K garage bills

2 hours ago, jamieburchell said:

The oil level still looks OK. A bit worried about the other posts on here with the same (?) issue that mention oil leaking in to the loom and £2K garage bills

There isn't 4 litres of oil in the wiring loom. It would look like the Michelin man...

Oil in the wiring loom usually triggers camshaft timing fault codes, not turbo underboost codes? You can check the VCT plugs for oil easily, only takes 10 seconds to unplug them and have a look inside.

I was reading through this thread. The OP describes exactly what leads up to the issue and what happens. https://www.fordownersclub.com/forums/topic/153470-focus-mk4-ecoboost-10-turbo-underboost-fault/

Just got my Focus back from the dealers - new turbocharger, new powertrain control module and wiring loom. Luckily the bill of over £2600 was picked-up by the extended warranty. Apparently something to do with a gasket failing leading to oil leaking into the loom and the PCM

I'll get a mechanic to check the pipes but as you say, could just continue to ignore it.