Fiesta ST Forums banner
1 - 19 of 19 Posts

· Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
I have had my MK8.5 since September 2022. I have got a few issues that I am going back to the dealership with but before i do has anybody had the following issues;

1. Interior lights - They have stopped working when doors and boot are opened.
2. Stop/Start has been dreadful since i've had the car. Appreciate its been cold lately but it literally only works once every blue moon. I only really do short journeys aswell.

Not sure about, mentioning last issue to dealer or is it just the downfall owning an ST.
3. Fuel Consumption - Seems to have drastically reduced, when i had got the car averaged 33mpg but now getting 28mpg, even driving carefully (appreciate its winter).

Thanks
 

· Registered
Joined
·
623 Posts
I have had my MK8.5 since September 2022. I have got a few issues that I am going back to the dealership with but before i do has anybody had the following issues;

1. Interior lights - They have stopped working when doors and boot are opened.
2. Stop/Start has been dreadful since i've had the car. Appreciate its been cold lately but it literally only works once every blue moon. I only really do short journeys aswell.

Not sure about, mentioning last issue to dealer or is it just the downfall owning an ST.
3. Fuel Consumption - Seems to have drastically reduced, when i had got the car averaged 33mpg but now getting 28mpg, even driving carefully (appreciate its winter).

Thanks
Fuel consumption, what do you put in it? E5 or E10? how heavy is your right foot? where do you drive.. urban/town/city or motorways? These will all affect your MPG.


As for the lights and stop start it might be the battery, I did see on a Facebook group somewhere that someone had their battery replaced under warranty within a few months as it was faulty so this might be the cause. Do you have any way to test the battery?
 

· Registered
Joined
·
1,668 Posts
Would I be wrong in thinking that stop/start doesn't activate until the car is fully warmed up and up to speed.

If so then if you only do short journeys, especially in these cold dark days with higher drain from lights etc. the opportunities for the battery to be optimum for stop/start is limited.

Wouldn't worry about stop/start unless it doesn't do it in the warmer, brighter months or on longer trips 👍🏻

Personally I press the deactivate button every trip, its not a function I want.
 

· Registered
Joined
·
4 Posts
Discussion Starter · #7 ·
Fuel consumption, what do you put in it? E5 or E10? how heavy is your right foot? where do you drive.. urban/town/city or motorways? These will all affect your MPG.


As for the lights and stop start it might be the battery, I did see on a Facebook group somewhere that someone had their battery replaced under warranty within a few months as it was faulty so this might be the cause. Do you have any way to test the battery?
I generally try to use the good juice when available but recently been using normal fuel. Don't really see a difference in consumption using either fuel. Last few weeks been driving careful due to weather
 

· Registered
Joined
·
1,668 Posts
i have just noticed on the Ford Pass App this morning that it says car is in deep sleep mode. What is this? Battery issue?
It'll put itself into deep sleep after a while to preserve the battery.

Thought it was something like 7-10 days without use? But again, it could be sooner if you're doing high drain/low mileage trips.
 

· Registered
2019 Mk8 Fiesta ST-3 Mountune m260
Joined
·
161 Posts
Start/stop has never worked in my car as it's always driven in sport mode 😆

28mpg sounds about normal for me, also because it's always driven in sport mode 🤣
 

· Registered
Fiesta ST-3 Mk8.5
Joined
·
140 Posts
Here's my experience of those issues in the 4months I've had mine...

1) Interior lights have stopped working twice, but both times were after I'd been away for work and car had been sitting for a full week. On the next drive they came alright again.

2) I tend to find my stop/start won't always work in when it's really cold and I've got the heaters blasting. On the milder days it's pretty much solid.

3) I'm finding the mpg of my Mk8.5 slightly worse than my Mk8. Old car averaged 44mpg over 1 year and 13k miles. New one is averaging 40mpg over it's first 3k miles. One thing I did find with the Mk8 was that the mpg gradually improved through my ownership and is definitely better during the summer months (sometimes hitting 49mpg!). This is mostly on B road 30 mile each way commutes.

I have one more issue with mine when I leave it sitting and that's the back brakes get a bit noisey/grindy, but they come alright after a few miles again.
 

· Registered
Joined
·
173 Posts
Im not impressed with this 8.5 as much as my previous mk8. (Had mine since March 2022) My light's havent worked for ages, the MPG seems to be getting worse like you say. My mechanic just lowered mine and at the same time noticed how low on water it was, so put more in, and said he shouldn't have had to put so much in for a car that's only done 7k miles.....worrying!
According to the ford app its in DEEP SLEEP MODE...... load of c**p because i do the same amount of miles as i did in my mk8 and never ever had a problem. It's got it's first service booked for the 27th Feb, so i'm currently writing a list of things im not happy about... These mk8.5's are nothing but Friday afternoon builds.... totally fobbed off by Ford.
 

· Registered
Fiesta ST Edition
Joined
·
11 Posts
I have my mk8 edition for abour a year now. On the first month due to bad weather and not driving too ofter, my car went to deep sleep mode. Start/stop and auto unlock stopped working. I did the procedure with the blinking lights that resets the battery monitoring system and everything was fixed! Disabling secureAlerts also helps with the battery. No problems since then.
 

· Registered
Fiesta ST Edition
Joined
·
82 Posts
I‘ve been having the same issue with my stop start at the moment. Put it down to the cold weather, plugged it in to a ctek charger to top it up, worked the next day I drove it. Although a bit more hit n miss today. Perhaps you could try one out to see if there is a problem or not, as some models can tell if it is holding charge etc. It could save you paying out for a dealer to do a diagnostic and they end up not finding anything. Maybe every so often take it out on the motorway if it is only used for short journeys.
 

· Registered
2023 8.5 Mean Green hopefully
Joined
·
95 Posts
pretty sure that at low temps and maybe with lights, heater fan, heated rear screen and stuff putting a load on alternator/battery, the stop start is inoperative by design rather than having a fault.
 

· Registered
Joined
·
202 Posts
TCU Telematic Control Unit Module need to be updated with the newest software in Ford Workshop, so that's better for the battery. New Software will reduce battery drain in sleep mode. When software is up to date, charge the battery for some hours until its full to 100%
 

· Registered
Joined
·
108 Posts
I think I'm the only person happy with their 8.5 😅

I average around 32mpg, primarily due to my morning commute. Although 30 minutes each way it's on a large incline and there's always 6/7 minutes of first gear crawl traffic at 5mph. Had it up to around 47ish mpg during summer last year on some motorway journeys. MPG tends to be better if I use the speed limiter and my foot rather than cruise control.

Start stop works once the coolant has warmed up a bit and the car is warm enough to be happy turning itself off for a few seconds at lights, although I rarely use it, even putting the car into sport to avoid it in winter so it warms itself up properly.

Only had the deep sleep issue when the car was in for the window replacement, took them a few weeks and was checking occasionally to see if the car had moved on ford pass. Haven't had it since, not even in winter, although given how lacking the features are, I tend to not check it much anyway.

The car already has the fuel gauge, oil life and TPMS readouts, I don't need my phone for that.
 
1 - 19 of 19 Posts
Top