northern_nubie

In the Lane Keeping System I've now changed the mode to Alert (other two options are Aid, and Alert & Aid). It was set to the Alert & Aid. I set the Alert Intensity to the lowest setting. It was on the medium setting. When I changed the setting it didn't demonstrate the vibration intensity, so I've no idea how less intense it will be. When you change the intensity in settings, with engine turned on, does the steering wheel vibrate in your Focus? I'm in two minds about whether to take it into a dealer. It's booked in for Wednesday. I never use Lane Keeping, but may have turned it on accidentally as I started to overtake. In the stress of what happened I'm fairly certain that it was more than just steering wheel vibration (though it might just have been that). Strangely, even when I'd pulled in a 100 yards further on and was stationary, the vibration was still taking place - until I'd turned off the car. Is the vibration supposed to turn itself off after a while, or after you've taken action to get back in lane? And, as I said above, just before turning off the car, I noticed the display behind the steering wheel said something about Auto-brake having operated (or similar words). But there'd been no audible warning.

I've got my Focus booked in with a dealer, next week, so they can plug it in and perhaps see what happened. But I was browsing the user guide today and came across Lane-keep Assist. I've never used it, but I see it's very easy to turn on, on the end of the indicator stalk. I'm wondering if at least part of horrible thing I experienced was me inadvertently turning it on. I usually indicate when pulling out to overtake on a dual carriageway, which would disable lane-keep assist if I'd accidentally just put it on. But maybe I didn't indicate. Maybe lane-keep assist kicked in. The warning, I read, is vibration, exactly what I experienced - but in my case really bad vibration. But also Auto-brake kicked in too, I saw it on the dashboard display when I pulled in. When the technicians plug into my car, will they be able to see all events - such as whether lane-keep assist was used on that day, at that time, do you think? And auto-brake too?

Since posting, I've concluded it may be far more than a problem with the pre-collision assist coming on when it shouldn't. Just replied to Alex below, and added a bit more info about what happened.

Thanks for the reply, Alex. I've booked it into the dealer (week after next) so they can see if an event has been logged by the system. I hope so, because since posting this yesterday, I've concluded it was far more than just auto-braking. Today, thinking back to what happened, I'm pretty certain the car was accelerating itself. Hard to explain. It was a very odd, alarming and frankly dangerous incident. I only remembered today because to be honest I was a bit in shock yesterday and tired. And the loud noise from the engine, and possible vibration - none of it makes sense to me in the context of the pre-collision assist system. If it had just starting heavily braking, then fine. But it all sorts was going on.

Of course, I could contact Ford UK, wait over a month for the tech team to get back to the front line staff (as has happened several times to me in the recent past), only to be told very little of any use. They usually say go to the dealer. But if the dealer doesn't have very good information, there is no one to ask.

Today, I had an alarming experience, out of the blue. Just left a roundabout and was on a dual carriageway. Going about 40mph, in 4th gear. Went to overtake a car, and suddenly it was like a nightmare. Horrible loud, constant noise from engine, it seemed, and couldn't accelerate. The noise was terrible. I thought this is a major problem, an emergency and I needed to stop. For a second I wondered if I had a flat tyre. Luckily there was a bus stop lay-by a hundred yards ahead. Pulled into it, still with the same problem and noise even when stationary (it was like the car had suddenly turned into a tractor, the noise was so bad). Turned off the engine. Then restarted the car. All was fine. The noise, and maybe what felt like vibration, was the worst. Before turning off the car, I happened to notice a warning 'Auto-brake assist something something'. It seems from the user guide that auto-brake can put the brakes on if it senses a possible collision (part of the pre-collision assist system). I rang the large Ford dealer where I bought the car, then the local Ford dealer. I wanted to know if the noise is something which should happen during auto-braking. But because it's rare for it to happen to anyone, they had not experienced it and couldn't tell me. It feels like the car should be checked for damage, but what checks can they do? You'd think Ford dealers would have access to a technical manual of sorts, something to let them know what happens precisely during auto-braking. It's made me slightly wary of the car, to be honest.

I showed my local Ford dealer this, and had the usual less than reassuring response I've had in the past from Ford dealers, when I asked them about other issues on my previous Focus. They often don't know answers to things you'd think they'd know straightaway. The senior tech I showed this to, first of all said it looks like it could be caused by a leak from the coolant reservoir. When I said I don't think it is, he said, oh no that would be orange in colour I suppose. Then he said it's corrosion and "is normal" (seemingly Ford's stock answer to so many questions, even when things aren't normal). He didn't explain. So I said, if it's normal (which of course it may be) what's the cause? He said aluminium corrodes. Why he didn't say that at the beginning, God knows. Nothing about dendritic growth and filiform. As I say, I've had repeated instances this sort of response. It's one of the key things I've found frustrating about dealers.

Before posting, I rubbed a very small part of it and it wipes off a bit onto your finger, but most remains on the metal. Unofix's reply below yours was very enlightening.

Thanks so much for this. I'm reassured now. I also noticed it on a relation's 2008 A3, covering most of the aluminium parts, but perhaps not quite as thick. But maybe it just looks a little thicker/worse at the moment on mine because it contrasts against the surfaces which don't yet have the growth.

I wondered if anyone else has experienced this corrosion on their vehicle? And if so how old is your vehicle? Going to get it checked at a dealer next week, but thought someone else may have experienced something similar. Not the sort of thing I'd expect on a car a year after its manufacture, but I could be wrong of course.

Thanks. That makes sense, of course.

1. Just spotted what looks like corrosion on a bracket near the engine. Also spots of it nearby on the metal below the red circle on the first photo below. Bought the car 6 months ago, new. It was made, I believe, in March or May 2022. It's a hefty, thick part, so it's not going to cause a problem any time soon. But why is it there, and so soon? I don't live near the sea, I regularly clean the car, including underneath, and everything else is fine. It rubs off on your fingers, but not entirely off the bracket. Anyone else experienced this? 2. (Minor point) When using cruise control, the speedo needle matches the digital readout. But when not in cruise control (most of the time for me) the digital readout often displays a speed which is one and often two mph higher than the needle. For example, the readout says 32 or 33mph and the needle is barely above 30mph. Didn't notice it on my previous Focus, a Mk4. 3. (Very minor point) My PDF warranty document says "before any Warranty work is carried out to Your Vehicle, produce Your Ford Service History Log duly stamped..." Logs no longer exist in paper form. I even tried to buy one, after buying the car. And the document says "All parts which are replaced under this Warranty shall belong to Us." Puzzling.

Update: the shield is just a lightweight plastic part which can be popped up from the stud underneath it, which was originally one of the studs for the cover on the Mk4. Or early Mk4s, as Tom pointed out above. Once popped up, it's still attached to the two cables, of course. I don't really want to trim the underside of the cover, and even if I did, the cover would only be fixed in three places. Not ideal. As Alex said above, it's likely the cover was deemed helpful in securing the cables, but without the cover, some form of stability was thought necessary, hence the shield and tie-wraps. The cables are stiff and held firmly in nearby slots, without the need for the tie-wraps, imo. Here's my fix, which I've decided on and will do tomorrow: pop up the shield. Carefully cut the tie-wrap on the right (which, if need be, could later be neatly super-glued back together. It doesn't look possible to replace the tie-wrap due to the way it's attached to its base, though it may be possible). The top tie-wrap does not need to be cut. The shield can be swiveled clockwise and down a bit, out of the way, revealing the stud. The top tie-wrap spins freely at its base. The moved shield will be low enough not to hamper fitting the cover and will not be near other components. It can be secured to the top cable with a tie-wrap. Or I may cut both tie-wraps and remove the shield. (I tried to pull the tie-wraps from the slots they're inserted into in the shield housing, but it was impossible, even with a lot of force and needle-nose pliers.) (I've written this short essay for Stephen, as I know he appreciates lengthy comments :) I appreciate all your comments and help in recent months.)

Good analogy, in a way. But I intend to keep the car for as long as it will last, and I just prefer to avoid a build up of dust which does build up and isn't that easy to brush off after a number of years. Also looks better, even though the cover covers far less than other makes and models of car.

It doesn't press down, though I can see why it might look as if it does. Tomorrow I'm going to see if the cap will flip up and off, then I will perhaps see if the whole thing comes off. Didn't occur to me to try the day I posted, and it's been pretty wet since. The cover I have would fit if the shield thing, as they call it, wasn't there. On a Ford technical drawing I have, showing the studs, cover and shield arrangement, the shield seems to be optional. As another reply said here, the tie-wrap especially for the top cable would be because without the indent under the cover, there's nothing to secure it.