Please Help Diagnose This Problem

[McNugget365]

Hi,

I currently have a problem with my 2008 mk 2(possibly 2.5) focus 1.8 style (petrol). 55k miles

When I'm driving along, if I put the car in neutral and release the clutch to coast to a stop, once I get to a stop the engine starts chugging and dies unless I put the clutch back in. If I come to a stop in neutral with the clutch depressed the problem does not occur. (I can try and get a video of the rev guage if this helps?)

The same thing happened on a mk1 focus I drove briefly so im assuming its a common problem however I cant seem to find the problem on google.

I have narrowed it down to the following,

Idle Control Valve needs replaced- don't think its this as the car idles perfectly when stopped

MAF needs replaced

Throttle Body Problem

Speed sensor in gear box

Please let me know your thoughts as I don't know much about cars and don't want to get charged an arm and a leg going through every part if I can help it.

Also, on an unrelated note, does this model of focus have a timing chain or timing belt.

Thanks :)

[wase16ll]

not bing funny mate, but why are you putting car in neutral before you stop?

thats not a great habit

leaving in gear and dipping the clutch at last moment will do wonders for extending the life of your brakes as well as braking efficiency.

besides that..as im really not sure if that practice affects the running, bearing in mind that you have (i believe) a clutch, brake and throttle pedal position sensors amongst other things.

not that familier with that engine set up, so not sure how much cleaning can be done on the throttle body, but maybe worth cleaning around the throttle butterfly to start with..also have you any service history, as you'd be suprised how nice fresh oil can make a difference to minor faults such as this, along with the usual filter changes.

believe its a chain engine, but not 100% on that

[McNugget365]

Thanks, will have a look at your suggestions, ordering a new oil filter and air filter now to do a bit of maintenence on it

As for the bad habit, yeah its a bad habit, don't know why I do it, just always have, probably because I know I'll need to go into neutral at some stage so I get it out of the way as soon as I start braking, and I'm far too lazy to wait until the last minute before pressing the clutch

[artscot79]

Its likely youre habit causing the problems with the throttle sensor speed sensor etc registering a moving car yet the car not in gear the sensors dont know whats going on

[leesheffield]

Its likely youre habit causing the problems with the throttle sensor speed sensor etc registering a moving car yet the car not in gear the sensors dont know whats going on

I've had this same issue. I've come to the conclusion that it's what you have suggested. Have got out of the habit now as I Kinda scared myself with it the other day. Was going round a corner and decided to change gear at the wrong time. Car decided to cut out. I'd like to say outright I don't normally do it and plan ahead for corners but this day I was tired first thing in the morning and not fully paying attention. Bad I know dont judge lol. Not very nice with no power trying to turn a corner. Managed to start car again and roads were clear. I've read elsewhere of this happening because of sensors not knowing what is going on. Deffo only dipping clutch at last second now!!

Lee

[artscot79]

try it and see how you go if the problems solved cheap fix if not then ide suggest the vss sensor or a loose wire somewhere