Got A Few Problems, Starting, Misfiring

[RobA]

Hi guys,

Newbie here with a few problems with my 2007 1.6 115 petrol focus.

Had some rough running last winter and had the EML come on, went to my local mechanic, plugged it in and it was the coil pack failing, so had that replaced and it seemed to be fine for a while.

Then at the end of winter the coolant seemed to take a lot longer to heat up and whilst it was warming up the temperature gauge would go up and down until it got up to normal running temperature, as if it was letting cold water through and "cooling" the temperature sensor. The MPG was also very poor, (23, vs the 38 I'd had for the last two years).

Went back to my garage and he recommend replacing the temp sensor as that sounded like the cause of the problem.

I replaced that but by the time I'd done it, it was summer and I didn't have the coolant temp problem, now winter is upon us its risen its head again along with the poor mpg.

I have also got a starting problem which to me sounds like the ring on the fly wheel has worn the teeth down which means the starter isn't engaging and just "tinging" on the worn teeth.

If I push the car in gear and make the engine turn over manually it will then start fine.

Or is it the battery starting to fail which isn't giving the starter enough juice to put the cog out far enough.

I think it's the original battery as I've owned it since December 2011, haven't replaced it and it has got ford stickers all over it.

Is my diagnosis correct, I believe its a gearbox out to replace the toothed ring?

Last one, which I think is related to my first problem, when on the motorway using cruise control it will judder every so often as if it's got a slight misfire, reading on the web, if the ht leads are failing it can take to coil pack out as well so should I replace them?

Sorry for so many questions for my first post, but I've finally decided I need to get it sorted and this seems to be the place to get some advice.

[mjt]

I don't think the starter isn't putting the cog out far enough. It's been a long time since starters used inertia to engage the pinion. Nowadays they're mechanically engaged by the solenoid and the motor does not receive any power until after the pinion is almost fully engaged. Using this system avoids the kind of wear to the pinion and ring gear that used to occur with the old system so I'd say it's very unusual to get that sort of problem now. I guess the only way to find out is take the starter off and take a look.

I think it's unlikely to be a low battery problem as in that case the most likely scenario is that the starter would engage but not turn the engine or turn it very slowly.

[artscot79]

The 115 has an electronic secondary thermostat the coolant temp will go up and down before stabilizing in winter its not a fault second to check the battery do the dash test engine running you want 14.4v any garage will test the battery for free.the coil pack is a pain if you have a fault you should change the plugs the coil and leads as anyone of those can cause the coil pack issue to start with also a genuine coil pack is required tge cheap ones dont last much past the 12mth gaurantee.

The problem you have is you need fault codes and the car needs checked on the live data to pin point the fault the cat can cause a misfire plugs leads coil pack plug gaps amoung other things

[RobA]

Cheers guys, I've got a Haynes manual so will have a go at removing the starter and checking the ring.

The coil pack I fitted is a genuine Ford item. I'll give Ford a ring for a price on spark plugs and HT leads on Monday, has anyone got a rough price to expect so I know if they're trying to charge me to much.

The battery voltage is 14.2 volts when running so I'm pretty sure it's fine, I've got a charger to keep it topped up as it doesn't get used much now.

[artscot79]

The plugs are Bosch iridiums with a ford stamp and genuine leads are £60 ish these are also Bosch as is the coil pack i cant help with the starter but the misfire ide look at the simple things first check the air filter there should also be a small square one that catches oil vapour from the crank case and ensure that the hose is connected to the airbox secondly check theres no water in the spark plug wells then check the plug gaps new plugs are pregapped at 1.3mm they should be 1.0mm though this can cause rough idling and running third at the front of the engine youll see a hose that connects to a pcv valve take that out it just pulls out and clean in white spirits with no fault codes thats as much as you can do.after that you need live data it could be a wiring issue to the coil pack or the ht leads an o2 sensor and you can soend 100s trying to cure it.

There is another issue that can cause all the problems which is the ti vct solenoid is failing and not retarding or advancing the cam and also the ti vct when you switch it off you should hear outside the car a few clicks this is the system reverting to its starting position and should happen if it isnt then the car will struggle to start again easy to check first