Ford Cmax 2008 Glow Plug Problem

[seansillman]

hi I hope somebody can help I have a 2008 cmax

recently in the cold frosty mornings my car was taking ages to turn over and start so I called my local mobile mechanic to change the glow plugs

so a couple of days later he came to check them and change any that were blown upon checking them he found all for of them were blown he checked the voltage to them and it was about 14v (I think) the voltage went down slightly to around 10v after a minute or so with the engine running however they did not turn off he has said that they should turn off about 20seconds after the car is started however this is not the case he has checked the relays in the fuse box and they seem to be functioning correctly there is suppose to be a relay on the passenger side beneath the air box on the chaise rail under the head light however he can not locate this

can any body please advise on what the fault may be

[supercmaxer]

The relay for the glow plug is under the n/s head lamp not under the air box.

Do you know of you had any fault codes?

It might not be the glow plugs but the starter as I've read else where. Check voltage across the battery when car is off and then on, you should get 12.5v when of and about 14 plus v when the car is running.

[seansillman]

thanks for this I will get this checked out tomorrow there is also no fault codes coming up on the reader

[jeebowhite]

Im sure that for emission control they stay on for longer than 20 seconds after the car is started, they stay on until the car is up to running temperature....

[simcor]

Yep glow plugs are used for emissions amongst other things these days and will stay on once the engine is started, they are also used for other things like DPF regeneration etc. Glow plugs are not needed unless the weather is extremely cold on common rail diesel engines generally colder temps than we are used to here. A common rail diesel should start on the button with the key turned straight away without even waiting for the glow plug light.

I bet the user manual states to turn the key straight away and no mention of waiting for the glow plug light.

[Sam1ukuk]

Hi we have trouble with our 1.6 2008 Ford C-Max! Had computer plugged in and it says its the glow plugs. Keeps going into limp mode. I'm trying to find the glow plug relay but cannot find it anywhere. Can anyone help me please on where to find it.

[TomsFocus]

16 minutes ago, Sam1ukuk said:

Hi we have trouble with our 1.6 2008 Ford C-Max! Had computer plugged in and it says its the glow plugs. Keeps going into limp mode. I'm trying to find the glow plug relay but cannot find it anywhere. Can anyone help me please on where to find it.

The relay is in the fusebox under the bonnet, there's a diagram inside the lid.  The glowplug relay has the coil symbol as you'd see on the dash.  

It usually is the plugs themselves at fault on the 1.6 TDCi though.  The PCM uses the resistance feedback to switch them off, when one burns out the reading gets thrown out of spec so they stay on forever until they all burn out, brilliant piece of design!