Engine warning light

[swakelin91]

My car's engine warning light came on the other day, and I was looking for some advice as to what could be the problem. I haven't driven the car since, and won't be able to take it to a garage for another week until payday.

The car at hand is a Ford Fiesta Zetec S MK6. Recently it has had some overheating problems, caused by a leak somewhere in the coolant system, however I'm not sure whether that is related as I have been topping up the water levels to ensure it doesn't overheat again.

Recently when I start the car, the engine judders, and shakes sometimes cutting out, sometimes starting fine. Then about 20 seconds later the car seems fine, and driveable, there has been no difference in the performance of the car either. Then last Friday the engine management light came on as I started the car, and like I say I have not driven it since then, just in case.

I'm hoping it is just a sensor, or something similar, however I realise the issue could be something more substantial and I don't really have the knowledge to pick out the fault, or rectify the fault if possible, so was hoping for some guidance.

Thanks in advance.

[P I Staker]

Go to a garage, most of them specialise in fixing cars.

A quick diagnostic check with a computer will give the mechanic a fault code and point him pretty close to the problem.

[morgrp]

I'd be considering checking the head gasket - the gasket can weep and water can leak through into the cylinders causing rough running whilst first starting the car - May also explain the overheating and water loss

[HustleRussell]

The first step is to fix that coolant leak. A coolant leak can be a big issue for a car, and can cause a lot of further problems. After that, the car needs plugging in to an On Board Diagnistics computer to interrogate the ECU to determine the instagator of the warning light, so that it can be fixed properly and permanently with zero cash/time wasted in unsuccessful attempts at random trial and error diagnostic attempts.

[swakelin91]

Head gasket is ultimately what I feared, however I would have thought there would some sort of loss of performance if that was the case? I am probably wrong though.

Diagnostic check is obviously the best bet after pay day and hope for the best.

[morgrp]

swakelin91 said:

Head gasket is ultimately what I feared, however I would have thought there would some sort of loss of performance if that was the case? I am probably wrong though.

Diagnostic check is obviously the best bet after pay day and hope for the best.

Not necessarily - I've had cars in the past with weeping HGs and driven them for months and months just keeping an eye on the coolant level and they've performed fine.

Other tell tale signs are, Blackening/sooty deposits in the coolant exaplsion tank, Discoloured coolant, small fluctuations in temp gauge whilst drving (namely the temp will creep up under load and drop when you back off) Also the heater becomes weak with the pressurisation of cooling system. A simple pressurisation test should give a good indication of HG leak

[Mound Dawg]

morgrp said:

Not necessarily - I've had cars in the past with weeping HGs and driven them for months and months just keeping an eye on the coolant level and they've performed fine.

Other tell tale signs are, Blackening/sooty deposits in the coolant exaplsion tank, Discoloured coolant, small fluctuations in temp gauge whilst drving (namely the temp will creep up under load and drop when you back off) Also the heater becomes weak with the pressurisation of cooling system. A simple pressurisation test should give a good indication of HG leak

You've just described my last head gasket failure perfectly.

[Garvin]

Sound like a classic electronic accelerator control (EAC) problem. Usually a dodgy connection to the main ECU - common problem on Fiestas.

[swakelin91]

Turns out the only problem was the spark plugs so a nice cheap fix.

[amusingduck]

Check the coolant expansion tank.

Mine had a tiny crack underneath, which I didn't spot until it had lost lots of coolant and blown the headgasket.