Hi

I have an 05 1.4 fiesta diesel that has developed a problem in that it will not start with warnings on the dash for overheating(engine is cold) and water in the diesel.

I had a similar problem over a year ago when changing the fuel filter, putting the the old sensor back in the new filter cured it, which left me thinking it was the sensor.  It has now reoccurred again, this time a new filter with the built in sensor cured it for about 20 seconds, but it has come back.  When it occurred this time I had been checking the fuses one at a time and changed the one for the ABS pump which has worked since.

Any ideas will be gratefully recieved.

Nigel

You have water in your Diesel. Why would you think there isn't? That is what the display indicates.  If the new filter gets wet, it blocks the flow so drain  the tank into clear containers and take a look. The overheating with a cold engine is probably due to a shorted sensor or a frayed sensor wire earthing out. Maybe you have swapped the connections between the two sensors but I would fix the water in fuel issue first. Fitting a new filter gets a start until the amount of water builds up to clog it  which explains your symptoms.

anon- Thank you for your comment. it is appreciated. A few areas that do not fit in with water in the fuel being the root cause.

1) Before the issue re-occurred I had just driven the car and had no trouble.

2) I had not fuelled the car for over 3 weeks.

3) Two totally unrelated(physical) problem warnings occurred at the same time.

4) The same issue(s) have occurred previously when it was solved temporarily(over a year) by replacing the filter sensor

5) The "overheating" disappeared by changing the filter, if only temporarily.

6) The initial filter was partially drained to remove any possible water.

7) We are in the driest period for many years should the tank have an unseen hole allowing moisture in.

😎 I did not mention as I thought it might complicate the issue that - I had a auto elec(that cannot come out again for a while) to look at the problem and he found that there was a communication problem that disappeared as he looked at it.  He got it going and it ran for for perhaps 20 seconds only for the problem to reoccur immediately a few days later seconds after I used the car for the first time after the "fix".

9) I have since my initial posting read of similar problem with corrosion somewhere to the rear of the fuse board being the cause. I am however, more than a little afraid of pulling it all apart and getting it all back together again!

I now think the problem now perhaps lies somewhere as mentioned in 8 and 9 especially given two totally unrelated physical issues being indicated.  How I get there.........?

 

 

You decided not to give us the full facts. How did you possibly think that was going to be helpful?

The only sensible possibility is that you didn't cure the problem by changing the sensor but you disturbed the frayed, broken or shorted wiring and got temporarily lucky. Get an auto electrician who knows what he is doing to analyse the fault properly. If he cannot come out again for a while, get another one. 

9. Charlie on the internet says it is this, so it must be. Um, no. It is far more likely not to be the case and you stand a very good chance of breaking something that wasn't broken. Guesswork  is the worst of diagnostic tools in the wrong hands.

If you cannot find any break, short or dirty connection in the wiring, and the CANBUS isn't running the PCM

(the assumed communication failure, based on what you have now told us,)

then you're out of your depth and will need the services of a professional.