Okay cheers,

maybe I can go into my local garage and ask them nicely. Is it worth getting the air con sorted as a side note?

11 minutes ago, bockercharlie said:

Okay cheers,

maybe I can go into my local garage and ask them nicely. Is it worth getting the air con sorted as a side note?

Your local garage won't have Forscan.  Their generic code reader is unlikely to find the specific Ford codes we're after.  It's a free programme for a laptop, or costs a few quid for a phone app.  Then about £20 or so for the lead/dongle.  Easily pays for itself compared to a main dealer visit, and ideal if you have friends or relatives with Fords as well.

Air con diagnosis is up to you...personally, I can't be without it in summer, but I hate the hot weather lol!  Though it can get expensive if you find multiple faults.

Ah okay. I’ll look into getting that then! So if I get this forescan software and buy the lead then it’ll give me a fault code which will help with the repair?

 

out of interest, say I fixed the fan last week when I changed the coolant sensor, how would I know? I’ve tried to get the fan to come on automatically by driving on the motorway for half an hour then coming to a stop and leaving it running, but nothing.

1 minute ago, bockercharlie said:

Ah okay. I’ll look into getting that then! So if I get this forescan software and buy the lead then it’ll give me a fault code which will help with the repair?

 

out of interest, say I fixed the fan last week when I changed the coolant sensor, how would I know? I’ve tried to get the fan to come on automatically by driving on the motorway for half an hour then coming to a stop and leaving it running, but nothing.

It should give you a code if it's an electrical fault but I can't guarantee there will be one!  If there are no useful codes then we have to assume that it's a physical/mechanical issue.  But that requires more expensive, time consuming, trial & error, replacing parts that may not be faulty.

You'd need a live coolant temp reading to check if the engine has got warm enough for the fan to come on...fortunately, Forscan has a live data function too!    From memory, I think the stat opens at 82c, the low speed fan starts at 98c and the high speed fan starts at 105c on those.

On 4/2/2022 at 11:01 AM, TomsFocus said:

It should give you a code if it's an electrical fault but I can't guarantee there will be one!  If there are no useful codes then we have to assume that it's a physical/mechanical issue.  But that requires more expensive, time consuming, trial & error, replacing parts that may not be faulty.

You'd need a live coolant temp reading to check if the engine has got warm enough for the fan to come on...fortunately, Forscan has a live data function too!    From memory, I think the stat opens at 82c, the low speed fan starts at 98c and the high speed fan starts at 105c on those.

More interesting bits..so I've been playing with this morning. I started it up for 10 mins and nothing happened. Then I removed the coolant temperature sensor clip from the sensor and hey presto...the fan comes on..see video..

 

31 minutes ago, bockercharlie said:

More interesting bits..so I've been playing with this morning. I started it up for 10 mins and nothing happened. Then I removed the coolant temperature sensor clip from the sensor and hey presto...the fan comes on..see video..

Yes, that's the failsafe mode.  But only proves what the AC test already proved, that the PCM is communicating with the fan.

10 minutes ago, TomsFocus said:

Yes, that's the failsafe mode.  But only proves what the AC test already proved, that the PCM is communicating with the fan.

Ah okay so not necessarily indicating that the coolant temp sensor is busted? Because I’ve just replaced that last week lol 

1 minute ago, bockercharlie said:

Ah okay so not necessarily indicating that the coolant temp sensor is busted? Because I’ve just replaced that last week lol 

Not at all, the fan comes on as default when the sensor is unplugged.

Tom, Does the Fiesta have the same facilty to get a live reading by putting the dash into test mode ?

The Haynes Fusion manual describes a test sequence and lists the indications, including temperature, but I have never tried it either on our Fusion or Fiesta.

10 hours ago, Paulkp said:

Tom, Does the Fiesta have the same facilty to get a live reading by putting the dash into test mode ?

The Haynes Fusion manual describes a test sequence and lists the indications, including temperature, but I have never tried it either on our Fusion or Fiesta.

It does, but I haven't tried it on the Mk6 either (or at least can't remember if I have!).  On the Mk2 Focus, it gives a very strange reading, roughly 40c above the 'real' temp, so I didn't want to suggest it here in case it's the same.  This YouTube video appears to show both external and engine temp as roughly the same (18/19c)...so assuming it was taken with a cold engine, that would appear to be correct and worth a try.

 

13 hours ago, Paulkp said:

Tom, Does the Fiesta have the same facilty to get a live reading by putting the dash into test mode ?

The Haynes Fusion manual describes a test sequence and lists the indications, including temperature, but I have never tried it either on our Fusion or Fiesta.

I tried this yesterday. The engine got up to 102 Celsius with no fan, so i shut it off. Any ideas?

29 minutes ago, bockercharlie said:

I tried this yesterday. The engine got up to 102 Celsius with no fan, so i shut it off. Any ideas?

Have you tried Forscan for any codes yet?  I would've let it get a little higher personally, just to see if the high speed fan comes on.  If it gets up to about 110c and still no fan, put the interior heating on full and the blowers on full speed to draw some of the heat out.  Switching off with high engine temps isn't a great idea as it stops the coolant circulating and causes hot spots in the system which could warp components.

I think you've lost the low fan speed function.  But without a resistor on your fan cowling, I'm not quite sure how that's managed on your model.  I'm trying to remember if I've seen a resistor located elsewhere on these.

Edit - Hmm, just checked 7zap and it appears that some of these only had a single speed fan, so no resistor required.  Unfortunately, I don't know what temp the single speed fan should cut in...I wonder if someone with access to Autodata or similar may be able to check for us?

25 minutes ago, TomsFocus said:

Have you tried Forscan for any codes yet?  I would've let it get a little higher personally, just to see if the high speed fan comes on.  If it gets up to about 110c and still no fan, put the interior heating on full and the blowers on full speed to draw some of the heat out.  Switching off with high engine temps isn't a great idea as it stops the coolant circulating and causes hot spots in the system which could warp components.

I think you've lost the low fan speed function.  But without a resistor on your fan cowling, I'm not quite sure how that's managed on your model.  I'm trying to remember if I've seen a resistor located elsewhere on these.

Edit - Hmm, just checked 7zap and it appears that some of these only had a single speed fan, so no resistor required.  Unfortunately, I don't know what temp the single speed fan should cut in...I wonder if someone with access to Autodata or similar may be able to check for us?

I'm still trying the Forscan business..the stumbling block at the moment is I have a MacBook and I think the software only works on windows. The adapters that I can see are also quite expensive! 

 

I will try that then, 110 degrees and do the blowers! 

 

Thank you all for all the help, really appreciated. Only bought this thing to save money during covid so really keen to fix myself where possible.

 

12 minutes ago, bockercharlie said:

I'm still trying the Forscan business..the stumbling block at the moment is I have a MacBook and I think the software only works on windows. The adapters that I can see are also quite expensive! 

 

I will try that then, 110 degrees and do the blowers! 

 

Thank you all for all the help, really appreciated. Only bought this thing to save money during covid so really keen to fix myself where possible.

 

Ah, I don't know anything about MacBooks.  I take it you have an iPhone rather than Android as well?  

I'd hold off on the 110c for now until we can find out what temp the single speed fan should cut in.  I'd expect it to be lower than the high speed on a twin-speed fan. 

Not sure if that info is available on ETIS @iantt  ?

Okay will do cheers!

Quick update for all interested...I think I might have solved it..

 

I did a coolant flush today and as a precaution, replaced the coolant expansion tank cap. Turns out the old one wasn't in the best shape (only got replaced 12 months prior!). Anyway, filled up with coolant and took it for a blast and left it running for 15 mins.

 

Engine got up to about 105°c (verified by the 'secret menu'), before the fan came on! 😄

 

So my theory is, failed expansion tank cap probably caused the overheat in the first place (after 2 hours of motorway driving then a sudden traffic jam), since the system wasn't under pressure (liquids under pressure boil at higher temperatures, correct?). 

So the coolant boiled and ***** out everywhere at a lower temperature than normal, which wasn't high enough to trigger the radiator fan.

Thoughts welcome!

1 hour ago, bockercharlie said:

Thoughts welcome!

I'd say you're spot on with that diagnosis!  Hopefully it's all sorted now.

 

15 hours ago, TomsFocus said:

I'd say you're spot on with that diagnosis!  Hopefully it's all sorted now.

 

All that due to an expansion tank cap eh. Anyway thanks for all the help, really really useful! thanks for dumbing it down for me too. I'm loving learning more bits about the car.

thank you interesting topic, but I think it is better to contact the service station

 

hi, maybe you better go to the service station and they will repair your radiator. By the way, the guys from the service station advised me a very interesting thing, for example, Blue Devil Radiator Flush Review can be ordered at https://casperoilchange.com/blue-devil-radiator-flush-review/. I use it according to the season, I don't even check the water in winter, it doesn't even freeze with such a change

Could be a connection/corrosion at the fan unit end, had the connector replaced £60 parts and labour