Ford focus 1.6 - cooling system hoses/ high speed temperature

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Sun 21 Feb 2010 15:08
Ford focus 1.6 - cooling system hoses/ high speed temperature - harrogate big vern
I have had a sudden increse in temp at high speed for some time, although fine in every other respect. It usually falls back as quick as it has come.

Trying to decide what to do and unsure if it could be an air lock or a blocked radiator.

Can anyone advise what each hose connected to expansion tank or radiator are, or provide a diagram.

Also any idea how much i should pay for a flush and replacement of the coolant.

Thanks
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Sun 21 Feb 2010 15:30
Ford focus 1.6 - cooling system hoses/ high speed temperature - L'escargot
If you let the car idle, with the heater set to cold, does the radiator fan eventually switch on? It may take some time for this to happen, with the low ambient temperatures we have at present.
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Sun 21 Feb 2010 15:39
Ford focus 1.6 - cooling system hoses/ high speed temperature - harrogate big vern
Yes it does.

The only sympton is the one described. Worth pointing out that it rises from the mid point to red in an instant.

I am going to try feeling the radiator, (not easy with the fan in place) as over the last couple of days when I have tried this it seems to be quite cold. Will get it fully warmed up and see whether it remains so.
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Sun 21 Feb 2010 17:15
Ford focus 1.6 - cooling system hoses/ high speed temperature - jc2
Sounds like a radiator that is past it's best.
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Sun 21 Feb 2010 17:39
Ford focus 1.6 - cooling system hoses/ high speed temperature - mikej
My old Focus suffered similar symptoms (overheating under load) and changing the coolant and the thermostat fixed the problem for me.

If you're getting the coolant changed, then it might be a good idea to change the thermostat at the same time anyway - it's not an expensive part (£12-odd IIRC) and was easy to change... on my 1.8 at least.
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Sun 21 Feb 2010 18:33
Ford focus 1.6 - cooling system hoses/ high speed temperature - harrogate big vern
Thanks for suggestions.

The radiator and thermostat are looking most likely. If it was an airlock would I be right in assuming it wouldn't necessarily only do it at speed?

Does anyone know whether the alternator has to come off to change the thermostat? The haynes manual is a bit vague on this.

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Sun 21 Feb 2010 20:40
Ford focus 1.6 - cooling system hoses/ high speed temperature - mikej
"Does anyone know whether the alternator has to come off to change the thermostat? The haynes manual is a bit vague on this."

I never found the Haynes Manual to be vague for any of the jobs I tackled on my old Focus - it should state clearly if you need to and refer you to that chapter.

The thermostat housing on my 1.8 was easily accessible from the front of the car without needing to remove anything major IIRC, but the 1.6 engine bay is set up differently to the 1.8.
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Sun 21 Feb 2010 19:07
Ford focus 1.6 - cooling system hoses/ high speed temperature - WellKnownSid
Worth pointing out that it rises from the mid point to red in an instant.


My FIAT does this from time to time. A sharp thump on the dashboard in the right place brings the needle back to normality just as quickly as it went into H.

It might be worth ruling that out before you take the engine apart...
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