Question about 1999 Ford Mondeo

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Car engine cold but thermostat goes onto red!

We replaced the switcher unit (I think that's what you call it) and now the car has immediately gone onto the red even though the engine is cold! Any ideas please because this is ridiculous and becoming a real pain in the you know what!

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  • 17 Answers

Some cars have more than one sending unit for the temperature. You probably bought the wrong one.

Posted on Jun 09, 2014


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Posted on Jan 02, 2017

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SOURCE: 200 Ford Focus 1.6, temperature gauge at full, even on ignition

is it your impeller, got a ford st24 and had the same problem,could only drive a short way before it got too hot again but the felt cold.

Posted on Dec 15, 2008

  • 2 Answers

SOURCE: fiesta mk 5 heater problem

the heater control valve on the fiesta mk5 are common to fail ...ebay £15 find two thin hoses going from the engine to the scuttle panel and youll see it .easy changeover

Posted on Dec 30, 2008

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SOURCE: location of thermostat

Did you run the engine with rad cap off & heater (not defrost) on while topping up the coolant. If not, do it & let it run that way until your rad fan comes on & off about 3 times, then top rad up to a inch or 2 from top, and put cap back on, & check level in return bottle.

Posted on Jan 16, 2009

  • 4 Answers

SOURCE: 1996 ford tarus location of coolant temperatue sensor?

I doubt if it is the temperature sensor if the gauge is working. Check to see if the fans are coming on when the engine is hot. The fans have two speeds and should come on in low speed and change to high speed as temperature gets hotter or when air conditioner is turned on. If they are working correctly. I would guess the radiator is partially plugged up between the air conditioner condensor and the radiator. These cars are bad about getting dirt, lint, and what ever trapped in this area.

Posted on Mar 01, 2009

  • 11 Answers

SOURCE: temp guage keeps pegging out to high side.....

listen u need to replace the water pump! if u have under drive pullys u need a high performance water pump wich a regular or high performance which u want one that is still pully driven dont get the all elictrial unless ur going a 1/4 mile at a time. go to also burp ur system had the same problem not now

Posted on Apr 03, 2009

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The temperature gauge goes to the High and basically makes like a dinging sound, then it goes back down almost immediately. The car has not overheated but does make a gurgling sound when we shut the car...

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I had the same problem mine was the waterpump.
Do not let the engine go into the red. If you do you are in danger of warping the head and then bigger problems

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