I'm having an issue with overcooling on my 2.2D X-Type. Many threads on here point to the oil thermostat being the issue.


My question is - should the thermostat be open when its out the car, cold and in my hand?


Reason being, I expect not to be able to blow through it and it be closed (until its in the car and to the right temperature and it opens to allow flow), however I am able to blow through it if its cold and in my hand and when I put it in boiling water for a few mins and take it out I still can blow through it - surely there should be a difference if its cold v's hot position - otherwise what is the function of it ??


It really annoying that it take ages to warm up, never really goes above 1/4 mark and if I go down hill the engine goes back to cold.


I travel 30 mils to work on M6, warm air through the heaters as normal, if I boot it then I might get it up to half way 9normal mark) but cools down as soon as I stop booting it !!


Cheers


Andy

 

andy, I am assuming you are talking about the engine coolant thermostat, not an oil thermostat (not aware of one on the cars, but then, I don't deal a lot with the diesel engines either).

Based on being an engine coolant thermostat, the thermostat will be closed at a low temperature with a small amount of coolant being allowed to flow through (small hole drilled in the disk). Then as the motor gets warmer, it will open up to allow flow.

If you need me to go into more detail, let me know.

 

HI


There are 2 thermostats on this car. One being the coolant (normal water 'Main Stat' and one being the oil coolant thermostat (Jag Part number JD61162)


It sit on the side of the water pump.


Should it be 'closed completly' when cold ??

 

andy: Here's a simple way to test the coolant thermostat, adapted from ASE Certification Training HQ*|*The Original and #1 Website for ASE Certification Training:

Manually open the thermostat and insert a 0.015 in. (0.4 mm) feeler gauge. Suspend the thermostat from the feeler gauge in a pot of water and heat until the thermostat opens to release and fall from the feeler gauge. Use a thermometer to measure this opening temperature, which should be within 5°F (3°C) of the temperature stamped on the thermostat. The thermostat should fully open at ~20°F (~11°C) above the opening temperature.

 

Hi - I do not have a feeler gauges and may not be able to complete this with this type of thermostat.


I will try to upload a pic

 

Oil Stat

 

Andy: I'm not familiar with the 2 diesel thermostats, but the concept is the same. In lieu of a feeler gauge, pinch a piece of string in the closed thermostat, suspend the thermostat by the string in water that you heat up, and measure the temperature that the thermostat opens, releases the string and drops to the bottom of the pot.

 

On x-type, there is a small cooling system that cools the oil coming from turbo. It is connected to main radiator with a small thermostat. When the stat fails, it allows the coolant to flow straight to radiator and causes the overcooling issue.

There are 2 different type of oil stats available on x-type: one being completely shut when cold, other allows small amount of coolant to pass. Older x-types has the one that allows coolant through. Later, Ford upgraded it and made a "completely-shut" one. You have the older thermostat model.

Overcooling is most definitely caused by faulty oil cooler thermostat. Just replace it with genuine Ford or Jaguar part. Aftermarket oil cooler stats might not work.

I had the same problem on my car. After trying 3 different stats from ebay, i bought a genuine one and problem solved

 

Hi

Thanks for your post.

I'm aware of the oil thermostat, my question was is it meant to be fully closed. I recently changed the stat to a eBay one and I was able to blow though it. It didn't work. So I got a genuine jag stat that did not allow me to blow through - this is not working either and the engine runs cold down hill and warms up if I put my foot down 🙈

 

Does anyone know if replacing the main stat with a europarts would make a difference ?...in my trouble shooting I've changed the main stat but am thinking about getting a jag one and putting that in...id have changed both stats with jag ones then ??

Any help is appreciated !!!