mk2 Focus 1.6 tdci running even colder after thermostat change

[darthvincor]

Hi,

I have a 2006 mk2 Ford Focus with 1.6 TDCI engine, and for years it appears to have been running cool in winter, taking a long time to get up to operating temperature. And sometimes even cooling off when in traffic. In spring/summer/autumn no issues, also not overheating.

So I figured it was due to a faulty thermostat and replaced it with a new Ford part. And now it's running even cooler! It will barely get off the minimum mark, and if so only a slight bit when doing a hill climb. But then immediately drop back to the minimum again.

When draining the coolant 4 litres came out, and I put 4 litres back in. (fresh Ford coolant)

Also: heat out of the vents is not as hot as it used to be. At maximum heat, it's really quite modest.

Does anyone have an idea what's going on here? Is there air trapped in the system? I thought I added the coolant and water quite slowly.

 

Thanks,

 

Vince

[Albert27]

3 hours ago, darthvincor said:

Hi,

I have a 2006 mk2 Ford Focus with 1.6 TDCI engine, and for years it appears to have been running cool in winter, taking a long time to get up to operating temperature. And sometimes even cooling off when in traffic. In spring/summer/autumn no issues, also not overheating.

So I figured it was due to a faulty thermostat and replaced it with a new Ford part. And now it's running even cooler! It will barely get off the minimum mark, and if so only a slight bit when doing a hill climb. But then immediately drop back to the minimum again.

When draining the coolant 4 litres came out, and I put 4 litres back in. (fresh Ford coolant)

Also: heat out of the vents is not as hot as it used to be. At maximum heat, it's really quite modest.

Does anyone have an idea what's going on here? Is there air trapped in the system? I thought I added the coolant and water quite slowly.

 

Thanks,

 

Vince

Hi Vince.

What you're describing to me sounds pretty much normal for my 1.6tdci in regards to the coolness in winter, they take a lot of driving to get warm in low temps ad the gauge will drop easily!

If I recall correctly the Coolant capacity is 7.2 litres and it does sound like you've not put enough in.  You also need to bleed it, did you do this?  I don't know if that would affect your vents though.

[isetta]

I had 1.6tdci fiesta for 9 years (from when it was 5 months old) and never got much heat out in winter. max guage would go up was about one third. And it defintely did go down when stationary with engine running and heater fan on.

It's a sign of a very efficient engine. Heat is a by-product of an internal combustion engine which is waste and more heat means it is a less efficient engine. Engineers work on trying to make engines more efficient by reducing waste. Trouble is this engine is so efficient there is too little waste heat to take advantage of in winter.

Thank god a I had a quick clear windscreen. 

My current 1.5tdci is a bit better but does take a long time for temperature guage to move sometimes. My 1.5tdci has an undertray on engine bay, the 1.6tdci did not. I do not know how much difference it makes to heat, or whether it's there more for noise reduction.

 

[pragmatix]

Sounds like an air lck to me, 

[darthvincor]

Thanks for the replies. And sorry for the late reply on my part, things suddenly went down hill really fast. Took it to a mechanic, told them about the new thermostat and the lack of heat, and they checked it test drove it and looked in the computer all manner of codes erupted. Including the DPF, both check engine and systems fault lights (red one) went on. Also down on power prior to the codes.

Mechanic suggested we get rid of the car, and that the thermostat was probably fine. I have no idea what happened. Only mistake I made I think was to forget to plug the air flow sensor in after my thermostat change, which prompted a code or two, which I cleared and it seemed fine. Maybe this set in motion it's complete electric breakdown. Were also advised not to drive it anymore, as the DPF could clog up at any moment. (which is strange, considering it's quite new, from September)

Will try and read the codes, and report back.