Duratec cooling fan operation

[JNC]

Air lock ! My car was the same I changed the thermostat to 82c and still had problems, it wasn't until I jacked the front of the car up so the expansion tank was higher than the heater then ran the car to bleed the air out , it worked a treat. I have fitted a bleed T up by the heater now so I don't need to Jack it up now , I can fill the system from the T.

[7 wonders of the world]

JNC,

This post refers to Duratec installations (rather than K series) which have the expansion bottle on the bulkhead so jacking the front isn't required.

 

The Duratec 82 degree stat can be bought through Opie with the club discount comes to £29

Part number is    -   Mahle TI 200 82

 

[JNC]

Yep Duratec ! The expansion tank is just behind the radiator in front of the engine and its lower than the heater !, that's why I jack up the car so the expansion tank is higher than the heater, thus the air rises to the highest point. My car is a 2012 Duratec roadsport 220 RBTB's 

+ when I bought my thermostat from CC it was cheaper than £29

[aerobod - near CYYC]

One thing that should be checked on the Duratec in an R400 is that the temperature that Easimap is reporting is accurate relative to the temperature on the sensor body when the cooling system has equalized to a somewhat steady state. I found on my R400 that the temperature gauge was actually showing a more accurate temperature when tested with a laser thermometer, compared with what Easimap was reporting, bearing in mind the gauge and ECU are using different sensors, although they are close together.

Although the temperature sensor mapping curve can't be changed is the standard ECU, it can just be accepted that 98C detected by the ECU may actually be closer to the high 80s, if the thermostat and fan are operating correctly. I actually swapped the locked ECU for a 9A4 unlocked one and have accurately mapped the temperature sensor curve. Now my fan accurately cycles on at 90C and off at 85C, as indicated by both the temperature gauge and Easimap.

[JNC]

Yep , agree with above. But thread reports difference in radiator hoses temperature obviously there should be some difference showing the cooling effect of the radiator ! But not cold. To me that shows lack of circulation of coolant. Air lock

[7 wonders of the world]

CC price on the 82 degree stat is now £36, stock version is £29

https://caterhamparts.co.uk/other/4378-thermostat-82-deg-c-r300-race.html?search_query=thermostat&results=12

 

 

[slap_ed]

Does anyone know if the DURATEC stock engines supplied by Ford to Caterham have the thermostat already fitted, or is the thermostat chosen and fitted by Caterham themselves?

If it came from Ford already fitted, then obviously Ford know what they are doing and have a fully tested reason as to why this range/temperature of thermostat was needed. I think most of the mainstream thermostats available today come in the following ranges of 74, 82, 88 and 92 degrees. Logan said that the original thermostat removed from his engine didn't have any temperature markings. I'm guessing that it's probably a 92 deg which is quite close to the fan switch on temperature of 97/98 deg which is why Logan suggests that the fan coming on is allowing the thermostat to only partially open, therefore making things difficult for the engine to cool, hence leaving the bottom hose cool to touch. 

If we change the thermostat down to a 82 deg, it then takes it out of Ford's specification. On start-up, the engine will start to cool sooner and not reach its intended temperature which has premature wear and internal condensation issues etc. Are we not masking the problem in that it could be the fan cut-in temperature not being high enough? This would then allow the thermostat to open fully and then hopefully allow the radiator to do its job and cap the rising temperature? I know this is locked away in the ECU and can't be adjusted.

Or am I talking bo**@cks?

[dave_h34]

Just done this mod and all looks well, radiator hoses now warm in advance of the fan kicking in rather than at the same time. Thanks to the advice in this thread, I popped over to Opie to save a few pennies. And indeed i did! Rather than going with the version with the shorter connections as per the Caterham part (£32 reduced to £21 on Opie) i went with the version with the same length connections as that already fitted, at a whopping £11.50!!: https://www.opieoils.co.uk/p-91277-integral-thermostat-mahle-ti-202-82.aspx Bargain upgrade! Interestingly, supporting info i'd seen elsewhere, and answering the post above, the part came labeled for Mazda. As i understand it, the engine when fitted by Ford has a 88/92/98 thermostat, even with electric actuation by the ECU on some versions, whereas Mazda fit 82ºC stats. If Mazda are happy to operate the engine at that temperature then i wouldn't have any reservations about operating outside of manufacturer's recommended range. Cheers.  

[slap_ed]

Hi Dave,

I’ve also done this mod a few months ago. Changing it to an 82 deg stat solves the problem of the fan coming on too often whilst the original stat was opening. Now the temperature remains stable below the fan cut-in temperature for most of the time. It’s only when sitting in traffic that the fan comes on, which is what you’d expect and now the bottom hose get hot which was only ever luke warm before. Result I say.

[7 wonders of the world]

The 82 degree non heated stat is a  Ford part as it is used on certain Ranger models, this is the same stat used by Cosworth on their performance crate engines.

This will open at 82 degree which will help maintain a lower level of engine temperature.

If the fan operation is a concern then look to its operation control method either by conventional single or twin stage fan switch or via ECU control.

If your using an Emerald the cut in and out temps can easily be adjusted by the end user.

 

[dave_h34]

The fundamental problem is incorrect calibration of the temp sender in the ECU, at the time the ECU reports ~98C and kicks the fan in, the real temperature is such that the 88/90C thermostat is only just beginning to open. Correcting the faulty setting in the ECU is the sensible answer, but it's a locked MBE and Caterham seem to think it's an acceptable situation. Using an 82C stat is a cheap workaround for the problem of the fan kicking in all the time. It of course doesn't fix incorrect temperature within the ECU but that seems not to cause a particular problem.

[ChrisC]

In my car the cooling fan was running when the ECU (via the MBE lead) was reading 99C, but the lower hose was still cold, no water was flowing around the rad so switching the fan on was pointless.  The temp climbed to 107/8ish before levelling out.   

The fan basically ran all the time, regardless even driving at a steady 30mph.  Wearing the fan our for no reason.  There is no adjustment from a consumer point of view, so the swap to 82C stat pulls all the temps into line, I.e. the stat opens before the fan switches on, giving the cooling system chance to do its job.