Hello I've got a problem with my 2011 cmax 2 1.6L TDCI 85hp that I hope somebody might have some insight into.

The car during this last cold period -7c to + 7c would after 30 mins mixed driving local roads & highway speeds would reach operating temp at motorway speeds (the needle in the middle of the temp gauge around 82 C), then when going back to local roads drop off the gauge to around 68c. 

I still get heat in to the cabin.

So I spent an afternoon fitting a new thermostat, that made things worse, now it never reaches the OT. It fluctuates constantly and hangs around at 75c and when idling drops off the gauge (60-68c), today at idle after 20 mins mixed driving. It dropped off to 50c outside air temp 6 c 

I have bled the system 3 times, fairly confident that it's not an airlock. saw the air returning to the expantion tank on first bleed, checked bleed nipple on thermostat, run /revved engine without cap on expansion tank etc. 

I'm still getting heat in to the cabin. 

It's not leaking, no loss of coolant.

measuring thermostat housing with IR thermometer is within 10 degrees difference to the engine diagnosis mode built in to the car, so suspect it isnt a temp sensor fault, the coolant really isn't getting hot.

Min68 with cabin heading on

Max 77c with cabin heating off 

Fan not running.

coolant in expansion tank heats up, so coolant is cirulating (heat in to cabin too)

Radiator temp 19c measured with IR thermometer. I have read that some coolant, a small amount goes to the radiator even when its fully closed, dont know thats a fact though. although looking at images of the part there is a small distance left for the coolant to flow. 

Have read that the oil cooler might be defective and bleeding off heat but its watercooled so it would heat the coolant?

No oil in the coolant.

No coolant in the oil.

there is oil in the engine. its not milky looks fine. doesnt look to have dropped in fill level. no extra smoke from exhaust.

the only event of significance thats happened within the last few years is in August i had an injector break that was replaced and the other injectors were running a bit rough so they were cleaned with a chemical in the fuel and it runs OK, it stars first time everytime regardless of outside temp. 

Whats left to look at? not producing enough heat? incomplete burning? (but no abnormal exhaust gasses)

I'm at a loss, maybe the new thermostat is defective?  is that really the cause? 

Thankfull for any help with this 🙂 

Can you send a link to the new thermostat?  They might be available at multiple operating temperatures.

Hi thanks for replying, it was a bit hard to find online, the shop that sold it had it named slightly differently to Vernets own site.

I bought it from this company.

https://www.mekonomen.se/termostat-gates-12652928

It says opens at 83c

I think think this is the correct page on Vernets catalogue page. 

also states 83c
https://www.ecalorstat.com/produit/TH7087.83J/?market=europe

 

 

1 hour ago, Semax said:

Hi thanks for replying, it was a bit hard to find online, the shop that sold it had it named slightly differently to Vernets own site.

I bought it from this company.

https://www.mekonomen.se/termostat-gates-12652928

It says opens at 83c

I think think this is the correct page on Vernets catalogue page. 

also states 83c
https://www.ecalorstat.com/produit/TH7087.83J/?market=europe

That is the right one.  And a decent brand, Gates.  I suspect it is faulty and would try another one before looking for a separate fault.

Thanks for the advice, before I do that if you've got the time I'd apreciate it, I've been busy, I now remember that I was on a trip in early spring and we had a heatwave, the misses had the car and the compressor and condensor blewup, so she got it repaired. it worked fine, engine temps were fine till it got really cold a few weeks back. Could anything associated with that be causing a problem?

I did a bit more research last night, i took the old thermostat and slowly boiled it in water several times to see if it was broken and it isnt, it begins to open at 83c and is wide open at 87/88C although I understand that it could have been sticking open right up to the moment I took it off the engine. 

I downloaded Forscan and borrowed an ODB2 Cable and this morning took a live recording of anything I could see to do with temperatures, and see a couple of things,first the initial coolant temp after 12 hours since last run and parked outside in 6c airtemp shows 15c, is that the lowest it can record? or is that a fault? Also that there are a 2 different temperatures recorded for coolant temperature ,"engine coolant temperature" and "coolant Temperature" I will paste the full forscan reports below. Not only are they far too high they initally dont match, 14c and 16c tells me potentially there are 2 temperature sensors? Also there is about 0.4 of a second between the first ECT (the one with initially no reading) and the second one updating, perhaps a scan lag in the reading in of values? Also both ECT readings are consistantly 2 degrees above Coolant temp. Is this normal?

pre engine start.

COOL_TEMP "no reading" Coolant Temperature
ECT    16 °C    Engine coolant temperature
ECT     "no reading"    Engine coolant temperature
ECT_V    3.39 V    Engine coolant temperature sensor voltage
 

5 seconds

COOL_TEMP    14 °C    Coolant Temperature
ECT    16 °C    Engine coolant temperature
ECT    16 °C    Engine coolant temperature
ECT_V    3.37 V    Engine coolant temperature sensor voltage

After 5 mins

COOL_TEMP    50 °C    Coolant Temperature
ECT    52 °C    Engine coolant temperature
ECT    52 °C    Engine coolant temperature
ECT_V    1.61 V    Engine coolant temperature sensor voltage

@20 mins

COOL_TEMP 75 °C Coolant Temperature
ECT 77 °C Engine Coolant Temperature
ECT 77 °C (Engine Coolant Temperature
ECT_V (Engine Coolant temp sensor voltage) 0.81V @75c/77c (3.35V @ 6c ambient T)

Do you know if the coolant temperature gauge is the only sensor monitoring engine temp? 

Yesterday evening I warmed up the car as much as possible for about 45 mins whilst parked, at some point I had turned the blower fans off and whilst revving to around 1400RPM I can hear an intermittant very soft quite fairly high pitched squeak that kind of has a repeatable pattern 1.....2..-3-4-5....1....1................... like a little bird, its so soft you cant hear it with the fans running. and its infuriatingly vague when trying to locate it in the engine bay, it sound like it come from everywhere. I have a recording if it would help.

I took the car out for some progressive driving for an hour and it wouldnt go over 78c and it really should have done. it flatlined at 77c.

Is the front radiator the only way for the car to dump waste heat?

Also on Forscan and I dont know if these values are default (ie the car doesnt have that sensor) but some of these these never change and others with exactly the same name name and description have unresonable values;

INCARTMP 23c External Temperature from sensor (outside temp 6 degrees, dashboard thermometer display shows 6c)
INCARTMP 86c goes up to 96c after 5 mins then to 109c after 10 mins
OUTTMP 23c internal temp. from sensor Always 23c

IAMT 6c when cold (internal ambient temp)

preignition

OUTTMP         External Temperature From Sensor
AHS         Add heat status
COOL_TEMP         Coolant Temperature
INCARTMP         In car temperature
OUTTMP         External Temperature From Sensor
WPS         Water pump status
WPUMP_AHCM         water pump
INCARTMP         In car temperature
INCARTMP         In car temperature
OUTTMP         External Temperature From Sensor
AIRTEMP_RF         Discharge Air Temperature, Right Floor
AIRTEMP_RP         Discharge Air Temperature, Right Panel
IAMT         Internal Ambient Temperature
ENGCOOLNT         Temperature Gauge
INCARTMP         In car temperature
ECT    16 °C    Engine coolant temperature
ECT         Engine coolant temperature
ECT_V    3.39 V    Engine coolant temperature sensor voltage
EGR_POS_SEN    4.48 V    EGR Cooler Bypass Position Sensor Voltage
EGR_VAL_DES    99.96 %    EGR Cooler Bypass Valve Position - Desired
EGR_VAL_MEA    99.96 %    EGR Cooler Bypass Valve Position - Measured
PHSC         Parking heater start count
DLA_SED_FD10_BY_1_PID         DL_SED_FD10_BY_1_PID
RUNTM    175 s    Time since start (s)
ACRPSV         Air Conditioning Refrigerant Pressure Sensor A Voltage
CylBal_1        Cylinder 1 Contribution/Balance
CylBal_2         Cylinder 2 Contribution/Balance
CylBal_3         Cylinder 3 Contribution/Balance
CylBal_4         Cylinder 4 Contribution/Balance
INJ_LRN_C1         Injector Pilot Learn Cylinder 1
INJ_LRN_C2         Injector Pilot Learn Cylinder 2
INJ_LRN_C3         Injector Pilot Learn Cylinder 3
INJ_LRN_C4         Injector Pilot Learn Cylinder 4
INCARTMP         In car temperature
INCARTMP         In car temperature
FAN_AHCM         Combustion Air Fan
BSO         Blower Speed Output

10 seconds from ignition

OUTTMP    23 °C    External Temperature From Sensor
AHS    OFF     Add heat status
COOL_TEMP    15 °C    Coolant Temperature
INCARTMP    23 °C    In car temperature
OUTTMP    23 °C    External Temperature From Sensor
WPS    ON     Water pump status
WPUMP_AHCM    On     water pump
INCARTMP    86 °C    In car temperature
INCARTMP    23 °C    In car temperature
OUTTMP    23 °C    External Temperature From Sensor
AIRTEMP_RF    6 °C    Discharge Air Temperature, Right Floor
AIRTEMP_RP    7 °C    Discharge Air Temperature, Right Panel
IAMT    6 °C    Internal Ambient Temperature
ENGCOOLNT    0.00 %    Temperature Gauge
INCARTMP    23 °C    In car temperature
ECT    17 °C    Engine coolant temperature
ECT    16 °C    Engine coolant temperature
ECT_V    3.36 V    Engine coolant temperature sensor voltage
EGR_POS_SEN    4.48 V    EGR Cooler Bypass Position Sensor Voltage
EGR_VAL_DES    99.96 %    EGR Cooler Bypass Valve Position - Desired
EGR_VAL_MEA    99.96 %    EGR Cooler Bypass Valve Position - Measured
PHSC    962      Parking heater start count
DLA_SED_FD10_BY_1_PID    Unfolded     DL_SED_FD10_BY_1_PID
RUNTM    185 s    Time since start (s)
ACRPSV    0.90 V    Air Conditioning Refrigerant Pressure Sensor A Voltage
CylBal_1    1.14465260      Cylinder 1 Contribution/Balance
CylBal_2    0.94669988      Cylinder 2 Contribution/Balance
CylBal_3    0.96861324      Cylinder 3 Contribution/Balance
CylBal_4    0.94071796      Cylinder 4 Contribution/Balance
INJ_LRN_C1    7      Injector Pilot Learn Cylinder 1
INJ_LRN_C2    7      Injector Pilot Learn Cylinder 2
INJ_LRN_C3    7      Injector Pilot Learn Cylinder 3
INJ_LRN_C4    7      Injector Pilot Learn Cylinder 4
INCARTMP    23 °C    In car temperature
INCARTMP    23 °C    In car temperature
FAN_AHCM    Off     Combustion Air Fan
BSO    29.80 %    Blower Speed Output
    

5 mins after ignition

OUTTMP    23 °C    External Temperature From Sensor
AHS    OFF     Add heat status
COOL_TEMP    50 °C    Coolant Temperature
INCARTMP    23 °C    In car temperature
OUTTMP    23 °C    External Temperature From Sensor
WPS    ON     Water pump status
WPUMP_AHCM    On     water pump
INCARTMP    95 °C    In car temperature
INCARTMP    23 °C    In car temperature
OUTTMP    23 °C    External Temperature From Sensor
AIRTEMP_RF    44 °C    Discharge Air Temperature, Right Floor
AIRTEMP_RP    26 °C    Discharge Air Temperature, Right Panel
IAMT    10 °C    Internal Ambient Temperature
ENGCOOLNT    0.00 %    Temperature Gauge
INCARTMP    23 °C    In car temperature
ECT    52 °C    Engine coolant temperature
ECT    52 °C    Engine coolant temperature
ECT_V    1.61 V    Engine coolant temperature sensor voltage
EGR_POS_SEN    1.69 V    EGR Cooler Bypass Position Sensor Voltage
EGR_VAL_DES    0.00 %    EGR Cooler Bypass Valve Position - Desired
EGR_VAL_MEA    0.00 %    EGR Cooler Bypass Valve Position - Measured
PHSC    962      Parking heater start count
DLA_SED_FD10_BY_1_PID    Unfolded     DL_SED_FD10_BY_1_PID
RUNTM    507 s    Time since start (s)
ACRPSV    1.01 V    Air Conditioning Refrigerant Pressure Sensor A Voltage
CylBal_1    1.00007936      Cylinder 1 Contribution/Balance
CylBal_2    1.00007936      Cylinder 2 Contribution/Balance
CylBal_3    1.00007936      Cylinder 3 Contribution/Balance
CylBal_4    1.00007936      Cylinder 4 Contribution/Balance
INJ_LRN_C1    7      Injector Pilot Learn Cylinder 1
INJ_LRN_C2    7      Injector Pilot Learn Cylinder 2
INJ_LRN_C3    7      Injector Pilot Learn Cylinder 3
INJ_LRN_C4    7      Injector Pilot Learn Cylinder 4
INCARTMP    23 °C    In car temperature
INCARTMP    23 °C    In car temperature
FAN_AHCM    Off     Combustion Air Fan
BSO    29.80 %    Blower Speed Output
                                                   

 

Sorry, I would like to help but that's just too much text for me to go through the whole lot.

Few points from skim reading:

The old thermostat opens at the correct temperature.  Perhaps you can check whether it is totally sealed when closed?  If yes, then I would re-fit that for now, there was nothing wrong with it.

Regarding the two coolant temp sensor readouts, as they are always exactly 2c out, one of them is not 'real'.  It is being calculated by the ECU.  15c might be the minimum temp the sensor can read, but coolant does hold heat so I wouldn't be surprised if it's warmer than ambient the next day after being parked.

The radiator is technically the only way the engine can lose heat.  However, it does also lose heat through the heater matrix inside the car, the more heat you require inside, and the faster the fan inside, the more heat will be taken from the coolant.

I totally understand 🙂 thanks for taking a moment to reply it's been most helpful and very insightful, much appreciated.