New owner 2009 207 1.4 thermostat/temp sender question

[admiral51]

Hi all
My son has just aquired the above mentioned vehicle vin VF3**************[VIN obfuscated, can be read by forum staff].
He says it never seems to get above 70 on the temperature gauge on a drive, although when stationary and engine running it will creep up past that towards 80.
Checked rad hoses and all are getting hot and heater works nice and warm,all direction settings work and will blow hot/cold as requested, A/C works fine.

It had a new clutch cambelt and water pump done in November, could there be an air block but then it would run hot ?
Have yet to put the Lexia on it as A it is not here and B i do not know the location of the diag socket

Any pointers would be great as he has only had it 4 days and i have been tied up with the water ingress in my Xantia

[GiveMeABreak]

Here's some info on the system incorporated into the TU3AE5 engine, which uses a piloted thermostat Colin.

Its role is to accelerate the engine temperature increase in order to improve the exhaust gas emission control and to obtain a higher engine operating temperature to reduce friction and fuel consumption.

The thermostat is open (whether in piloted or non-piloted mode if the temperature is above 105°C).

During normal operation, the thermostat is not piloted, it regulates the coolant temperature at 105°C.

For full engine loads:

• The injection ECU controls the regulation of the thermostat at 89°C
• The injection ECU controls the piloted thermostat heated resistor (26) in order to add the 16°C which the coolant lacks in order to melt the wax (25)

Time	Operating Phase	Description of the Operating Phase
t0 and t1	Partial load	The engine management ECU does not activate the piloted thermostat regulation control. The engine coolant temperature is regulated at 105°C guaranteeing a reduction in consumption
t1 and t2	Full load	The engine management ECU detects a full engine load and controls the opening of the piloted thermostat by means of the internal resistor which melts the wax, simulating a temperature of 105°C. The engine coolant temperature decreases and stabilises at a temperature of 89°C
t2 and t3	Full load	The engine cooling is regulated at an engine coolant temperature of 89°C in order to avoid an excessively high engine operating temperature
t3	Partial load	The engine management ECU detects a partial load and no longer controls the activation of the piloted thermostat internal resistor. The piloted thermostat again regulates the engine coolant temperature of 105°C

The piloted thermostat opening control is determined in relation to the following parameters:

• Vehicle speed (Guarantee of the performance of the engine cooling)
• Intake air temperature (Guarantee of the performance of the engine cooling)
• Ambient air temperature (Guarantee of the correct temperature under the bonnet in cold climates and of no adverse effect on the temperature in hot climates)
• Engine load
• Engine coolant temperature

Note: Bleeding of the cooling system uses a special injection ECU strategy.

Conditions necessary to inform the injection ECU of entry into a cooling system bleed phase:

• Zero vehicle speed (For 10 seconds)
• Engine speed above 1450 rpm (For 10 seconds)
• Engine torque below 5 m.daN (For 10 seconds)

Example of the reference speed of a dual speed cooling fan unit (in %)

Key:

• 50% = Slow speed
• 100% = High speed

The piloted thermostat opening control is determined in relation to the following parameters:

• Vehicle speed
• Intake air temperature
• Ambient air temperature
• Engine load
• Engine coolant temperature

The parameters of the cooling fan post-cooling triggering and duration map are set by the coolant temperature and the exhaust line temperature sensor.
The energy stored by the catalytic converter determines the activation of the cooling fan unit control.

[admiral51]

Thanks Marc
Looking at the ECU Strategy unless those conditions are met the thermostat would not open fully so therefore it may not have been bled properly .
Think the thermostat is easy enough to replace , just need to get the correct one.
So engine at idle for 10 secs, rev to 1500 for 10 secs then idle for 10 secs should be enough to tell the ECU to start a bleed phase.
If it gets here early enough tonight i will try and put the Lexia on it just to get some data and see if any faults are thrown up that do not light up the EML .
Is there a bleed screw or just header cap off like the good old days.
Assume the ECU strategy is aimed at not having to get the coolant up to temp to open the thermostat

Cheers
Colin

[GiveMeABreak]

Yes, a bleed screw as shown at 3:

This is a Euro 5 standard engine - so they run at higher temps to reduce emissions and get there more quickly.

[admiral51]

Thanks Marc i guess then that the temp staying around the 70 degree area is not correct, just i am used to the Xantia that never gets above the 80 mark

[admiral51]

Done a global test and apart from both speakers not working the only faults found are the below.

Not too worried about the BSI one, will do another Global over the weekend to see if the oxygen sensor pops up again.

Can i go into Diagbox and tell the ECU i want it to go to bleed system mode or trust that 10 secs idle, 10 secs 1500 revs and 10 secs idle will work ?

May just get a new Stat if they are cheap enough, seen a few that state 103 degrees opening that fit and others at 105 degrees so will need to keep an eye on part numbers and opening values + the electrical control opening.
Thanks in advance and for everything posted so far to help my boy out

Colin

[GiveMeABreak]

Ok, so the BSI one you can ignore.

P0137 is the Downstrean Oxygen Sensor signal fault: Short circuit to earth. The downstream oxygen sensor voltage is lower than 29 mV.

The engine ECU will deactivate the monitoring of the air intake whilst this fault is active and put up the engine management lamp and driveability will be downgraded.

The suspect areas are the Downstream oxygen sensor (ON/OFF), Electrical harness or Engine ECU. So the first stop is the sensor itself - the lower one on the diagram below:

Now a word of caution:

Although 1628NY is the original replacement part, they now suggest replacing it with part 1628TH. This has a longer cable and needs tying securely and away from the exhaust. On several PSA vehicles the original sensor cable is too short and gets burned by the heat from the exhaust, this then causes a short.

There are several technical service bulletins on this - and although not specific to the 207 - they have decided to roll this modification to affected vehicles and the 207 is included. So don't bother with the original part - it will just be building up to the same issue at a later date no doubt.

"A" Original Part - This is the original sensor "B" Modified part - This is the new part	"C" Fitting incorrect: The excess electrical harness is secured too close to the exhaust line (at " a"). "D" Fitting correct: Secure the excess electrical harness close to the connector (at " b").

Lastly, the stat is part: 1336Z2 and is £66.29 from Peugeot.

[admiral51]

Once again you are a star with detailed information.
I do not have the time of the fault with the sensor but looking at it the coolant temp is showing as 81 degrees.
Whilst i wait till the weekend to run another test and look at doing the bleeding procedure if the temp sensor is not too expensive would it worth getting one and replacing it as he has no history of it ever being done.
Reports from him today says the temp gauge barely moved above 70 degrees, albeit on a short 16 mile run in stop start traffic.
Colin

[admiral51]

Just a quick update
Tonight it seems that whilst driving the car it sat around the 70 degree mark whilst in heavy stop start traffic and then leaving it running whilst chatting to a friend he says the gauge went up close to 90 degrees.
Any thoughts before i shell out hard earnt cash

[admiral51]

Yes, a bleed screw as shown at 3:



This is a Euro 5 standard engine - so they run at higher temps to reduce emissions and get there more quickly.

Marc do you know the part number for #5 which i think is the coolant temperature sensor if you have a spare 5 minutes.
Thanks Colin

[GiveMeABreak]

Replacement part: 9636777180 Original is £54.14 from Peugeot Colin inc.

M12 X 150 2 Pin Green.

[admiral51]

Thanks Marc

[admiral51]

Update and all tests done stationary in driveway
Some good news some not lol
Done another Global test, only faults showing are the rear speakers which is nothing to worry about, oxygen sensor not showing so fingers crossed.
Still learning with Lexia but did manage to find the engine ECU and managed to check live data on temp and cooling fan operation.
The engine temp seems fine, watched it go from 52 to 89/90 and then slow speed kicked in followed by full chat and temp dropped to 83, fans then switched off, fast first then slow fan.
The problem is that until engine temp got to 65 or so the gauge was not moving, then it decided to play catch up, finally matching engine temp at 76 degrees then over reading to 90 when engine was showing 80.
It then behaved and stayed at 90 until fans kicked in and dropped to 80 and then crept back up to 90 when fans had stopped.
I then turned A/C on and watched fans kick in and engine temp drop all the way down to 74 degrees, but the temp gauge followed it all the way down to 74.
My understanding is that the gauge should show a steady reading, any where between 80-90 and only show true temp if there is a problem ?
Going to take it for a live test data drive tomorrow to see what engine temp really is compared to gauge.
Thanks for all the help so far really appreciate it
Colin

[admiral51]

Really going to need some expert help now.
Have taken it for a test drive and got some live test data which is now concerning me.
The engine temp never got above 63 degrees and gauge was showing correct reading.
Sat in a lay by and revved till engine temp got 80 degrees drove off and engine temp dropped back down to 63

In the first pic it shows the coolant temp reference value as -40 degrees, that was from the previous stationary test.
In the next 2 pics it shows the driven test, and although it shows the reference as 105 degrees in the test this value was -40 not the 105 showing ??
Also the controlled thermostat value is 02 no idea what that means.
Hoping what it means is that the stat is fully open.
Over to the experts
Thanks
Colin

[admiral51]

Prepared to be shot down in flames here but most of you know my logic
We know that the stat is set to open at a certain high temperature to aid cooling, but would a stat need to be fully open at a significantly low temperature to stop coolant freezing ?