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Temperature problem...

12K views 33 replies 5 participants last post by  Gibbo 
#1 ·
I have some problems with the temperature om my 306 1.6
When driving with low revs the temperature is "normal" 90. But when driving on motorways or with higher revs the temperature rises to around 95-110c. If i slow down, the temperature slowly decreases.
When standing still the temperature also rises to around 100-110c

I have changed the radiator, thermostat, temperature sensor (gauge) and cooling fluid. But that did not work.

-The water on top of the radiator is hotter than the bottom.
-I have a steady flow of hot air from the vents.
-When undoing the bleeding screw on the hose to the bulk head, i get a stream of water which strength follows the revs. (Rules out water pump?)

Any ideas?
 
#4 ·
Not always. On my 1.4 petrol 306 a bad earth made the STOP light flash on screen.

On my 2L diesel 306 the brake warning light stayed on for 5 seconds after starting.

On my 307 it made the power steering heavy.
 
#8 ·
Update
I have new earth cabels, and gone over the connections to the gearbox and chassis

I have now got both fans running.
When i unplugg the brown coolant fan sensor both fans starts at low speed for a few seconds, then high speed.

According to this workshop Cooling Fan when the engine is running, the low speed should kick in at 97 and the high speed at 107. But my fans does not kick inn on low speed before the gauge shows close to 110.

What could then be wrong? Could it be related to the cooling fan control unit in the wheel arch?
 
#9 · (Edited)
Update!

Her is an update on my problem. I could really need som inputs, since i am stuck...

The problem:
-The temperature gets to hot. 100-110c

-Driving up a hill makes the temp rise and goes slightly into the red, costing down the other side makes ti go a little bit down again

-Unplugging the fan coolant sensor so both fans operate at full speed does not help
-If i open the bleeding screw on the hose to the bulk head i get a steady stream of water that follows the revs. (Rules out waterpump???)
-I get a steady flow of hot air from the heater.
-I do not lose any coolant

The low speed fan that should kick in at 97c does not kick in before temp gauge shows appr. 105-107c
High speed fan should kick in at 107,c but it does not engage.

What i have done:

-Changed thermostat=no difference
-Changed radiator + coolant= no difference
-Changed temp sender to gauge and temp sender to fan ECU= no diffence
-New earth cable from gearbox and battery= no difference
-Cleaned cable connection the the fans=no difference
-Tried another (used) fan controll unit ECU (Bitron) = no difference

I im stuck with this problem, so if anyone have any ideas on what could be wrong let me know :)
 
#10 ·
I found i nice guide on another forum that i used to controll the signals to and from the Bitron unit.
In my case everything works fine, so bad wires to and from the Bitron unit can be ruled out.


Unplugg the Bitron unit and you will se that all the pins on the connector is numbered.


Earth pin 1= both fans on slow speed
Pin 4 = permanent 12v
Pin 15 = switched 12v
Ignition to ACC and earth pin 10 and 1 = both fans on high speed
Resistance pin 7 and 14 = cold engine around 1,9ohm. Hot engine around 3,5 ohm (confirms good temp sensor also)
 
#12 ·
so was the thermostat not opening? on my old 307 (2ltr petrol) after first start in the morning you could watch the temp guage get to around 95 ish then as the thermostat opened it dropped to about 80 or lower as the car heated up and stayed at a steady 90 all the time until in traffic when it would get hot and fans come in.
 
#13 ·
The weird thing about it is that both the old and the new thermostat opens when i heat them up. But when they are in the car, the engine runs to hot...

Thermostats work, but engine runs to hot
Without thermostat engine runs from 70-90c

I have ordered a original Peugeot thermostat to see if that helps. The other one was from a another auto shop, but they have quality parts. So i dont really think thats the problem, but have to try it anyway.

Any thoughts??
 
#15 ·
Update!

I have tried 3 different thermostats, but no change....

I wanted to check if the gauge could be the problem.
I bought a digital fluid thermometer and stuck it in the expansion tank.
The thermometer shows quite an amount lower than the gauge.
When the gauge shows 100c the thermometer shows around 85c. (If the water is 100c then it should have boiled right? It did not!)

When the gauge showed almost 110c, the thermometer showed about 93c. Thats also when the low speed fan kicked in. (The low speed should kick in at 97c)
Am i right to believe that the water temp around the faan sensor is a couple degrees higher than in the expansion tank?
If so, i think my cooling system and fans work and that the gauge shows to high.

Any thoughts?
 
#18 ·
Could be water pump. Impellers can come lose which then reduces circulation which only shows up when engine generates extra heat when under load as it cannot circulate water quick enough to stop temps rising.

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#20 ·
Have you flushed cooling system with rad flush etc. Could be a build up of scale in system. My 307 used to rise from 80 ish to just over 90 when on the motorway. It has done over 200k miles when I last changed belt and pump I put rad flush in about a week before and afterwards no change in temps and quite a bit of crud came out when I drained it and now constant temps

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#26 · (Edited)
I let the flushing product in for 6 days. Then i drained the system. I could find some particles in the water.

Then i flushed the system again just with the garden hose, then topped it up with just water and bleed the system.
Then everything seemed to be in order! The temperature was stabile 85-90 no matter if it was a hill or the motorway. So i was very satisfied.
I drove with just water in the system for two weeks with nice stable temperatures.
Since everything seemed to work, i decided to add coolant today. So i drained the system again and topped it up with 50/50 water/coolant and bleed the system.

But then suddenly i was back where i started!!!!

When driving uphill or pushing the engine (motorway) the temperature rises to 95-100. The same problems i had before, just not so high temperatures (100-110)
Standing still idling the temperature is just under 90.


Now i am just frustrated and fed up!!

Any ideas? Why is it happy with just water, but when i use water/coolant i have problems?
 
#28 ·
What is the correct order of the bleeding valves?
I know there is one valve on one of the hoses going through the bulk head and one on the thermostat housing.

There is also two valves on the right hand side of the radiator (standing in front of the car) on on top close the the hose and one on the buttom.
But these valves i do not get any water out of. I can anly turn them about 90 degrees before they stop, and they come upwards while turning.
I do not dear to force them by turning them more or try to pull them out in case i break anything. The radiator is brand new, so that would be a bummer...

Here is a picture of one of the two radiator valves:¨

 
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