C4 blows colder on the passenger side

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Cutac
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C4 blows colder on the passenger side

Post by Cutac »

Hello

I've changed thermostat yesterday and according to my passenger, it's started blowing colder than before on the passenger side.
It definitely does blow hotter on the drivers side but the temperature on the passenger side changes with the dial.
It's like this:
When set to high, driver's side blows 40°C air but passenger side blows 25°C air.
When set to low, driver's side blows 20°C air but passenger side blows 5°C air.

Flap works and temperature does change but the temperature range is wrong.
Note, it was fine before coolant and thermostat change.
Also, now the driver's side blows hotter on max than it did before the ts job.

EDIT: it's LHD car, so my passenger would be a driver in the UK.
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GiveMeABreak
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Re: C4 blows colder on the passenger side

Post by GiveMeABreak »

The heater installation is the same for both RHD & LHD vehicle’s, although we over in the U.K. do have a slightly easier job on replacimg common items on the system as there is no steering wheel or pedals to get in the way.

My first thought would be to ask if the system was bled properly after you replaced the coolant. If there is air in the system it could be affecting the heater matrix and the heat output.

I can’t remember off hand whether you have dual zone climate on this model (I’m away from the other system), but if you do, what happens if you put the drivers side to cold and the passenger side to hot? What is the temperature on the passenger side?

If it is still only in the 20 °C range, then I would still suspect that the air mixing flaps are not fully changing position. On Dual Zone systems there will be 2 air distribution stepper motors and 2 air mixer stepper motors.
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Cutac
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Re: C4 blows colder on the passenger side

Post by Cutac »

I don't know if it was bled properly. I did bleed it on the heater bleed valve and on the thermostat, but there still could be an air pocket trapped inside, right?
Also, I'm pretty sure it blows hot air while I'm accelerating so that would mean there's air inside?

Flap is not faulty, that's the first thing I suspected since I had the flap cog fail on the VTS.
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xantia_v6
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Re: C4 blows colder on the passenger side

Post by xantia_v6 »

There is only one heat exchanger (matrix), so if it is blowing 40° out one side, there is nothing wrong with the water circulation. The difference in temperature between left and right is entirely controlled by the ecu driving the mixer flaps.
You have not said whether your temperature numbers came from diagbox or an independent thermometer.
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Cutac
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Re: C4 blows colder on the passenger side

Post by Cutac »

Umm, they are random, really :mrgreen:
But the ratio is correct. Both sides change the temperature but passenger side is always lower by the same amount.

Diagbox can read out air temperature?
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GiveMeABreak
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Re: C4 blows colder on the passenger side

Post by GiveMeABreak »

No, Diagbox can’t measure the cabin heater temp.
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Cutac
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Re: C4 blows colder on the passenger side

Post by Cutac »

Alright, thanks.

I'll be bleeding it in an hour so will let you know how it goes.
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Cutac
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Re: C4 blows colder on the passenger side

Post by Cutac »

Let it run for 25 minutes with no exp tank cap, opened ts bleed valve twice(first time coolant was dripping, second time it didn't), and opened cabin bleed valve.
Still no heat.
I'll drive it like that for 10 days maybe it gets better.
What the hell could be wrong with it? Why does the c4 hate me?
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Cutac
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Re: C4 blows colder on the passenger side

Post by Cutac »

Update:
Gained access to the cabin heater radiator. One pipe is hot(lower one, from the engine), and I mean it, hot, and the other(upper one, towards the engine) is barely warm.
Could it be that the radiator is plugged?
As I see, it takes 4 bolts and 2 clamps to remove the radiator. Is the job really that simple?
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GiveMeABreak
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Re: C4 blows colder on the passenger side

Post by GiveMeABreak »

Well this is the official procedure for Draining, Filling & Degassing:

Official Tools
Cutac Bleed D.PNG
Cutac Bleed D.PNG (100.81 KiB) Viewed 890 times
Cutac Bleed E.PNG
Cutac Bleed E.PNG (30.39 KiB) Viewed 890 times
Cutac Bleed F.PNG
Cutac Bleed F.PNG (28.51 KiB) Viewed 890 times
Tool for filling the cooling system by vacuumBayonet filling cylinderAdaptor / extension for bayonet filling cylinder [0173]
Cutac Bleed G.PNG
Cutac Bleed G.PNG (14.39 KiB) Viewed 890 times
Cutac Bleed H.PNG
Cutac Bleed H.PNG (36.32 KiB) Viewed 890 times
Cutac Bleed I.PNG
Cutac Bleed I.PNG (61.98 KiB) Viewed 890 times
Blocking Rod for Filling CylinderScrew-fit Filling Cylinder (without extension)Cable Pliers for Flexible Clips


Draining the cooling system
CAUTION: The draining operation is carried out with the engine cold.

Put the vehicle on a hoist.
Remove:
  • The protective panel under the engine (according to equipment)
  • The de-aeration chamber plug (Carefully)
N.B.: Place a clean tray underneath the engine to recover the coolant.
Cutac Bleed A.PNG
Uncouple the pipe (1) (at "a"); Using tool [0165-2].
  • Open the bleed screws located on the coolant outlet housing and the heater pipe.
  • Allow the coolant to run out.
  • Drain the cylinder block (if necessary).
CAUTION : If the tool for filling the cooling system by vacuum [01102] is used, measure the quantity of coolant drained.

Filling the cooling system

CAUTION:
  • If the cooling system is contaminated, rinse with clean water.
  • Always use new coolant.
  • Each filling operation must always be followed by a cooling system degas operation.


Filling the cooling system by gravity
Connect the hose (1) (at "a"); Using tool [0165-2].
N.B.: Refit new clips.
Cutac Bleed B.PNG
"A" : Fitting with filling cylinder offset; Using the tools [0173], [0173-B], [0173-C].
"B" : Fitting with filling cylinder direct; Using tool [0173-2].
  • Fit the filling cylinder, blank and adaptor assembly on the expansion chamber (according to assembly).
  • Open the rod on the filling cylinder.
  • Slowly fill the cooling system with clean coolant.
  • Close the bleed screw when the fluid is flowing freely without any air bubbles.
N.B.: The filling cylinder should be filled to the 1 litre mark for correct bleeding of the heater matrix.

Filling using the tool for filling the cooling system by vacuum

CAUTION: Always use new coolant.
Connect the hose (1) (at "a") ; Using tool [0165-2].
N.B.: Refit new clips.
  • Close the bleed screw.
  • Put the equipment for filling by vacuum [01102] in place on the expansion bottle.
CAUTION: To avoid entry of air into the circuit, provide for 20 % additional coolant.
Prepare a receptacle of coolant containing the quantity of fluid drained + 20 %.
N.B.: The receptacle must be positioned slightly lower than the equipment for filling by vacuum.
Cutac Bleed C.PNG
  • Place the cooling circuit under a vacuum to reach -0,9 bar (diagram "C") :
  • Wait 10 seconds and check that the value obtained does not drop
  • Fill the cooling circuit completely and wait for the return to 0 bar (diagram "D")
N.B.: The quantity of coolant filled should correspond to the quantity of fluid drained.
Repeat the operation until the cooling system is full (if necessary).
CAUTION: Remove the equipment for filling by vacuum [01102] and rinse the assembly with clean water.

Degassing and Checking the Cooling System
  • Fit the charging cylinder, closer and adaptor assembly on the expansion bottle, in the case of draining using the tool for filling by vacuum [01102].
  • Open the rod on the filling cylinder.
  • Start the engine.
N.B.: The air conditioning control should not operate during this phase.

All Engines Except EURO 6 Emission Standard (This is for your 180 Cutac)
Keep the engine speed at 1500 - 2000 rpm, up to the second cooling cycle (cooling fan(s) cutting in and out).
CAUTION: Check that there are no coolant leaks.
Stop the engine.

ESSENTIAL: Do not remove the filling cylinder while the engine is hot.
  • Leave the engine to cool.
  • Blank the filling cylinder using the blocking rod .
  • Remove the filling cylinder , plug and adapter assembly.
  • Check the coolant level when cold.
  • Top up the coolant to the "max" level (Cold).
CAUTION: Do not fill the system past the max mark.
  • Refit and tighten the cap on the header tank.
CAUTION: Check that the cooling system filler cap is locked (For bayonet cap).
Refit:
  • The protective panel under the engine (according to equipment)
  • The vehicle to its wheels
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Cutac
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Re: C4 blows colder on the passenger side

Post by Cutac »

Thanks :)
Can you also find the guide to replacing the interior heater radiator?
6448 W8 is the code.
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GiveMeABreak
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Re: C4 blows colder on the passenger side

Post by GiveMeABreak »

Are we talking about your 180 here or the VTi? :-k

Edit: For that part number, it will be your VTI. Yes, I can prepare that procedure, but as it involves removing the accelerator and bracket and possibly the inflation detection ECU first, it will take a while. I'll get round to it as soon as I can :shock:
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Cutac
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Re: C4 blows colder on the passenger side

Post by Cutac »

VTi

Hmm, it seemed to me that it would be a simple process. Well, we'll see. Thanks, and you don't have to rush, I surely won't be doing it in the next few days as I don't have a spare part.
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GiveMeABreak
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Re: C4 blows colder on the passenger side

Post by GiveMeABreak »

Ok, I'll get round to it when I can - but like anything, I suspect there are shortcuts, but hard to tell with your left hand drive of course :-D
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EDC5
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Re: C4 blows colder on the passenger side

Post by EDC5 »

Just a question, shouldn't the hot air be a lot warmer than 40 degrees when set to hot?

I have changed the coolant in my C5 before and apart from opening the bleed valve I did not use any vacuum apparatus or anything else and it appears to behave itself.