C4 blows colder on the passenger side

[Hell Razor5543]

I would be VERY surprised if the hot air got THAT hot. On my C5 I can set the dual zone temperature to 28C on each side, but no hotter. If the windscreen was aggressively heated in very cold weather it could damage it.

40 degrees WHAT? If you mean 40F that is very cold (again, on my C5 the lowest temperature I can set is 16C (which is 61F)).

[GiveMeABreak]

For information James, the Temperature numbers on the control panel are not in degrees of any kind, they are incremental 'setting' numbers only, not a unit of temperature.

[GiveMeABreak]

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.

Like anything, that's the official way of doing it to ensure the system is bled and degassed, (especially the heater matrix), or there can be an air lock in the system. I just put up the procedure for the C4 as Cutac had already filled the cooling system and it would seem that's when the temperature variance happened - so the logical thing to check I suspect.

[Hell Razor5543]

Ah, I did not know (and, as my C5 appears to show the temperature in a recognised format, I believed that the numbers were in degrees).

[Cutac]

I've obtained the step by step procedure for the heating radiator replacement. Doesn't seem hard at all, biggest possible problem is flooding the interior.
I did around 700 kilometers since the coolant flush and air pocket must've gone by now, right?
If so, seems I'll have to replace the radiator. What on Earth could've happened to it during the coolant flush and thermostat replacement?

[myglaren]

Can you access the hoses under the bonnet and backflush it?
Could be some crap has lodged in the matrix.

[Cutac]

I can access the hoses, but what do you mean by backflush? Force the water the opposite way? I don't have a tool I could use to do that.

[Hell Razor5543]

I believe a way to backflush the coolant system is to secure a hosepipe into the lowest coolant pipe and then turn the water on. Mind you, I could always be wrong.

[moizeau]

Can you see the heater matrix hoses on the bulk head in the engine bay? If so, and you gain easy access you could flush just the heater matrix with a hose pipe?

[Cutac]

Hell Razor, oh right, good idea! Should've thought of that myself
I'll try that tomorrow.

Thanks for the idea!

[Cutac]

Nissens radiator is 190€, while NRF one is 53€(my friend can give me a big discount on the NRF).
Is NRF a good manufacturer?

[Cutac]

Since we've touched upon bleeding the cooling system, I'll ask here.
I've changed my heater matrix and it was fine until today. It was blowing cold so I floored it and it started heating. That means there's some air in the system. I did bleed it properly when the new matrix was fitted, so how come there's air in the system now?
Could it be that it was stuck somewhere and now it's made it's way to the matrix or something? Should I bleed it again or should I just drive the car for a few hundred kilometers? I've got a business trip on Thursday which will include 200 kilometers of 150kph motorway driving and 150 kilometers of somewhat spirited B road driving. Could that do the trick?

[Waynny]

Hi
I seem to have the same issue on a C4 picasso. Its blowing cold on passenger side on a R/H drive. How do you check if the heater flaps are working?