02 c5 blower not heating (mechanical)

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n0stra
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02 c5 blower not heating (mechanical)

Post by n0stra »

My newly acquired low milage 02 number 2, a 1.8 petrol break, seems to be unable to fight the recent cold weather by blowing mostly cold air inside the cabin.

If I push the gas pedal and the engine has gotten hot, I can feel the temperature rising, but it's way to cold for normal use.

I have seen many threads about broken flaps on electric automatic climate systems being the reason for symptoms like these, but often then having a different temperature in various sides. My problem on the other hand is with a mechanical manual system without zones.

So Im asking if there are someone that might have a clue in what's going on and what the fix might be? Is there something as easy as wires behind the center consol going from the turn knob adjusting the heat?

I have checked the pipes going from the engine room into the car that I'm guessing is transporting heat, and the one closest to the brake system is quite hit while the other one is somewhat cooler.

Appreciate any input since the weather up here in Norway is now windy and minus 10 degrees.

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white exec
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Re: 02 c5 blower not heating (mechanical)

Post by white exec »

The two pipes carrying hot coolant to the cabin heater matrix should both be hot, and with only a fairly small temperature difference between them. If one is cold, then there is no flow through the heater matrix, which suggests it is blocked.
At the age of the car, it is probably time to replace the matrix, unless a reverse-flush with a hosepipe can clear it. Nissens brand has a good reputation.

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Peter.N.
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Re: 02 c5 blower not heating (mechanical)

Post by Peter.N. »

What is the water temperature reading?

Peter

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Re: 02 c5 blower not heating (mechanical)

Post by n0stra »

Perhaps I misphrased, none of them are cold, but I can notice a small difference when touching them lightly. I would not put my hands on any of them for a longer period of time.

As a Norwegian I'm unfamiliar with "heater matrix". Could you explain?

Anything done to this car has to be possible for an amateur to do on his own unfortunately since spending tons of cash (which services here in Norway cost, around 100 euro/pounds per hour plus parts) would defeat the purpose of owning a 500 £ car :)

This has a full service history with last full service by citroen done just a few months ago. It then also had a full MOT. Total milage 150 000 km

Thanks for taking the time so far.
white exec wrote:
13 Jan 2021, 11:02
The two pipes carrying hot coolant to the cabin heater matrix should both be hot, and with only a fairly small temperature difference between them. If one is cold, then there is no flow through the heater matrix, which suggests it is blocked.
At the age of the car, it is probably time to replace the matrix, unless a reverse-flush with a hosepipe can clear it. Nissens brand has a good reputation.

n0stra
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Re: 02 c5 blower not heating (mechanical)

Post by n0stra »

It's showing as normal. Right in the middle. Although I had a strange thing happened a few weeks back where the coolant temperature too high warning came suddenly in the dashboard lcd and the gauge showed in red. But popping the hood showed no such thing, it was cold outside and the car has only run for a few minutes. I checked the forums and saw that this was a error that several had experienced and as long as nothing else suggested thqt this was a fact, it would go away by it self.
Peter.N. wrote:
13 Jan 2021, 11:16
What is the water temperature reading?

Peter

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GiveMeABreak
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Re: 02 c5 blower not heating (mechanical)

Post by GiveMeABreak »

This is the heater Matrix on a C5 1.8 Petrol for example - it's similar to, but much smaller than your engine radiator, item (1):
image_2021-01-13_101824.png
These can become blocked over the years, resulting in reduced performance.

The pipes Chris is talking about are at 'A' & 'B'.

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Re: 02 c5 blower not heating (mechanical)

Post by n0stra »

As I have understood, doing anything that demands the removal of the dashboard is a nightmare to do yourself or costs more than the car to have professionals fix...

I would therefore firstly need to focus on everything else that might be the culprit.

Yes I know these are the pipes, they are the one I described in the TS. They are both hot, one very much so and the other a tiny bit less.
GiveMeABreak wrote:
13 Jan 2021, 11:23
This is the heater Matrix on a C5 1.8 Petrol for example - it's similar to, but much smaller than your engine radiator, item (1):

Image

These can become blocked over the years, resulting in reduced performance.

The pipes Chris is talking about are at 'A' & 'B'.

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GiveMeABreak
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Re: 02 c5 blower not heating (mechanical)

Post by GiveMeABreak »

Unfortunately, replacing the Matrix if you have no success back-flushing it is a very involved job and usually requires the fascia / dash removing to get it out and replace.

Blockages can be caused where previous owners have used Rad Weld or similar products to try and stop leaks - and this can block the very thin channels contained in the matrix.

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Re: 02 c5 blower not heating (mechanical)

Post by n0stra »

All services, annually since it was new, had been done by citroen dealership and there I no mentioning of any repair to these items. The owner has done nothing himself, and old teacher with no interest and no clue when it comes to cars. He's been spending 1000 to 1500 £ in avarage every year in dealership services and parts, based on receipts.

Some people in a Facebook citroen c5 group suggested that there are some wires connecting the knob adjusting the heat level in the center console, and that they might loosen up or get out of shape. And suggested just removing the facia and manage to check and fix this. Have you ever heard about something like that?

How would you do a so called "back flushing" of the system?


GiveMeABreak wrote:
13 Jan 2021, 11:38
Unfortunately, replacing the Matrix if you have no success back-flushing it is a very involved job and usually requires the fascia / dash removing to get it out and replace.

Blockages can be caused where previous owners have used Rad Weld or similar products to try and stop leaks - and this can block the very thin channels contained in the matrix.

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GiveMeABreak
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Re: 02 c5 blower not heating (mechanical)

Post by GiveMeABreak »

Here's somebody replacing the Matrix on a C5 2003 for info:


Here's somebody flushing the matrix on their Audi as an example:

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Peter.N.
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Re: 02 c5 blower not heating (mechanical)

Post by Peter.N. »

If perchance it did boil it might just be air in the matrix.

Peter