CX series 2 heater

[Sam Skelton]

Hi all,

Dailying a CX22RS Safari at present - and even by CX standards I haven't got a heater so much as a noise machine. There is virtually no airflow from the vents even with the fan turned up.

I know the recirc flap is working because I can hear the motor moving it. I have hot air if I get air - but I need my hand ON the vent to feel it.

I want to increase flow - not to a level where I burn my face off, but to a level where I can demist relatively quickly and where I can warm the car up during winter.

Can anyone offer me any advice? I'm new to CX ownership (though not to the experience) so not entirely sure where to start or even if my aim is unrealistic!

Sam.

[GiveMeABreak]

I never got any real heat out of my CXs - all the heater tubing seemed to be made out of some sort of cardboard - which was so easily torn - which led to fumes getting sucked into the cabin. So it was either death by carbon monoxide or wrap up like the Michelin Man!

[Peter.N.]

There is (or was) a device designed specifically for the problem, I ran diesel CX's which are even worse. It was an air intake scoop that fitted over the grill on the bonnet to collect air and force it into the inlet duct, I have never actually seen one in real life but there was an XM in a film many years ago that had one.

It shouldn't be to difficult to fabricate one although it doesn't exactly enhance the appearance of the bonnet. It was triangular in section, the front being about 3-4" above the bonnet and the rear end at bonnet level.

It was the aerodynamic shape of the car that caused the problem coupled with a not exactly enthusiastic blower motor.

Peter

[GiveMeABreak]

Yes, I had one on the Prestige - unfortunately, the tubing / ducting was perforated in many places (and also where these went into the dash) so I only managed to patch up a few holes with tape and attach the ones that were half hanging off.

A sneezing ant generates more wind power than the CX heaters though as you say Peter.

[Peter.N.]

My last XM was only about 5 or 6 years old when I had it so it should have still been in fairly good nick but the heater was sill useless, OK if you were going on a long run though as they car was warm within half an hour.

Lovely cars though, mine were all DTR estates, the last being a turbo, terrific performance for the time, ran it for 7 years and about 160k, never driven a car like it - if you can stand hypothermia.

Peter

[white exec]

It ought to be possible to diagnose poor air flow, or poor blower performance, on the CX, I would think. First step would be to look at the blower itself, and check whether it is able to generate a good air flow. These rest is just ductwork and airflaps.

Could be air flow being strangled or blocked, or a detached/holed duct, or air leaving the blower and inadvertantly re-entering it, or even a badly placed air intake in a low-pressure zone (so it is fighting the blower).

A real challenge, crying out to be investigated!

[GiveMeABreak]

Yes - mine had ALL of the above Chris! But after patching and plugging - I put it down to a poor motor for such a big car - it should of been 5 times more powerful and although there was room for a pony in the back of the prestige, I always kept plenty of blankets in the car as it was a floating ice box in winter!

And woe betide a drop of oil falling onto the manifold - choke....

[white exec]

Good bit of info here, and some interesting photos attached (post #11)...
http://www.aussiefrogs.com/forum/citro% ... r-box.html.

If blower (posts refer to two types: early ones with a horizontally shafted motor, later ones vertical) is under-powered, there are lots on the market which might be able to replace it.

I've never been a CX owner, so this is all blind guesswork.

[Peter.N.]

I had three of them Chris and they were all pretty well useless - and I feel the cold.

The last one I had was an '85/'86 and I had it in the early '90's son not really old enough for the rubber seals to have perished

Peter

[white exec]

Have to be grateful, then, for XM heater/AC, which was designed to deliver any selected cabin temperature (15 to 30C) irrespective of exterior temp -50 to +50C. Maybe they took CX shortcomings to heart.

[Peter.N.]

Oh yes, certainly one of the better features of the XM, a brilliant heater, and a handbrake that worked for more than 5 minutes after you adjusted it - pity about the loss of the diravi steering and central steering knuckles which set the CX apart from any vehicle I had ever driven. I can forgive it the handbrake and almost the heater.

Peter

[wurlycorner]

I've had/have lots of CX's.
You can get good hot air out of them (too hot in summer ) but unfortunately air flow is just crap - nothing more to say about that really. It's a long time (years!) since I have investigated the system, but a few things I remember...

Re-circ won't draw in as much air as fresh (the hole size that the fan can draw 'stale' air in from the cabin, is smaller than the fresh inlet hole size).

The seals around the flaps inside the unit are made of foam and have long since degraded and disintegrated/fallen away, so that won't be helping air leaking off into routes you don't want it to take instead of ones that you do, so if you feel adventurous, trying to replace the seals should be helpful.
Thinking back to when I did this on one of mine, I stripped out the flap, rubbed the old foam off (literally it falls off and the only thing left is the glue that used to hold it on) and replaced it with some modern ccf cut to shape, glued on with evostick and wrapped around the edges with carpet tape. There may well be better ways of doing it, but that what I came up with at the time.

You may also find that the heater matrix/air-con evaporator inside the heater unit are clogged up with debris, which will also reduce air-flow.

[white exec]

Air-flow on 'recirc' is usually less than 'external fresh' because of the absence of forward-motion ram effect of the air.
Wonder if anyone ever found a replacement blower that fits, is more powerful, and with fins and rotation in the right direction?

[Bilkob]

I've been using my GTI Turbo a fair bit lately, and yes, the heating and ventilation is just dreadful. How on Earth did Citroen think they could sell this back in the day??!!
Secretly I quite like the fact that its so gallic shrug the shouldsrs crap but honestly.....
I do remember on a previous CX of mine that I spent A LONG time diligently sealing ALL the gaps and holes everywhere and I also ran some 2 1/2" trunking from behind the grill straight into the heater 'tower' and that really helped.
I adore my CX but often wonder how good would it be if a certain other nation had been responsible for final fitting and assembly........

[Peter.N.]

The CX was such a brilliant car that I forgave it the lack of a good heater - it did get warm eventually if you went far enough. My last one was a CX25 DTR Turbo Safari with the porous block which necessitated fitting a new head gasket every 15k and I did about 160k in it, that's a fair few head gaskets but they were so easy to change compared with modern motors that I even forgave it that.

Peter