Hello

Today we've got a pretty cold November day in here (1 deg. Celsius) so I switched the temperature selector from cold to hot (max.) expecting to get some heat inside after the engine reaches operating temperature. But nothing much happened even after 2-3 minutes. I had to put the blower on full speed to get some decent heat.

I remember some 4-5 years ago the heat was unbearable at maximum speed of the blower.

So I am thinking the heat exchanger (core or matrix?) is not doing its job, although both in and out hoses are equally hot to touch.

What is your advice to pinpoint the cause?

I think first of all I'd flush the system uing radflush or similar.

Hello

Today we've got a pretty cold November day in here (1 deg. Celsius) so I switched the temperature selector from cold to hot (max.) expecting to get some heat inside after the engine reaches operating temperature. But nothing much happened even after 2-3 minutes. I had to put the blower on full speed to get some decent heat.

I remember some 4-5 years ago the heat was unbearable at maximum speed of the blower.

So I am thinking the heat exchanger (core or matrix?) is not doing its job, although both in and out hoses are equally hot to touch.

What is your advice to pinpoint the cause?

Funny you should say that, the heat from my car is roasting even up half way, have to drive with the window open as the temp runs slightly hot on engine otherwise, need to flush system out also i reckon, what do you think?

Hello

Today we've got ... pinpoint the cause?

Well, since the hoses are getting hot (I presume at the heater matrix ends) I think we can probably rule out easy stuff like a blocked matrix or an airlock. If I suspected either of those, I'd suggest bleeding the matrix before things like radflush though.

And that seems to leave a mechanical failure of the mixer controls preventing the mixer flaps getting to the full hot position I'm afraid.

Funny you should say that, the heat from my car is roasting even up half way, have to drive with the window open as the temp runs slightly hot on engine otherwise, need to flush system out also i reckon, what do you think?

This suggests that the radiator isn't working at full efficiency. I'd check:-

1. External cleanliness and damage to exchanger fins on the front of the matrix. You may have to remove a grille and/or ducts or trim to see this area clearly.
   
2. Operation of thermostat, but ISTR you fitted a new one recently?
   
3. Ok, if I've done (1) and (2), I'd go with flushing the system, and since I'm doing the radiator anyway, do the block as well.
   

Editted to remove petrol-specficic advice since OP has a diesel.

Edited 22 November, 201213 yr by KenONeill

This suggests that the radiator isn't working at full efficiency. I'd check:-

1. External cleanliness and damage to exchanger fins on the front of the matrix. You may have to remove a grille and/or ducts or trim to see this area clearly.
   
2. Operation of thermostat, but ISTR you fitted a new one recently?
   
3. Ok, if I've done (1) and (2), I'd go with flushing the system, and since I'm doing the radiator anyway, do the block as well.
   

Editted to remove petrol-specficic advice since OP has a diesel.

Thanks,

Havnt fitted new TS, how to check the operation of that?

Thanks,

Havnt fitted new TS, how to check the operation of that?

Sometimes it's blatently obvious when you open the housing. On the assumption that it isn't, you get a thermometer and a pan of water and make "thermostat soup".

Suspend the stat in the water, and heat. You're normally looking for it to be closed when cold, start opening at about 70C and be fully open around 90C. If it fails any of those, you need a new one.

Edited 22 November, 201213 yr by KenONeill

Thank you all for advice.

Here are more details about my cooling system:

- radiator is new, also the thermostat

- I flushed the system thoroughly 3 months ago before filling with new antifreeze solution

- the engine runs very smooth, no overheating, fairly rapid reaches 80-90 deg. C and stays there as it should

So everything points towards Ken's suggestion: flaps not working properly.

Question is, what should I remove and what should I check for that? Any photos for better understanding?

Funny you should say that, the heat from my car is roasting even up half way, have to drive with the window open as the temp runs slightly hot on engine otherwise, need to flush system out also i reckon, what do you think?

Try having the heat up in a pickup: same size matrix etc - half the space to heat. "Nice and toasty" doesn't do it justice ;)

This suggests that the radiator isn't working at full efficiency. I'd check:-

I think the heater matrix on Felicia is huge and transfers buckets of heat. All the ones I've been in seen to run a touch hot, i.e gauge beyond the normal mark on the gauge, but sitting in the middle of the gauge. Felicia is the only car I've seen with the normal mark off-centre.

I changed the rad on the truck and made sure the replacement was flushed right through and clean before fitting.....made no difference to the behaviour of the gauge. (It did not have a hole in it to let the water out on the M25 though)

Editted to remove petrol-specficic advice since OP has a diesel.

OP has a 1.3 petrol ;)

Question is, what should I remove and what should I check for that? Any photos for better understanding?

My first port of call would be the knobs on the centre console - Do they "feel" like they're connected to anything?

Yes, they are. I know they are cable operated and there is definitely some movement.

Another sign of operation is this: with heating zone knob on "towards face and windshield", central dashboard vents open, and blower on, when I switch the temperature knob from cold to hot, blower sound gets dampened, as if something is closed.

From what I've read, it looks you can't connect cables to partially open a flap. It is either connected and get full movement, or not connected and the knob is loose.

I am willing to tear apart the entire dashboard if necessary to solve this issue, but perhaps there is a less invasive method, that's why I need some advice for next step.

Edited 23 November, 201213 yr by adurer

On second thought, equally hot hoses coming in/out of heater matrix is not sufficient proof it's working at full capacity.

If internal pipes are let's say half coated with slime, hot water will not heat the fins properly, but get out unaffected.

So I'll clamp those 2 hoses prior disconnecting them, and I'll rinse the heck out of that heater back and forth with high pressure hot water. If that won't do, I'll go for the (diluted) caustic soda method for 15 minutes, then rinse and dry with compressed air..

you can take air box out with out removing the dash if that helps but i have to remove engine now if i needed to take mine out as i have a diffrent air box does you fan work on all speeds

Update

I took the heater box out, dismantled it and inspected the heater matrix.

I found 2 problems:

- the temperature regulating flaps were seized

- the heater matrix had lots of dirt, leaves, etc. in front, working at half capacity

Now I finally have good heat inside

The only annoying things were those elastic steel clamps that have the bad habit of flying into the twilight zone when removed.

I tweaked a lot an illustration that depicts the heating/ventilation system (see attached) for those who need a better understanding.

One thing still remains unknown to me: there is a floor duct that supposedly should heat the feet of back passengers. But where is the output of that duct??

Edited 27 November, 201213 yr by adurer

From the big ? marks, I think that duct is optional. From the positions of the cutouts, I'd expect it to exit about the back ends of the inboard front seat runners on a car that has it.

Edited 28 November, 201213 yr by KenONeill

The big red question marks were put by me to indicate I don't see on my car any output in those areas.

Every Felicia hatchback or estate has that duct. My car has it too. But I imagine there should be some kind of grille at rear passengers feet. I don't have any. Do you?

Where is hot air exiting from, front and rear seats, when you select heating zone to 'floor' ?

To complicate things more, on rear doors (where they meet rear fenders) there are 2 grilles...

I'm pretty sure that the cutout that doesn't have a tab in it is at the handbrake, and that duct sits over the floor hump when it's fitted.

Grilles in the doors usually indicate the positions for loudspeakers.

I'm pretty sure that the cutout that doesn't have a tab in it is at the handbrake, and that duct sits over the floor hump when it's fitted.

That was obvious. Problem is, 10 inches to rear the duct ends. So I rephrase my question: what is the point of mounting a duct from underneath the dashboard, all the way to rear passengers footwell, if there's no output through a grille??

Grilles in the doors usually indicate the positions for loudspeakers.

Ken, perhaps my English vocabulary is not rich enough, so I have attached a detail illustration (red oval). That is called a "ventilation grille". What is the purpose of a grille to ventilate the air inside rear doors... beats me.

That was obvious. Problem is, 10 inches to rear the duct ends. So I rephrase my question: what is the point of mounting a duct from underneath the dashboard, all the way to rear passengers footwell, if there's no output through a grille??

None. What I'm wondering is whether or not this rear heating duct was only installed and/or active rather than blanked off on high specification models. I think the top L&K spec may be market specific, but there are at least 3 factory trim levels without allowing for variations in specificatin with year.

Ken, perhaps my English vocabulary is not rich enough, so I have attached a detail illustration (red oval). That is called a "ventilation grille". What is the purpose of a grille to ventilate the air inside rear doors... beats me.

We were talking at cross purposes. I was thinking of grilles in the door cards which might be mistaken for ventilation grilles.

Part #29, in the door slam, is indeed a ventilation grille, but to let stale air back out of the car.

Thank you for clearing me up.

Now, let's hope somebody has heating for rear passengers' feet installed on his car and will post some photos.

Am sure I've seen the 'S' bend installed on the pickup. Will have a look on saturday when I'm back at work.

I tweaked a lot an illustration that depicts the heating/ventilation system (see attached) for those who need a better understanding.

One thing still remains unknown to me: there is a floor duct that supposedly should heat the feet of back passengers. But where is the output of that duct??

Could you please upload once again the illistrations related to the heating - ventilation system? They may help me with the heating problems of my pick up. Thank you