Technical Heater problems in Uno

[Thunderer]

The heating in my Uno is average at best. During the freezing period when it was below -10 C, the heater would just enable a little milder temperature, that combined with the body heat of the passengers made driving in it bareable, but no way would you be comfortable driving without a coat on. When I go onto an open road the story is even worse. Even though the engine is much hotter the heater would release air only minutely milder than the outside temerature. I'd have to slow down to 60 to 80 km/h to feel the difference.

When I set the heater on the control panel to blow through the outlets on the panel, there is actually no difference in the tempereature what so ever. I only feel a difference when the air is set to blow through the windshield outlets and a milder temeperature when set to blow at the feet (I hope I am making myself understood here).

Is this normal for an Uno or should I try to repair it myself (not a mechanic though). Is there a simple push the button trick somewhere under the bonet or a duct tape solutio, or should I take it to a mechanic to fix it?

 

[Peterg]

The air vents on the dashboard only provide fresh air from the outside so do not give warm air, unless of course it is warm outside.
Does your engine temperature get to its normal running ie 90 degrees?
If it does and your not blowing out warm air you may have a blocked heater matrix.
The unos even when working properly do not give off a lot of heat, mine blows warm but I would never call it hot air.
Keep the fan speed low as it tends to give off warmer air as it has more time to get heated.
Do a search here on heater matrix, apparently it is a pain to fix as access to it is restricted.
You may get away with just flushing it if that is the cause of your problem.
Another cheap fix as you mentioned is putting some cardboard on the front grill to restrict cold air cooling the radiator.
Obviously keep an eye on your temperature guage.
Good luck
Pete

 

[Peterg]

just noticed you should put this in the technical area I am sure our friendly moderator Louie Bee will do it for you.
pete

 

[Chas Uno]

I'll add a little to the advice from PeterG.

Check the operating temperature of the engine. The gauge should go up to 70 degrees even in cold weather, and the fan should cut in at 90 degrees in hot weather. If your car is struggling to get the temperature gauge up to 70 degrees even after a few miles of driving, your thermostat is probably shot and making the engine run cold. Only option is to change it!

While you're at it, it is a good idea to back flush the engine and put in new coolant/ antifreeze. I did a thread on here about doing this, so have a search as I don't know how to find it! Or maybe Louie can find it and point you to it?

Also check the two pipes running into the bulkhead behind the engine. Make sure the heater is switched to 'hot', and check the temperature of both pipes. If one is hot and the other is cold, your heater matrix is blocked or the heater valve is seized. If both are hot but you still don't get much heat from the heater, then the flaps in the airbox might be jammed closed.

Peterg is also right about the cold air from the face/ centre console vents. They are fresh air vents only, you only get heat in the footwells and for the screen.

On the bright side, spring is round the corner so you don't have to worry so much about being cold when driving

 

[Thunderer]

Thanks Peterg and 1986Uno.

... and sorry for not posting in the correct category.

 

[M@nticore]

on the uno there is a valve conected to the selector cable for the heater, maybe it's not opening the valve all the way or the valve is blocked.

 

[alexGS]

Just make sure, before going any further, that you have the white-labelled lever fully to the right. If that lever is to the left, there is no airflow through the heater unit. Of course, the red-labelled lever has to be fully to the right as well!

I agree with M@nticore. Look down at the right side of the heater - you see either a white valve or a black valve, with one of the heater hoses and a cable connected to it.

If the body of the valve is heart-shaped (most of the black ones are) then that is a later-design valve than the rectangular-shaped design (most of the white ones). The later design has a rotating plate with a hole in it. The earlier design has a sliding plate instead - which tends to jam, even if the operating lever appears to move correctly!

It's best to take the valve off if in doubt (put a plastic bowl in the footwell, and loosen the valve - coolant will come out of both the hose/valve and the heater radiator.) Inspect it for opening/closing and replace if there is any hesitation. Second-hand will be OK, preferably the heart-shaped design.

After replacing the valve, fill the cooling system carefully - remembering to undo the tap on the heater hoses where they exit the engine compartment. If you don't have the tap, then leave the heater turned on full and run the engine with the radiator cap removed, making sure that you continue to top-up the level as the engine warms up (and again after it has cooled down).

It IS worth the trouble - assuming that your thermostat is good (I agree with Chas too!) then the heater should have plenty of output - it's only a small car! If you have all the fresh air vents turned off and the fan on, it should be quite warm within a few kilometres. I have tested mine in the snow at our ski-fields, so I know that even at 0-degrees outside, the Uno heater can work well. But this is with the engine at 90 degrees, remember...

I have the opposite problem, as it turns out My Uno Turbo's heater is partially-on even with the lever 'off', so in the summer (rapidly running out, though) it's a bit hot for comfort! Have to open the nice, quiet and reliable electric window (but that's a whole other story, as they say)...

-Alex

 

[Barney vd Merwe]

Do a search here on heater matrix, apparently it is a pain to fix as access to it is restricted.
Pete

And so it is evident the the matrix is leaking, water squirting into the passenger foot well at a rapid rate. Time to stick my head in there - remove the trim and part of the fascia and check out the water damage. Alternatively I could plug the pipes in the engine bay connected through the bulkhead....and fix the matrix another day. I went through the same scenario 20 years ago when the heater matrix "went" on the Renault 9 during peak hour traffic in the middle of summer. The pipe burst and all the coolant/water was inside the car in stead of inside the engine and the radiator. Eventually the car overheated and major engine damage was inevitable....