Heater Output.

[Paul H and D]

I've owned a few Volvo's over the years & never had to run the heater flat out.(Not unless you want to Roast) :)

I'm having to on my 94 D24TIC do they run that much cooler than a D24T for instance or is it something else.

(me getting older, stuck thermostat/heater valve, blocked matrix etc?

Had the car about three weeks Its getting warm but not the heat output I would associate as normal from a volvo.

P.S. writing this I,ve remembered the previous owner commented on having a new radiator anybody think it might be an airlock?

[DLM48]

does it have A/C? i have noticed my 945 SE TDic with A/C well it has a mind of its own and there is lots of heat there but not like on a non A/C car where if you wind up the heat controls and the fan to high speed you get instantly toasted i guess it is all controlled by sensors rather than you having direct control.

regards

[niloc]

I would drop the coolant and run a hosepipe through the heater matrix pipes at the bulkhead - that is the most common fix for ineffective heaters. Run the water both directions until it comes clear. Make sure heater is set to hot first though...!

[DLM48]

I would drop the coolant and run a hosepipe through the heater matrix pipes at the bulkhead - that is the most common fix for ineffective heaters. Run the water both directions until it comes clear. Make sure heater is set to hot first though...!

this is NOT a heater matrix issue but a sensor or a control air mix 'issue' there is plenty of heat available - it is just that the ACC system 'appears' to be quite happy to let you have cold feet for sure there is enough heat to melt the glass windscreen but the ACC does not want to distribute that to your feet the car temperature feels OK it is just your feet feel cold - i cant find a way to get lots of really hot toasty feet air to my feet.

there is another thread running about this

http://www.volvoforums.org.uk/showthread.php?t=48223

I have a similar but differnt set of symptoms on my "new" 760 turbo with aircon. Aircon seems to do nothing yet (surprise!) but let's ignore that for the moment.

On way from Kent to Nottingham (nonstop) on Sat - hot feet, cold left knee and nothing seemed to make any difference. Adjusted temp on climate control, pointed the air distribution control on the dash to all the available positions, tried all the different fan speed settings (which resulted only in increse/decrease of amount of heated air reaching feet or screen).

No sign of regulated air output from the dash vents (yes, I did try the regulator controls for each by the side of each).

Cold air footwell vents shut.

Permanent hot air to screen, permanent hot air to feet, cold draught (or cold radiation) on left knee. Central console cold to touch by left knee. Dash surface hot above central air vents, and hot by screen air vents.

Coming south on Sunday, car rammed to the gills with stuff from daughter's flat (she was moving to London) including squashy bags in passenger footwell so vents down there having any effect -

Much the same - but if anything air hotter. Unable to keep hot air off face. Some (but not much) increase of heat by turning heat right up, running heater fan flat out, and directing (according to dash control) all air to feet. Best compromise was to turn everything flat out, point it as feet, and open driver's window a bit to get fresh air on face.

Stopped at Toddington. Thereafter everything really toasty, no cold draught or cold radiation, but no way to turn anything down. Central console not materially cold. Feet about 40 degrees! Driver's window open allowed me to breathe cold air.

Going through Highgate and Holloway (stop-start, mostly stop) I was reduced to having drivers window fully open, and with aircon allegedly on and temp dial set to fully cold I was only slightly too warm and left knee OK. But I could get a faint inflow of hot air through middle dash vents by turning heater fan up to 5 and opening the regualtor wheels and turning the climate control to 26!

After unloading daughter's stuff (up 10 flights of stairs, no lift, good job her boyfriend is a fitness freak) and stopping for a takeaway - no great control of functions of heater, but average temperature reasonable and no cold on knee.

Suggestions? Where is the temperature sensor(s) for the climate control? Is the control of air distribution mechanical? How could I be unable to send air where I wished? Is the air temperature control by air blending or water valve? Why do the dash vents do nothing?

Baffled.



regards

[niloc]

Sounds like a vac pipe off somewhere then stopping the flaps from functioning properly. Could be a flap stuck, or an air duct off somewhere.

When you turn the air flow control, can you hear flaps moving and the air distribution changing?

[DLM48]

All 940's use an air mix system. Non ACC ECC cars have one mechanical control the temperature selector is a bowden cable to operate the main air mix shutter valve. The ACC system has flaps controlled by vacuum operated actuators - the fan is controlled electronically as are the air mix valves there are four sensors control panel sensor - temperature sensor - inner sensor - outer sensor if you have ECC you have a solar sensor too on top of one of the dash top speakers (i wondered what that was) the inner sensor is above the gearbox (ACC) or in the interior light (ECC) The ECC system uses solenoids and stepper motors rather than vacuum valves. There is a recirculate control too with another shutter valve and vacuum actuator.

hope that helps but i cant say it has helped me understand that i cant have roasty toasty feet

regards

[DLM48]

I would drop the coolant and run a hosepipe through the heater matrix pipes at the bulkhead - that is the most common fix for ineffective heaters. Run the water both directions until it comes clear. Make sure heater is set to hot first though...!

i dont think there is a water valve so you would not need to set the heater to hot to flush the heater matrix

but like i said this is not a not enough heat from the heater issue it is a distribution problem.....

i will be going out in the car soon so i will check in a more detailed manner when i come back and the car is hot assuming it is not dark by then or too cold to play at being a car mechanic

regards

[DLM48]

Sounds like a vac pipe off somewhere then stopping the flaps from functioning properly. Could be a flap stuck, or an air duct off somewhere.

When you turn the air flow control, can you hear flaps moving and the air distribution changing?

i have the solar sensor so i have the ECC system - i think :-) so i have lectronics micro processor - solenoids - stepper motors - not vacuum valves so i dont think it is a hose off 'problem' that would be easy to find in fact you could probably hear the sucking as you operated the controls lectronics is so much more fun NOT!!!

[Paul H and D]

I've owned a few Volvo's over the years & never had to run the heater flat out.(Not unless you want to Roast) :)

I'm having to on my 94 D24TIC do they run that much cooler than a D24T for instance or is it something else.

(me getting older, stuck thermostat/heater valve, blocked matrix etc?

Had the car about three weeks Its getting warm but not the heat output I would associate as normal from a volvo.

P.S. writing this I,ve remembered the previous owner commented on having a new radiator anybody think it might be an airlock?

This latest vehicle 94 945 D24TIC SE auto with sunroof option Therefore no aircon or ACC!
Regards Paul.

[RoyMacDonald]

This latest vehicle 94 945 D24TIC SE auto with sunroof option Therefore no aircon or ACC!
Regards Paul.

Paul H & D can you just make sure you havn't knocked the footwell vent open on drivers of passenger side first. It used to happen to my side or the passenger side every so often and makes the car feel a lot colder so it would be helpful to eliminate that cause first.

Roy

[Paul H and D]

Probably a very good idea.
More or less forgotten about those had a 92 wentworth for about 5 yrs which hasn't got them!
ECU on the side panel.
If it's to do with petrol injection the Diesel might have vents, but the more I think about it, It's probably the ABS Control Unit.
Therefore the 90 model 740TD before the Wentworth didn't have them either.
The 94 D24TIC got ABS but I'll definately check, or I could end up with a red face :)
Regards & seasons Greetings Paul.