Morning all, quick question about the 100 series heater, iv recently noted although the cab gets warm after a while, even on the hottest setting the air seems to only blow warm and not hot, is this normal ? I did have coolent system flushed over the summer, I havent taken too much notice of it before. many thanks.
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Heater question
- Thread starter Spike
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maurerframewerks
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I have a KZJ78 and it’s the same issue. Where can we find instructions on the proper coolant bleeding procedure? Thx!
Check the heater valve is actually opening fully....on an 80 with climate control it's cable operated by a motor and mounted on the bulkhead just behind the engine in the engine bay...don't know where it is on a 100 though .
Is your thermostat stuck open ? does the temp gauge take a long time to get to normal zone ?
Why did you flush the coolant system ? just good maintenance or because you had an issue ? It could be flushing the system caused silt / rust to block the heater matrix ....
Don't 100s have some kind of engine belt driven heating thing to speed up heating on cold days ? maybe this is the issue ?
Is your thermostat stuck open ? does the temp gauge take a long time to get to normal zone ?
Why did you flush the coolant system ? just good maintenance or because you had an issue ? It could be flushing the system caused silt / rust to block the heater matrix ....
Don't 100s have some kind of engine belt driven heating thing to speed up heating on cold days ? maybe this is the issue ?
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Three known (to me) issues, in order of likelihood:
- The temp sensor for cabin temp is not in place, which often means that it has fallen back to the heat outlet under the dash, sensing heater temp instead of cabin temp. On a LHD, the sensor is at the drivers knee, behind a tiny grille in the sloping under-dash cover. Whenever there has been work done in or under the dash, this sensor has to be put back in place.
- There have been cases of a valve failure, also under the dash. You'll find forum threads on this, either here or on mud.
- You could get an air block in the coolant system. Supposedly it might help to place the car in a really steep uphill and make sure the engine is fully warmed up so that the thermostat opens, and having the heating on max. This could make the air move to the radiator top tank.
- The temp sensor for cabin temp is not in place, which often means that it has fallen back to the heat outlet under the dash, sensing heater temp instead of cabin temp. On a LHD, the sensor is at the drivers knee, behind a tiny grille in the sloping under-dash cover. Whenever there has been work done in or under the dash, this sensor has to be put back in place.
- There have been cases of a valve failure, also under the dash. You'll find forum threads on this, either here or on mud.
- You could get an air block in the coolant system. Supposedly it might help to place the car in a really steep uphill and make sure the engine is fully warmed up so that the thermostat opens, and having the heating on max. This could make the air move to the radiator top tank.
Morning all, thanks for your replies, new thermostat when I had coolant flushed and it was just maintenance, no issues, temp gauge reads dead center, thing is now I think about it I dont ever think it was ever that hot, I will try steep hill and see if I can move any air, cabin temp sensor sounds interesting, any idea where it would be in a RHD? many thanks
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Tractionman
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To make it easier at home, put the front end on ramps, unless you live on a steep hill.
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Here's a thread with a pic of the cabin temp sensor, and the pipe it is supposed to be attached to. You can see the black bracket in the cover where the sensor is supposed to click in.
forum.ih8mud.com
Looks like it is located in front of driver's left knee in a RHD. Mirror image of LHD.
Climate control problem. 99 lx470
I just got a 99 lx470. My climate control doesn't seem to work right. The ac will work if the temperature is set all the way down to cold. If the temperature is set one click up, it wants to put the heat all the way up and direct to to feet. It can be 100 degrees out. Does this sound like...
forum.ih8mud.com
So a quick update, found the sensor,(just below drivers knee under diff lock switch) all connected and not loose, all be it fairly dusty, gave it clean, no difference, is it possible the sensor is bad? Found steepest hill I could and sat for 5 minuets on hot and no difference, drove around for half an hour on the hot setting and as said before the cab was warm but not super hot as I would have thought it should be, she is going in for a service today, I will see if they have time to take a look, its the facelift climate control, not that should make any difference. Many thanks
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Not had to do it on the 81, but in the past I've disconnected the heater supply hoses, given a reverse flush with a hose and then filled with kettle descaler. Leave overnight and then another good reverse flush.Usually helped, but if matrix is a bit iffy, removing the scale can lead to leaks.
