Hot toes (M-Series heating....in Summer !)

[Notanutter]

Now I know that M Series heaters are inclined to be a bit inadequate, but in the current high ambient temps I'm having difficulties keeping mine OFF ! Although the heater valve appears to be moving (i.e. the cable inner moves fore and aft when the temp slider is moved side to side), I'm getting oodles of hot air in the car: does anyone know what happens if you just disconnect the heater matrix and use a bypass pipe, I seem to recall reading there is a kind of non-return flow valve in the matrix and I don't want to bu@@er things when otherise I'm having no probs with the engine overheating etc.

[davidy]

Peter

Yes you can bypass the heater matrix, just use a short piece of pipe. I did this several times with no side effects. It does though act as a small radiator so you will get a slight reduction in cooling effeciency.

With weather like this I would ensure you are running a lower temp stat. The standard stat is 88degrees but there are 81 and 74 deg stats available. the 74 deg stat was recommended for the Granada when towing. This will mean that the whole system should run cooler.

One of the big problems with a M series car is that when they get really hot they take ages to cool down. The cars really need vents at the top of the bonnet and/or wings to let the hot air that gets trapped at the bulkhead cool down. (A cool air feed for the carb is also a good idea when temperatures get this hot. Because of this hot air at the bulkhead it really doesn't have anywhere to go so heatsoak into the cabin is inevitable.

I had an 'SE' vent cut into my bonnet and with one of Adrian's big radiators, twin Kenlowe fans and a 74deg stat my car never got hot. Even after 30mins stuck on the M25 going to Golden Mania in 1997 the temp gauge never went above 90deg and my (now wife) driving out Griff500 was going apopletic behind as her gauge just kept rising!

davidy

[Notanutter]

Many thanks - so it's off the the local car spares shop now and a few quid should get this sorted, plus new air filter etc.

[ATE399J]

Stupid question..... you have checked the other end of the cable - i.e. that it is actually turning off the supply to the heater matrix?

[Notanutter]

Ah yes, I did check that. I followed David's advice and apart from geting a somewhat blank look from the guy in the car spares shop when I asked for a 74degree thermostat (he of the IQ of a lettuce), all seems to be well and we now have 20 much cooler toes. "At my leisure" I'll take out the heater box/matrix and give it a good overhaul with a hammer.