Got my multipla back from the garage yesterday. It was making a racket when you put you foot on the clutch. New clutch kit fitted.
Took it out for the first time this morning and it oveheated. Warning lights came on....messages appeared telling me to turn the engine off or else.
Engine was undoubtedly very hot indeed. The air from the heater was scorching and the block smelt hot. However the radiator was stone cold. Limped it back to the garage and a few hours later they come back and say the themostat has failed.
Fair enough I suppose....but with the thermostat failed, how come the internal heaters worked? Does the thermostat just block the flow to the radiator? I always thought the whole water system was effectivley in series, not two independent loops.
I always thought the whole water system was effectivley
Nope. It usually splits before the thermostat with a small pipe going to the header tank. That allows sufficient water flow to heat up the heater matrix.
Neil gurgled happily, sounding much like they were saying:
If it was all in one, then it'd take _forever_ to heat up, since the rad would be trying to cool it down whilst it was still cold - so that's why the 'stat cuts the rad off until a minimum temp (89degC on mine) is reached.
If the heater was also cut off by the 'stat, then you wouldn't have any heating at all until the 'stat opened. Not ideal for defrosting on a cold morning. Also - on a cold day, the 'stat will be opening and closing all the time, as the temp bobbles around the lower end of the normal range. Again - just when you don't want the heater to be least effective.
That's quite fair. It was nothing to do with the repair to your clutch or clutch bearing.
It might be best if you and others learn how the engine works, how the cooling system works and where the heater is connected. The thermostat controls the water flowing through the radiator by temperature. When the engine is started from cold the water will only circulate through the engine until a specific temperature is reached. It will then be allowed to flow through the radiator. A thermostat in a car has nothing to do with the heater matrix or flow and return pipes to it. You're getting confused with a home central heating system!
Yes it does and is an on/off switch to put it in simple terms, controlled by the temperature of the water.
It in series, but the thermostat is blocking the flow until a certain temperature is reached. The heater is connected BEFORE the thermostat, so opening and closing it has no effect on the water flowing through the heater matrix.
I had to explain this to a ford main dealership once and draw a simple diagram as they misdiagnosed a faulty/blocked heater matrix as a "broken thermostat" and stood scratching their heads for 2 days.
It's a simple misunderstanding and if people took a bit more time to learn and research, they would be more clued up. Don't forget there are people, possibly like you, that know of an existing problem before a car is taken for repair. Afterwards they complain about the other problems to try and get them fixed for free. Most of the time people doing such a thing haven't a clue about cars so their dishonesty shows.
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