P38A Temperature question

tarphenry · Jan 22, 2019

Yet another problem ,I cannot solve. Last week the car (2.5 derv) got hot, just into the red zone.My fault entirely. allowed car to cool and topped up with antifreeze mix.. found the leak almost instantly (top Hose r/h side. removed cleaned and re sealed. Since then the gauge is reading low ,never reaches the centre,where it used to be.The pipes when hot have a slight pressure in, but I can squash them both and the water in the header tank moves with the squashing. There is a dribble of water coming through the small overflow and the heater works fine. I can remove the header tank cap when hot( Carefully) and it does not throw out water there is no water in the oil. all seems good except the gauge reading low. Your thoughts would be appreciated. NB I have drained and refilled but no change

wammers · Jan 22, 2019

tarphenry said:
Yet another problem ,I cannot solve. Last week the car (2.5 derv) got hot, just into the red zone.My fault entirely. allowed car to cool and topped up with antifreeze mix.. found the leak almost instantly (top Hose r/h side. removed cleaned and re sealed. Since then the gauge is reading low ,never reaches the centre,where it used to be.The pipes when hot have a slight pressure in, but I can squash them both and the water in the header tank moves with the squashing. There is a dribble of water coming through the small overflow and the heater works fine. I can remove the header tank cap when hot( Carefully) and it does not throw out water there is no water in the oil. all seems good except the gauge reading low. Your thoughts would be appreciated. NB I have drained and refilled but no change

There is supposed to be pressure in the hoses when hot. Either you have a duff temp sensor ( the front one on the head) or the stat is stuck open, pretty unusual for a waxstat.

RangeRoller dt · Jan 22, 2019

You can check your thermostat in a pan of hot water on a wire. It should open at about 80•C I believe, and move freely as it cools. The sensor is cheap enough to replace, check wires/connector are clean and not snagged while you are there

tarphenry · Jan 22, 2019

The stat is opening and closing because on startup the air is cold then the stat opens and air temp increases. Will look for correct sensor no and replace,see if that helps

RangeRoller dt · Jan 22, 2019

It could be stuck open as Wammers said, though unlikely. Sensor - STC2299. The green one

RangeRoller dt · Jan 22, 2019

This is a Lucas £9 motor factor one. The LR one looks same @£33

tarphenry · Jan 22, 2019

Thanks ,I will try that first

Datatek · Jan 22, 2019

tarphenry said:
The stat is opening and closing because on startup the air is cold then the stat opens and air temp increases. Will look for correct sensor no and replace,see if that helps

I thought the heater circuit got hot before the stat opened. The air is bound the be cold with a cold engine

tarphenry · Jan 22, 2019

sorry,you are right, its the top of the rad warms when the stat opens

RangeRoller dt · Jan 22, 2019

Datatek said:
I thought the heater circuit got hot before the stat opened. The air is bound the be cold with a cold engine

With my stat missing, as you so kindly made me aware, the heaters inside warm up pretty quickly not long after setting off.

tarphenry said:
Thanks ,I will try that first

The sensor, even at top price, is 1/2 that of new stat and known to fault. It's quick and easy to whip your stat out and test it to SEE rather than presume before spending out. 1hose and few 10mm nuts. If I did it anyone can

RangeRoller dt · Feb 11, 2019

I took some pics when I did the stat it really is a twenty minute job even for me. Front plastic cover, wiring, pipe and housing is all.
Can't work out why she is drinking so much

Hardest part is refilling the system, which I think you are well practiced.

Hope this helps

P38A Temperature question

tarphenry

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wammers

No longer with us, RIP

RangeRoller dt

Well-Sprung Member

tarphenry

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RangeRoller dt

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RangeRoller dt

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tarphenry

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Datatek

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tarphenry

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RangeRoller dt

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RangeRoller dt

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