OK so my old temp gauge on my ke55s hasnt been working at all - i replaced it with a VDO and new sensor etc etc as well as water pump and thermostat. My question is now that I can see everything is working, the VDO shows the car

heating up to about 100-110 and then suddenly dropping to 79 and staying stable all within say ten minutes max. I was quite alarmed when I saw the temp climbing so high - so basically, is the new thermostat faulty

or is this normal and I'm not used to having an accurate guage ?? any help would be great :) cheers ps my daily driver is a golf and it just goes to 80 and sits there - has never gone higher ....

Doesn't sound right, the coolant and water mixture in your engine boils at around 107 degrees C.

Edited July 9, 201115 yr by rianwest

but it is pressurised so its boiling point will be higher. Have you checked the accuracy of the guage????? Grap a kitchen thermometer, the one with the metal spike, and put it in the radiator before you start the car. Let it idle and keep checking if the two read the same.

OK so my old temp gauge on my ke55s hasnt been working at all - i replaced it with a VDO and new sensor etc etc as well as water pump and thermostat. My question is now that I can see everything is working, the VDO shows the car

heating up to about 100-110 and then suddenly dropping to 79 and staying stable all within say ten minutes max. I was quite alarmed when I saw the temp climbing so high - so basically, is the new thermostat faulty

or is this normal and I'm not used to having an accurate guage ?? any help would be great :) cheers ps my daily driver is a golf and it just goes to 80 and sits there - has never gone higher ....

 

my 5k with a BHG (exhaust gases leaking into coolant)

 

turn the heater on and check if it suddenly goes cold at 110?

 

my 4k atm gets up to 82 degrees and lives at that. only SOMETIMES it gets high as 86 before shooting down

hey thanks guys - ok so i took the radioator cap off and ran the car for about 15 mins - temp got up to 90 on my digital

thermometer - and coolant started to overflow the radiotor a bit so I turned the car off - the thermostat housing was too hot to

touch but i coudnt really see any coolant mooving around ... so I took the thermostat out and slowly boiled it up suspeneded

in a pot of water and could see that it was only opening (and even then not fully) at boiling point and was fully closed at 82 when it was meant to be openening. I relpaced the thermostat and hey presto - everything seems to operating as it should be :) :)

nice work.

 

with the water overflowing the radiator. thats just the water expanding, all good, just let it dribble out, you wont lose much.

 

fairly soon after that happens, the thermostat will open, and you will see coolant rushing past in your radiator.

 

then after a while it will stop again. This is the thermostat regulating the temperature. (if you wait long enough it will happen again and again)

 

next time wait for this to happen, then just top up the water that spilt out, that way there is also a very good chance you have gotten any air bubbles out of the system (just make sure you are parked up a hill, or flat, just not down a hill)

 

then once you have filled it up to the brim (with the engine still running), put the cap back on and your done. make sure your overflow bottle has some water in it, so when it cools down it draws fluid from that bottle.

Just to add, for reference.

 

Tectaloy gold will be at about 120 degrees before it pops the radiator cap (that's a 90kpa cap)

Yes well done, you used the correct procedure for testing a thermostat, unfortunately you did it after previously installing it.

 

They are known to be often faulty even from new so I reccomend testing them before they go in each time, even if it is new.

Yes well done, you used the correct procedure for testing a thermostat, unfortunately you did it after previously installing it.

 

They are known to be often faulty even from new so I reccomend testing them before they go in each time, even if it is new.

 

yeah i was kinda thinking about that when I was replacing the "new" faulty one - why does an integral part of the cooling system only cost me $8.95 - like how much are they made for

in china and how reliable is that 82 degree stamp on the housing ...?? so, yes I think i will be testing them from now on.