Thermostat gone?

Fast Guy

Moderators
Staff member
I think my thermostat may have gone.

Engine is getting hot, (but gauge reads normal:roll: ) heater is blowing very hot, oil temp is rising alot faster than normal, say upto 90 in about 5mins.
Rad top hose is very hot, bottom hose is cold, radiator is pretty much stone cold.

Does that sound like the thermostat's packed in? (if not it'll be the water pump)
 

Lionel

Member
carl take it out and test it over a kettle to see if it opens if it dus u can rule it out form being damaged
 

Fast Guy

Moderators
Staff member
If it does open, I guess that only leaves the water pump. I thought they always leaked when they died. This one hasn't.


Edited to add, if it was the water pump, the heater wouldn't get hot so quick would it?, thermostat blocks the flow through the radiator, but the coolant can still circulate around the pipes on the back of the engine if the water pump is pumping it.
 
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Fast Guy

Moderators
Staff member
Water level is fine. No signs of any leaks. Where are the core plugs? back of the engine?
 

MarkTurbo

Well-Known Member
Fast Guy said:
If it does open, I guess that only leaves the water pump. I thought they always leaked when they died
Like mine is at the moment :lol: :doh:

Thermostat not opening gets my vote ;-)
 

Braveheart

New Member
Fast Guy said:
Can't think of anything that would completely block the rad off the top of my head.
The water is not circulating by the sounds of your decription. Termostat, Pump, blockage or no water!
 

stumo

Active Member
thermostat or blocked rad gets my vote.....thermostat being favorite.

the only way a waterpump can fail to pump water (even if it's leaking) is if the vanes have fallen off (or rusted away) and i can't remember that ever happening.
 

Fast Guy

Moderators
Staff member
Braveheart said:
The water is not circulating by the sounds of your decription.
The heater is blowing very hot air, but the rad (just as far away) is stone cold. All the pipes on the back are like a seperate system when the thermostat is shut, so I'm getting the impression, for the heater to blow hot air, the water is circulating though it.
 

jameswrx2

Member
stumo said:
thermostat or blocked rad gets my vote.....thermostat being favorite.

the only way a waterpump can fail to pump water (even if it's leaking) is if the vanes have fallen off (or rusted away) and i can't remember that ever happening.

This always bugs me when people say about water pumps 'failing' what do they mean. I think along the same lines as you there, what can go wrong with them apart from the bearing? (which isn't going to stop the water being pumped, it'll just make noise) But I keep reading about a hole that leaks water when 'the water pump dies' :noidea:
 

Braveheart

New Member
The heater rad gets hot bofore the thermostat even opens... that's one of the reasons for a main thermostat. Gets heat into the cab quickly to defrost screen and heat to tootsies....
 

stumo

Active Member
jameswrx2 said:
This always bugs me when people say about water pumps 'failing' what do they mean. I think along the same lines as you there, what can go wrong with them apart from the bearing? (which isn't going to stop the water being pumped, it'll just make noise) But I keep reading about a hole that leaks water when 'the water pump dies' :noidea:
They mean the seals on the pump failing. When that happens the water comes out of a hole on the front of the pump.
 
J

jpward

Guest
Easy way to check is to remove the thermostat from housing and refit housing and top up with water and run to quick test.

If it is no different i would then try the rad as the water being hot and making its way to the matrix would tell me the pump is fine and theres no air in the system so also helps to rule out burst hoses etc.
 

neil240z

Member
the water pump is fine, if the heater matrix is filling the car with hot air then the water pump is working, very good chance the thermostat is buggered and blocking the return flow of water to the rad, or rad is blocked. wont be core plugs.
keep us posted.

regards

Neil
 
J

jpward

Guest
neil240z said:
the water pump is fine, if the heater matrix is filling the car with hot air then the water pump is working, very good chance the thermostat is buggered and blocking the return flow of water to the rad, or rad is blocked. wont be core plugs.
keep us posted.

regards

Neil
Think you are a bit mixed up there! ;-)
 

CanadianR

Member
Well I know that if it is stuck OPEN that your heater will not blow any heat for a long time after initial startup. I had the unfortunate situation happen to me in the middle of a Canadian Winter. :lol:
 

Fast Guy

Moderators
Staff member
Well, the thermostat has been in boiling water for a couple of mins and nothing has happened.

jpward said:
neil240z said:
and blocking the return flow of water to the rad

regards

Neil
Think you are a bit mixed up there! ;-)
You mean that bit? It flows from the rad into the thermostat doesn't it? (although it's still correct in a round about way as there will be no flow through the rad at all if the stat is shut)
 
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