My reliant K is is constantly over-heating even after 10 minutes of running time. Is that a thermostat problem?

the cooling system needs service .
get some?
do you want 25 guesses?
or all tests to find it.? and tools and how to use those tools.
never run sans STAT it can cause big turbulent problems at the pump impeller. (an new one is what we do, for sure 10 years old is its engineered life span so is DUE.


https://www.youtube.com/watch?v=-EpwWtHzpHw

1,2,3
new cap , new STAT
step 3 is find leaks/ on ground or on passengers toes?<heater core.
and lots more sorry not typing them again and did so way too many times here.
the hot coolant is under 15psi, and if there are any leaks
this magical fact (physics) allow you to find leaks easy, .
parked hood up. leaks. find them. even take your time and look hard.

If it runs constantly from cold startup... its electrical... see an auto electrician. If it starts up and runs constantly after it heats up then it can be a faulty thermostat (even new can be faulty) Tip (Put it in boiling water before installed and see if it opens) Also some non genuine water pumps will not cool the car properly.

No It is there for a purpose and the problem that makes you consider the removal of the thermostat should be fixed . It is there to bring the coolant to correct operating temperature as quickly as possible and then to regulate the flow through the radiator to maintain a constant temperature. The easiest check for a thermostat problem is to start the engine cold and let idle for around 10 minutes Place your hand on the top radiator hose and if the thermostat is ok you will feel the hot water start to flow through the hose. If you have the radiator cap off you will feel the water heat up and you may see the water start to flow as well.. Over heating problems can come from blocked or partially blocked radiator cores, leaking head gaskets or cracked head, thermostat, old soft hoses, timing , air/fuel mixture, blocked exhaust, overload /over speed , wrong gear resulting in excessive rpm's, coolant fan not working, viscous fan hub not driving fan, loose fan belt, blocked fins of the radiator( plastic-grass-mud)

Ok, here is my take on your problem. As you may already know, it takes a car a few min. to actually warm up to operating temp. When the coolent reaches operating temp. the thermostat opens to circulate the coolent in the radiator. Now, as your drive, the air pushing against your car will actually blow some air through your heating system ducts and into the passenger compartment. Is it possible that your blower fan isn't working? Because while you are stopped, there would be no air forcing its way through your ducts, thus no heat. As your drive, your car gets up to operating temp, heats up, and the air pressure as your drive will blow some heat out into the passenger compartment? On a side note, if your thermostat is stuck in the open position, it would take it forever to warm up since it is circulating ALL the coolent even tho it isn't at operating temp. A thermostat stuck open will take 30 min or more before you actually feel any warmth, if at all in the winter.. your thermostat opens and closes constantly as the engine is running to keep it at its normal temp, usually around 160-180 degrees. If you live where it gets really cold, a thermostat stuck open likely will never get warm. If your blower motor works, and your engine don't overheat, im 98% sure its your thermostat.

With these types of issues it is always best to start by flushing out the cooling system and replacing the thermostat. If you get no heat out the vents, that points towards a clogged heater core which usually will need to be replaced.

Are you sure that the spring side of the thermostat is toured the engine/ look for a bleeder near the top highest spot in a line or hose that may be able to release the air it may even be near the water pump side.on some water pumps for the ford's the pumps will bolt on and look almost the same but the fins on the impeller are the opposite.clock wise instead of counter clock wise or vice vars. you my wont to check with your parts supply store to see if that is possible.hope this helps give you some ideas.feel free to ask again if you would like any further assistance.thank you for asking fixya . Have a Grate Day

7 degrees before top dead center if you got the mitsubishi 2.6 and either 10 or 12 btdc on the 2.2 double check you vehicle manual to be exact

Possible cause ;
1. Water pump
2. Thermostat
3. Bad head gasket.
4. Low coolant level.
Try to replace thermostat first , this way you illuminate thermostat and coolant level , you'll have to ad coolant after replacement and purge system.

There is a fan relay in the fuse box in the engine compartment. Usually that is the reason why it won't turn off. It fuses in the on position. If you have the manual it will say which one is the fan relay. just pull it out and get a new one. They are not expensive.

Hope this helps

follow the top radiator hose to the top part of the motor and youll fine the thermostat there the housing is held on by 2 bolts