Zach is wrong about using a hotter thermostat. No point in having the water staying in the radiator getting cooler if it isn't flowing through the engine anyway. The idea of different temperatures is to control when the thermostat opens to start the heat transfer, due to differing transfer rates with external temperature.
Believe what you want. But when you overheat because you went with a cooler thermostat because to you an open thermostat will keep temps down, then by all means.
Okay let's refrain from arguing guys, now if I get a hotter rated one would this not have the same characteristics as having a thermostat stick altogether? It seems like if you start getting everything cycling and cooling earlier on it would stay cooler. Correct me if I'm wrong Zach.
I understand that the longer its in the radiator the more it can cool off, but the water in the heads etc. Will be getting that much hotter, anybody have some resources or tests done for cooler and hotter thermostats?
Dam, you got me by a good 25 years gbilski! Hahaha now what about this dual stage thermostat, is this where it opens at a certain temperature but close at a different one? Im not familiar with it...
The top hose being hot and the bottom hose being cold indicates a flow problem. Either a sticking thermostat (most common and most likely) blocked radiator, or the impeller has come off the water pump (noit common, but I have seen this before).
You should use a thermostat that is specific for your car, rather than just a generic one. I am not familiar with your exact car, but a lot of thermostat have two sealing surfaces, one to seal a passage in the block and one for the main water flow (The one that Diegomx listed is one of these). Some thermostats have two flow valves, one small one that opens early, and one larger one that opens later.
Since this is the 2g forum, don't go buy the expensive Mazda thermostat. It's the same thermostat as the cheap one from AutoZone. Both are made by MotoRad. Get one of the standard 190 or 195 degree one they have. Pull your old thermostat and run your car for a few minutes without one to verify that you have coolant flowing. Also check to make sure you don't have any bubbles forming in your coolant. This can be indicative of a blown headgasket or cracked head.
If you run a lower temp thermostat, the engine will run colder, end of convo.
It makes clear and perfect sense. The engine isnt able to reach a higher temp because cold coolant is coming into the engine more often. If you think the engine will overheat from a lower temp thermostat because the coolant doesnt have enough time to "absorb the heat" from the engine, this is wrong. If you think an engine will overheat from a thermostat that is stuck open, this is also wrong. Dont over complicate something that isnt.
Alright cool, ill take it out and see if everything is flowing as Zach said, and thanks for clearing that up gbilski, you guys are a huge help! Much appreciated!
If you run a lower temp thermostat, the engine will run colder, end of convo.
It makes clear and perfect sense. The engine isnt able to reach a higher temp because cold coolant is coming into the engine more often. If you think the engine will overheat from a lower temp thermostat because the coolant doesnt have enough time to "absorb the heat" from the engine, this is wrong. If you think an engine will overheat from a thermostat that is stuck open, this is also wrong. Dont over complicate something that isnt.
answer me this one question though. Once the coolant reaches its operating temp of 190 or degrees, what's to stop the coolant from getting hotter? I'm sure you know how heat convection works. You also know that a cold thermostat at 170 degrees will stay open, not closing to stop the flow of coolant so it has a chance to sit in the radiator to dissipate heat.
stop the flow of coolant so it has a chance to sit in the radiator to dissipate heat.
the coolant doesn't get hotter because the radiator is efficient enough that it can maintain temp. a working motor can only overheat if the rad is too small or its air flow is restricted
coolant in the motor WILL get hotter as you let the coolant stay in the rad longer; and it will increase in temp faster than the coolant in the rad lowers in temp. these conditions would not be able to maintain a steady temp. therefore its not how the cooling system works.
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