can u run with out a thermostat??
10-08-06, 10:52 PM
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can u run with out a thermostat??
hey i was just wondering cuz my thermostat is stuck and the parts store in like a half hour away, can you run the car without a thermostat?
10-08-06, 11:03 PM
#2
Not a wise idea. If you run an without a TS then the hot coolant will circulate back down to the water pump and get fed back to the engine. The TS closes this passage when the engine gets to operating temp and opens to the the path to the radiator. I'll find a picture.
10-08-06, 11:07 PM
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Originally Posted by RX_T2
hey i was just wondering cuz my thermostat is stuck and the parts store in like a half hour away, can you run the car without a thermostat?
10-08-06, 11:09 PM
#4
If you look in there you will see the passage where the coolant flows when the engine is cold. With no TS, not enough coolant makes it to the radiator. Might be able to make it to a Mazda dealer to get a new one, but I would recommend that you don't drive it like that. Oh, only get an OEM TS from Mazda. Aftermarket ones won't close that passage like it should.
10-09-06, 12:32 AM
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I guess none of you guys saying it'll overheat have ever actually run without a thermostat...
A lack of thermostat will cause the engine to run cold, not hot. There is nothing restricting the flow through the radiator, so it's over-cooled. The amount of coolant going through the bypass is very small in comparison. You can get overheating at high loads without a thermostat because the coolant flows too fast for efficient cooling.
It's fine to do run live this for a while (days, weeks, months even), but you are using more gas than you should and engine wear is higher than normal.
A lack of thermostat will cause the engine to run cold, not hot. There is nothing restricting the flow through the radiator, so it's over-cooled. The amount of coolant going through the bypass is very small in comparison. You can get overheating at high loads without a thermostat because the coolant flows too fast for efficient cooling.
It's fine to do run live this for a while (days, weeks, months even), but you are using more gas than you should and engine wear is higher than normal.
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10-09-06, 03:48 AM
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Originally Posted by slpin
if you think running without a thermostat would make your car overheat...
then you must think running without a wastegate would make your car not boost...
then you must think running without a wastegate would make your car not boost...
Originally Posted by fossil_484
Oh, only get an OEM TS from Mazda. Aftermarket ones won't close that passage like it should.
10-09-06, 06:37 AM
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With the stat removed almost half the coolant flow bypasses the radiator.
If you have to run without a stat, you should block the bypass port shown in fossil484's picture.
If you have to run without a stat, you should block the bypass port shown in fossil484's picture.
10-09-06, 06:58 AM
#12
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I ran my 88 GXL w/o a thermostat for about 2 months... I didnt really notice any side effects except for it taking a really long time to heat up the engine... I drove like that until the motor blow an oil seal and started smoke screening the entire city whenever I took the car over 4k rpm... After that I did my first JC swap...
10-09-06, 08:16 AM
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Unless rotaries run coolant differently, the only problem you should have is not much heat from the heater and slightly worse milige. The T-stat holds the coolant in the engine until it warms up, then opens and allows it to run through the radiator. Taking it out will just let it run through the rad all the time, making it run cold all the time, except possibly in traffic or high rpm loads.
10-09-06, 09:36 AM
#16
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Originally Posted by RX_T2
hey i was just wondering cuz my thermostat is stuck and the parts store in like a half hour away, can you run the car without a thermostat?
The RX-7 uses a bypass thermostat system. As the thermostat opens, the bottom extends to cover a bypass hole in the water pump housing. If you remove the thermostat, the bypass hole will never be covered and a large amount of coolant will simply recirculate around the engine without entering the radiator. This can cause the car to overheat if you drive it hard.
For a half an hour, it will be fine though.
10-09-06, 11:31 AM
#17
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Originally Posted by Stanello
Order an OEM Mazda thermostat. It'll be fine to run without one until you get it. Just don't let the car overheat.
I'm gonna get flamed for this, but I put a stant one in as a quick fix at the time, and it never overheats, sits below 1/4 mark constantly.
10-09-06, 01:51 PM
#19
Bongolio
Yea and when you spend 1100 dollars on a rebuild 20$ for an OEM stat isnt bad considering youll never overheat becuase of it. I wont even take the chance with my new motor.
10-10-06, 07:07 AM
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Originally Posted by NZConvertible
Do you have any basis for that claim?
The exhaust hot coolant in the pump housing has two paths it can take.
One is the smaller bypass port with pump suction directly behind it.
The other is the larger, but longer & more convoluted path through the radiator.
So, if maybe 30-40% of the coolant bypasses the radiator, you can still drive on the flat, but passing trucks on an upgrade will probably run up the temperature.
10-10-06, 08:06 AM
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Originally Posted by Aaron Cake
The RX-7 uses a bypass thermostat system. As the thermostat opens, the bottom extends to cover a bypass hole in the water pump housing. If you remove the thermostat, the bypass hole will never be covered and a large amount of coolant will simply recirculate around the engine without entering the radiator. This can cause the car to overheat if you drive it hard.
For a half an hour, it will be fine though.
10-10-06, 08:22 AM
#25
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this wasnt the smartest idea, but i ran my previous rx7 without a thermostat for almost a year and it ran fine, then all the sudden it just started overheating