Running without a thermostat
Thread Starter
Intermediate
Joined: Jul 2000
Posts: 27
Likes: 0
From: Greensboro NC
Running without a thermostat
I have been running a hypertech 165 deg. termostat in my 00 vert A6 for years. On the Hwy at cruise the normal coolant temp would run between 185 and 195 with AC on. After a dyno tune (because of a hot idle problem) the coolant temp now climbs to 220+. The Fans are working and just changed the coolant (50/50 mix). I decided to remove the thermostat to make sure it was not the problem. Testing proved no change in running temp on hwy or city. After talking to the tuner he said it was running hot because I removed the Thermostat. Since there was no difference with or without I don't beleive that running no theremostat would cause the engine to run hotter. The thermostats main function is to bring the engine up to operating temperature as quickly as possible.
Any thoughts or comments re. thermostat in or out.
Any thoughts or comments re. thermostat in or out.
Drifting
Joined: Oct 2004
Posts: 1,345
Likes: 3
From: Mesa Arizona
Did you suck up a plastic bag or something??? Get under the front of the car and look up at the rad. to see if you have an unwanted object/objects up there. (You may have to jack the front up a bit to get a look.)
A tune wouldn't make the car run hotter unless... Did you have a previous tune and had the fans turn on early and this tune put them back to the stock settings???
A tune wouldn't make the car run hotter unless... Did you have a previous tune and had the fans turn on early and this tune put them back to the stock settings???
Thread Starter
Intermediate
Joined: Jul 2000
Posts: 27
Likes: 0
From: Greensboro NC
Originally Posted by bcseitz
Did you suck up a plastic bag or something??? Get under the front of the car and look up at the rad. to see if you have an unwanted object/objects up there. (You may have to jack the front up a bit to get a look.)
A tune wouldn't make the car run hotter unless... Did you have a previous tune and had the fans turn on early and this tune put them back to the stock settings???
A tune wouldn't make the car run hotter unless... Did you have a previous tune and had the fans turn on early and this tune put them back to the stock settings???
There was a previous tune and I will check temp when they come on but they were definately running fullspeed at idle and temp would not drop below 210.
Thread Starter
Intermediate
Joined: Jul 2000
Posts: 27
Likes: 0
From: Greensboro NC
Originally Posted by Flat Broke
I can understand how not running a thermostat may not
make it run cooler, but I can not see how it would make it run warmer.
make it run cooler, but I can not see how it would make it run warmer.
Pro
Joined: Jul 2006
Posts: 529
Likes: 1
From: Princeton Texas
Originally Posted by TWilson
Agree... BTW nice bi-plane is that a stearman or waco (can't se the upper alerons), yours?
Last edited by Flat Broke; Aug 4, 2006 at 10:35 PM.
Pro
Joined: May 2004
Posts: 669
Likes: 0
From: CA
The thermostat serves two purposes. The first is to decrease the time needed to bring the engine up to operating temperature. The second is to control the flow of coolent so it does not circulate to fast. It needs to move slowly enough through the radiator to remove the maximum amount of heat possible. Too fast and the engine will run hot, to slow and the engine will also run hot. I would leave it in and look elsewhere. It sounds like your engine is running too lean, or the computer has the spark too far advanced.
Burning Brakes
Joined: Jun 2006
Posts: 866
Likes: 0
From: Placerville Ca
Couple of points:
1. In the olden days... lol - a tune up with timing advanced would cause a car to run hotter.
2. I have always heard if you completely remove the thermo. then the flow of coolant is increased to the extent it doesn't have enough "hang time" in the radiator to cool before heading back into the engine. The thermo housing itself still provides restriction even with the valve open.
3. Runing with the thermo out is dumping cold water constantly into your engine while you are trying to warm it on start up. That's also a no-no.
Bottom line is you either have a restriction in your flow like:
A. Crap in your radiator
B. Something blocking the air hitting your rad.
c. Bad thermo.
or, it's the tune, or it's the fact that your flow is too fast to cool, or you've blown a head gasket or cracked your head.
That's about it...
Edit: Damn by the time I typed up all this crap, Mike stole my thunder! Damn you Mike, damn you all to hell (borrowed that from Planet of the Apes).
1. In the olden days... lol - a tune up with timing advanced would cause a car to run hotter.
2. I have always heard if you completely remove the thermo. then the flow of coolant is increased to the extent it doesn't have enough "hang time" in the radiator to cool before heading back into the engine. The thermo housing itself still provides restriction even with the valve open.
3. Runing with the thermo out is dumping cold water constantly into your engine while you are trying to warm it on start up. That's also a no-no.
Bottom line is you either have a restriction in your flow like:
A. Crap in your radiator
B. Something blocking the air hitting your rad.
c. Bad thermo.
or, it's the tune, or it's the fact that your flow is too fast to cool, or you've blown a head gasket or cracked your head.
That's about it...
Edit: Damn by the time I typed up all this crap, Mike stole my thunder! Damn you Mike, damn you all to hell (borrowed that from Planet of the Apes).
Last edited by SultansDiamond; Aug 4, 2006 at 11:03 PM.
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Le Mans Master
Joined: Aug 2002
Posts: 8,222
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From: Norfolk VA
thermostats slow the coolant down so it stays in the radiator longer, w/o out it, the water goes through the radiator to fast to be cooled so it runs hotter.
Also, the thermostat has nothing to do with how hot the car runs (assuming that it opens when it is supposed to), thermostats just control the minimum operating temp.
check to make sure your radiator is clean
Also, the thermostat has nothing to do with how hot the car runs (assuming that it opens when it is supposed to), thermostats just control the minimum operating temp.
check to make sure your radiator is clean
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 764
Originally Posted by Lancer033
thermostats slow the coolant down so it stays in the radiator longer, w/o out it, the water goes through the radiator to fast to be cooled so it runs hotter.
Also, the thermostat has nothing to do with how hot the car runs (assuming that it opens when it is supposed to), thermostats just control the minimum operating temp.
check to make sure your radiator is clean
Also, the thermostat has nothing to do with how hot the car runs (assuming that it opens when it is supposed to), thermostats just control the minimum operating temp.
check to make sure your radiator is clean
Le Mans Master
Joined: Feb 2006
Posts: 5,267
Likes: 40
From: Phoenix AZ
I just installed a Honker the other day, and had to remove the shroud.
I removed a dead bird, sticks, feathers, approx. 1500 small pebbles, hair, leaves, etc. Dropped my temps by 15 degrees in town driving.
I removed a dead bird, sticks, feathers, approx. 1500 small pebbles, hair, leaves, etc. Dropped my temps by 15 degrees in town driving.
Drifting
Joined: Oct 2004
Posts: 1,345
Likes: 3
From: Mesa Arizona
Originally Posted by gpracer1
I just installed a Honker the other day, and had to remove the shroud.
I removed a dead bird, sticks, feathers, approx. 1500 small pebbles, hair, leaves, etc. Dropped my temps by 15 degrees in town driving.
I removed a dead bird, sticks, feathers, approx. 1500 small pebbles, hair, leaves, etc. Dropped my temps by 15 degrees in town driving.
