No Thermostat ?

[QuantumJo]

I can't give you a textbook answer, but only what works for me. I generally run a 160 degree thermostat in the winter & sometimes NO thermostat at all in the summer. Realize it regularly hits 100-110 here for weeks at a time in June through August. I have done this on 318's, Ford 4 cyl, Jeep 4.0 HO's, Toyota 22r's, 440's, all without issue.....Also these are all seasoned engines. Running a engine COLD does screw up emissions & increase cylinder wear, but I can't afford & wouldn't own a new vehicle/engine anyways. My old 150k mile engines are wore to begin with. I run the dickens out of them. I'd rather have "potential" increased wear from running them cold, than the more likely issue of burning them up from overheating.

I don't think you would go wrong with a 160 degree thermostat, even year round.

Bucky

I would think that an engine would run cooler if the coolant had some time
to spend in the radiator before getting pumped right back to the block.

.

[Kevin Mienke]

I understand what you are saying and it makes perfect sense, but the fact is, engines run cold without the t-stat.

I had overheating problems caused by a thermostat stuck closed when I was nowhere near a parts store. My only option was to run without one. I ran cool for about a 100-mile drive from North Platte, Ne. to Kearney, Ne. where I stopped at a parts store and got a new one.

Running without a t-stat for extended periods is not good because the engine runs too cool. If the engine runs too cool, the fuel mixture won't burn completely. Eventually the unburned fuel ends up in the crankcase.

You want to keep the cold stuff in the radiator when you are warming the engine up, thus circulating the hot stuff in the block for an efficient warm-up. When the anti-freeze has reached 180, it is important that the thermostat opens and circulates through the radiator or you will overheat the engine.

I understand the theory behind what Bucky is saying, and I know a lot of people that run without t-stats in older engines, but personally I would never run without a proper thermostat unless I was in dire straits as I was on that day Nebraska.

[Aaron S]

I have lived in Texas my whole life and worked on cars and trucks here for most of it. I am not sure about newer trucks, but with anything built before fuel injection and electric fans it is quite common to remove the thermostat during the summers here, people have been doing it for decades. Regardless of make or model they will run 10-12 degrees cooler without the thermostat.

While a thermostat does indeed hold the water in the radiator longer, it also keeps it in the block longer allowing more heat to build up, especially in the heads. Holding the hotter water in the radiator longer does not negate the effect of getting the water (and the whole engine) hotter in the first place, especially when one considers the cooling properties of the 100+ degree air blowing through the radiator. The idea of running cooler without a thermostat may seem counterintuitive to some, but around here it is a widely believed fact.

Keep in mind that the primary function of a thermostat is to make an engine build heat faster, not to dissapate it.

[712edf]

To even further show my insanity, on a 79 w200 318 club cab I once had, not only did I pull the t-stat, I also used a 12 gal air compressor tank (in cab) inline with my heater hoses. This gave me approximately 16 gallons of coolant capacity. I had a shut off valve that I could stop/reduce coolant from flowing through the tank, same as turning off the valve for the heater core.....This truck ran excellant. I imagine the coolant temperature to be under 140. Just about right in my book for this old rig. No vapor lock, no dragging starters, no headaches whatsoever. Mileage might have suffered from running cold, but it seemed to improve from the winter driving cause I got in & went. I wasn't afraid to venture out in this extreme heat we have around here.

Understand there is a period of time around here when the air temperature doesn't ever get below 80-85 for weeks sometimes.

Yes it was very expensive when I first added my antifreeze!

The reason I recommend 160 thermostat is this. A thermostat (single stage) only sets the minimum temperature that a engine will run at. Once they are OPEN, the engine can't tell if its 160, 180, 195 whatever. All OPEN thermostats are basically the same. You can overheat an engine with a 160 thermostat just the same as with a 180 or 195, it just takes longer to get there. Newer vehicles are designed to run hotter, do to emissions & such. As long as its not boiling, theoretically you could go way on up there. But I don't see the point in pushing my old tired machines. I am not a teenager anymore, I don't like playing or working in the direct heat. I don't figure my vehicle does either, so the thermostats will be coming out in a few weeks in my fleet.

Bucky

[Gordon Maney]

A thermostat, when working properly, has two purposes. One is to bring the engine up to operating temperature quickly, and the other is to determine a normal operating temperature. The cooling system's ability to actually determine and control the operating system effectively depends on all critical factors to be correct. Meaning, filled with clean coolant, radiator fins and tubes clean, water pump and fan working correctly, and thermostat working correctly.

If you are low on coolant, have blocked coolant flow, blocked air flow, a poorly calibrated or inoperative thermostat, things will go wrong and the engine will overheat.

I have run engines with no thermostat and with disabled thermostats. There are engines that will overheat with no thermostat due to the fact that the coolant runs through the radiator too fast, resulting in the coolant not being able to dump sufficient heat.

My typical answer to a defective, or thought to be defective, thermostat, is to remove the valve from the thermostat, installing only that large, sheet metal disc that remains. That actually allows more water flow than if the thermostat was open. Over the years, in certain suspect vehicles, I have carried a disabled thermostat in the toolbox or glove compartment.

Several other measures you can employ if you feel you are running hot. Run the heater on full fan and full heat. If you have an engine that you determine is running too hot and have chosen to stop, yet want to cool it more before a shutdown, use a spray bottle of water and mist it on the radiator fins. Boiling that water off the radiator tubes and fins is a very effective heat removing method. Do NOT simply pour water from a bucket on your radiator or engine assembly.

[Kevin Mienke]

I don't necessarily disagree with anything that's been said, especially if the vehicle is a "suspect vehicle" as Gordon said. However....

I’m still gonna be a bit of a stick in the mud on this one. Typically, if a guy is having overheating problems and takes the thermostat out to “fix” it, he is likely masking a different problem such as plugged cores, rotted distribution tube, timing out of adjustment, bad engine oil, worn fan belt, or any one of a number of other things that make for cooling problems. It would be best if he correctly diagnosed the source of the problem, fixed it, and then used the proper thermostat that will open and close as he and his engine would like it to. This would ensure that your engine is running hot enough to burn off the condensation in the crankcase and burn gas efficiently.

Thermostats are, without a doubt, the most unfairly maligned components in the cooling system. For the most part, they perform faithfully and reliably, yet they have gained the reputation as something that needs constant attention. People change them out in the summer and again in the winter and then again the next summer. Seriously, just put the thermostat in that the service manual calls for and let the darn thing do its job.

We drive in 110 degree heat here as well as below zero. My engines have run well in these extreme weather conditions for all of my life.

I like for my engine to get to operating temperature quickly and then stay there. The best way to do this is exactly the way the engineers planned it out…with a thermostat.

If you guys want to hold me down and hit me with a stick the next time you see me, that’s ok. But I like the idea of keeping a good thermostat in all of my engines.

Please don’t be put off by what I’m saying. Just hit me with the stick. :-)

[Charles Talbert]

I don't necessarily disagree with anything that's been said, especially if the vehicle is a "suspect vehicle" as Gordon said. However....

I’m still gonna be a bit of a stick in the mud on this one. Typically, if a guy is having overheating problems and takes the thermostat out to “fix” it, he is likely masking a different problem such as plugged cores, rotted distribution tube, timing out of adjustment, bad engine oil, worn fan belt, or any one of a number of other things that make for cooling problems. It would be best if he correctly diagnosed the source of the problem, fixed it, and then used the proper thermostat that will open and close as he and his engine would like it to. This would ensure that your engine is running hot enough to burn off the condensation in the crankcase and burn gas efficiently.

Thermostats are, without a doubt, the most unfairly maligned components in the cooling system. For the most part, they perform faithfully and reliably, yet they have gained the reputation as something that needs constant attention. People change them out in the summer and again in the winter and then again the next summer. Seriously, just put the thermostat in that the service manual calls for and let the darn thing do its job.

We drive in 110 degree heat here as well as below zero. My engines have run well in these extreme weather conditions for all of my life.

I like for my engine to get to operating temperature quickly and then stay there. The best way to do this is exactly the way the engineers planned it out…with a thermostat.

If you guys want to hold me down and hit me with a stick the next time you see me, that’s ok. But I like the idea of keeping a good thermostat in all of my engines.

Please don’t be put off by what I’m saying. Just hit me with the stick. :-)

I'll have to stand with Kevin on this issue. Too hot, Too cold, or not warming up to operating temp promptly and holding there, neither is good, and can certainly cause some really undesirable issues. I've seen engines without t'stats installed heat up really warm on hard pulls up hill, only to cool so quickly going down the other side that heads were cracked. This was a real factor on older 2 valve Detroit Diesel engines. It's there for a purpose, just keep that in mind.

[Gordon Maney]

Understand, I am not advocating running without a thermostat or even a disabled one. I have done that to get home, or move a vehicle to a repair location.

[Kevin Mienke]

Understand, I am not advocating running without a thermostat or even a disabled one. I have done that to get home, or move a vehicle to a repair location.

With all of the stitches and pins and metal plates in my body, I understand making the most of disabled parts.

In my heart of hearts I knew you supported a complete cooling system, but for a fleeting moment I thought maybe, just maybe, I could finally snatch the pebble from your hand.

[Gordon Maney]

With all of the stitches and pins and metal plates in my body, I understand making the most of disabled parts.

In my heart of hearts I knew you supported a complete cooling system, but for a fleeting moment I thought maybe, just maybe, I could finally snatch the pebble from your hand.

The next time I see you I am not going to hit you with a stick, but I am going to ask you how you are getting along with your new pocket knife....

[Kevin Mienke]

The next time I see you I am not going to hit you with a stick, but I am going to ask you how you are getting along with your new pocket knife....

The next time I see you I will be driving a 1961 WM300 with the original 251 c.i. L-head engine. It will be running at 180 degrees unless I overheat between here and there, in which case I will remove the valve from the thermostat, installing only that large, sheet metal disc that remains. (only until I get it to a repair location)

The knife will be in my pocket. It is always either in my pocket or in my hand.

[Gordon Maney]

The next time I see you I will be driving a 1961 WM300 with the original 251 c.i. L-head engine. It will be running at 180 degrees unless I overheat between here and there, in which case I will remove the valve from the thermostat, installing only that large, sheet metal disc that remains.

The knife will be in my pocket. It is always either in my pocket or in my hand.

Always.... Hmmmm.... The picture I am getting is that you are holding it in the shower and perhaps also in the bed.....

[Kevin Mienke]

No...however Momma has been known to bear arms when I come to bed.

[maineSS]

From the efficiency standpoint, hotter is better- if your equipment is rated for it. At some point, you have to think about oil cooling, especially in air-cooled applications.

Evans has developed a waterless polyproplyne glycol coolant that adresses the corrosion and boiling point problems that plague water-based coolants. Some interesting info here http://www.evanscooling.com/water-ba...fferentiators/ . (This is not Sierra- that has water). This stuff is not cheap, and it requires complete dewatering of your cooling system, but it does last a very long time, and stops the corrosion & scale issues that water always brings. For antique vehicles, it has the big advantage of working without need of a pressure cap.

Hard water scaling can be a real problem when people don't use distilled water in their cooling systems. Depending on the mineral, it can have about 2-8% the conductivity of cast iron or steel- it's about the same as firebrick.
It takes a very thin layer to start causing serious problems (about 1/32") that might not even be traced to the cooling system. Aside from cylinder or head cracking, things like ring failure, excess oil consumption, bearing wear, etc, can have their origin in overheated, thinned out oil caused by high engine temps. Since scale is a very effective insulator, it's possible for coolant temps to actually decrease- you'd have to monitor exhaust temp to catch it.

There's always been a controversy about coolant velocity thru engines, and whether it's possible to "flow too fast". If you look at some of the torturous twists, the amount of 90 deg turns and abrupt cross section changes in an engine block/head, you'll see that "too fast" is NEVER going to be a problem. The quicker you can circulate, the faster you carry heat away, and the better you can prevent film boiling from starting on the really hot surfaces. The big challenge is having enough rad surface and enough air circulation around the block in the engine compartment to carry excess heat away. The thermostat is a vital component in managing this process- don't leave home without it!

[Daewoo10356]

that is an interesting post mainess I have never thought of the scale acting as an insulator keeping the heat in the iron but makes total sense gonna think long and hard the next time before i use the garden hose to top off the radiator