160? or 200? Thermostat?

[Wm Steed]

When I worked in the auto industry during the mid 1950's the procedure that applied to the installation of a thermostat, new or used, was to place the stat in a pan of cool water, place the pan on a hot plate, as the water heated up the temp was checked to see when the stat started to open. As a general rule the stat would start to open a few degrees prior to the set temp and would be full open by the set temp, however, some stats would be sluggish.

Human nature being what it is..... how often did we do this?  In some shops it was S.O.P., others would get real upset if you even mentioned such a thing. How often do I check a stat?..... Every time I install a stat I tell myself I should check the new stat, do I do it?... no!  I just assume it will work because the part is new.

I purchased a one owner 1963 Chrysler 300 last year, with under 100,000. miles.  A beautiful car except for the general maintenance of the engine, especially the cooling system. The radiator was a rusted up mess, as was the block.... rusty water in lieu of coolant and no thermostat. The engine was running colder than a mother in-laws heart. I flushed the block out by removing as many soft plugs as I could, replaced same with new brass plugs, recored the radiator, new hoses and a NEW 180 STAT with a 50/50 mixture of coolant and distilled water on top of which I placed a new cap with 13lb.s of pressure. I installed a new Chrysler electronic ignition with new wires and new plugs..... Wha-La... the car runs like a new one.

Why coolant in lieu of water for use here in sunny So Cal?... Simple ....a 50/50 mixture of coolant with 13 lbs of pressure will raise the boiling point to approximately 280 degrees in lieu of 212 for water, while at the same time keeping the system free of rust and scale....Bill

[12905]

Bill Steed is absolutely correct. Basically, the hotter an engine runs - without the coolant boiling - then the better the performance and most certainly the longer the engine life. There is simply no good reason for running an engine without a thermostat ever! As for Carla's comment about California weather being warm enough, to eliminate the need for a thermostat, it is simply not so. I lived in sub-Saharan Africa for a period of time in the seventies and the weather there makes California seem like the Arctic. Nevertheless, our whole fleet of cars and trucks had thermostats - 190 deg - as well as oversize air conditioners, and they stayed at operating temperature at all times unless a cooling system malfunctioned or was neglected.

[36 Ply]

For Wm. Steed,

Bill, I always enjoy reading your posts, and I've learned a thing or two from them.? Sometimes, it is a different or better approach to something I was already doing.

When I mentioned thermostat failures in my cruisers, I was just telling a story. I had a total of? 11 cruisers during my career, everything from a '68 Olds Delmont 88 to an '88 Chevy Caprice, so two thermostat failures is really not that significant.

I have gotten bad thermostats right out of the box; that's why I test them now before I install them. I've also gotten bad spark plugs right out of the box; this can be frustrating when they are for a single cylinder lawn mower. My troubleshooting skills aren't top-notch; I have gotten a bad brand new part before, and when the repair didn't work, I blamed my troubleshooting skills.

My '52 Willys CJ3-A and my '98 Ranger do have thermostats in them.

Regards,

Pat O'Connor

[Wm Steed]

I would suggest that the readers of this topic scroll back to my posting on 11/24/05, which was posted in response to the original question by 'mvair' on 11/21/05.
One would think that in this day and age with so many people being well educated and enlightened, that the responses to the thermostat question would be more consistent and in line with good engineering principles in lieu of 'old time beliefs'.  ::)  The purpose of the thermostat is not to make the heater work better in the winter, it primary purpose is ..... TO MAKE THE ENGINE RUN AT A CONSISTENT TEMP, and thereby minimize the formation of harmful acids in the engine and to encourage a more uniform burning of the fuel.

Yes thermostat's fail as do brakes, tires, etc., so are we to discard these items to eliminate failures....Bill   

[John Hendricks]

which ever thermostat u use, remember there is a "correct" and an "incorrect" orientation of the thermostat in the housing.  I don't remember now, but it is in the manual.

[53coe]

You need the Thermostat, I also have owned cars that I took out the thermostats, that was a long time ago. My back ground is marine engines, outboards and inboards and stern drives. mostly Mercury marine products, after many years, just over 26 yrs. What I've seen and what Mercury has seen is when the engine is not run up to 160-180, the fuel burn will be higher, the oil will not last as long as it should and the biggest problem is that you will get excessive cly. wall wear, I've seen oval shaped cly. walls. When the engine is built all the cly. wall to piston clearance is based on the block running at the designed temp. If you think about most intake manifolds that has a passage to get the carb. up to temp.. I've seen some V/8 mopars that the cross over port in the manifold had gotten plugged with carbon and the engine would run rough, due to the carb being to cold. I will not run any of my cars or trucks with out a thermostat now., JUST my 2-cents., I also use 100% synthetic oil in all my cars, new & old, from my 50 P-20, 59 Fords to 05 Dodge Charger., Thanks and Merry Xmas to all, Wayne in sunny FL.

[Carla]

I run our vehicles without thermostats also, but we're in the S. F. bay area of California where we just don't have the sort of winters as do many other areas. Our winters here can be unpleasantly rainy, but temps below freezing are extremely uncommon. (it has happened, to be sure, and I've scrambled to get some anti-freeze in our vehicles after cold-weather warnings.....but not very often)

I've experienced overheating problems with bad thermostats, so I just leave them out, when the vehicle is being used only in this area, where our 'weather problem' is heat in the summer months.

In 'cold country', in winter, I'd do as the old tradition calls for....run a 190 deg. thermostat in winter, and either none or a 160 deg. in summer.

[36 Ply]

Back when I was an IL state trooper (1969-1993) I had two thermostat failures in my cruisers.

1975 Gran Fury (stuck open in the dead of winter), 1983 Diplomat (stuck closed in summer, got the coolant really boiling in the plastic overflow bottle).

I've also had bad thermostats, brand new, right out of the box, so I don't install them anymore until I test them. I tie a string to them, and suspend them in a pan of water, which is heated to a boil. I check the temperature with a candy thermometer, and see if the thermostat opens at the temp which is stamped on the housing.

I am not presently using a thermostat in my '36, but I don't necessarily think that no thermostat is correct for all situations.

Regards,

Pat O'Connor

[Wm Steed]

I have been driving for almost sixty years, I have owned my own car since I was fourteen.  During all of the years that I have been driving I can truthfully say that I can only remember two instances where a thermostat failed to function.  One of the stats stuck on a 36 Ford I was driving on the Baker CA grade in 1955 causing the engine to overheat and blow a head gasket. The other time was in 1978 when I was taking my daughter up to Idaho State U. from California, we were in the Nevada desert in August and the stat was hanging up causing the engine to run hot.  I was able to nurse the pickup into Ely Nevada  where I had the stat replaced.  I consistantly drive vehicles in excess of  100,000. miles which usually occures in three to four years.

Engines and the vehicles they are placed in are designed to do a specific job, through the years I have found that when a person sets himself up to do things with a vehicle, or too a vehicle that is contrary to what the vehicle was designed to do, then a whole chain of events usually transpire which can result in poor overall performance and/or a shortened life of the vehicle if every aspect of the modification (s) are not addressed.

In other words, I learned a long time ago to....... NOT LET THE DIRECTIONS ON THE CAN OUTSMART YOU....Bill

[57plymouth]

Yes >:(, they always seem to stick in the shut position when I am running late, in the summer, in traffic.  Once I have the water neck sealed down, it's there for life.  One less thing to ruin my day.

[UPSbusinesscoupe]

wow 57, may I ask why you choose to do that? have you and thermostats had bad relations in the past? :D

[57plymouth]

Okay, time for a Southerner to start a fight...

I don't use a thermostat.  I have not used a thermostat in my 57 since I started driving in in 1990.  Further, I don't have a thermostat in my 1980 Dodge truck, my 1956 Ford tractor, my wife's 1991 Z-28 (TPI motor) or my wife's 1969 Camaro (small block).  I have never experienced any trouble, but it takes an extra 3-4 minutes to get the heater going. 

Let the lashing begin!

[Wm Steed]

Jim is correct when he says that it used to be the norm in years gone by to change thermostats from winter to summer. Tod also mentioned the differance between the older style alcohol based antifreeze and the modern perminate types.  The reason why the alcohol based antifreeze was drained out in the spring was because alcohol boils at 180/190 where-as water boils at 212. The alcohol base antifreeze was also very corrosive where-as the perminate type is not.

The technoligy and/or missinfornation surrounding the use of 160/180 therms is as old as the cars we are working on. If one looks in the factory books, I think you will find that the factory recommended 180. As a general rule the higher the temp,, the more effecient the operation. When I went through auto mechanics school in the early 1950's the standard we were taught was that 180 was the idea temp, now this standard has been raised to 195.

I can state from first hand experience that during the early 1950's when I worked in the auto maintenance/repair field, we would encounter oil that was drained from vehicles which would burn the skin on your hands/arm from the acid content. The buildup of acid and/or condensation in an engine as a result of low operating temp's is one of the reasons older engines did not last very long.

Several years ago I owned a company that had a large fleet of vehicles ranging from cars to heavy trucks. We maintained most of the vehicles in our own shop using Castrol GTX 20/50 which we purchased by the 50 gal drum. Some of the light pickups (El Camino''s) and cars we allowed the operators to drive them home and have them serviced at a local station,, however, they had to use the GTX 20/50 which they could get from our shop or they could purchase it locally. One of our employee's drove a 79 El Camino we had which he was allowed to take home, he had the vehicle serviced at a local station that was close to his home. When the engine had 80,000 + miles on it, it seized, when the engine was torn down we found that it had failed because  it was all sludged up almost beyond belief.

I called the Castrol rep, upon investigating the matter it was found that the engine had not been running on Castrol, we also found that the therostat had been changed to a 160 in lieu of the 195 it should have had. Further investigation revealed that our employee had purchased the GTX oil but he had used it in his Porsche, substituting the cheapest MS grade (non-detergent) oil for the company car. He also had the thermostat changed because he thought the 160 was better.

Moral of the story, the old ways are not necessarily the best way..... and yes we terminated the employee....Bill

[mvair]

Thanks for the information.  I notice also that the service manual only mentions the 160? thermostat...so that must have been the standard choice.  Since I live in California where the temperature only gets below freezing once every 3 or 4 years and my car doesn't have a heater, I will use the 160? option.

[Jim Benjaminson]

One thing to remember with the 160 vs 200 degree thermostat.  It was fairly common in cold climates to install the higher temp thermostat for winter driving and then switch back to the 160 for summer months.....

[TodFitch]

One more consideration. In the old days alcohol was still in pretty common use as antifreeze. If you are using alcohol then you need a low temperature thermostat so that it does not evaporate.

[TodFitch]

In favor of the higher temperature thermostat, generally your engine oil will stay cleaner the hotter it is. The heat allows the water and other blow-by combustion products to evaporate off and be extracted by the crankcase ventilation system. And you heater will put out more.

In favor of the lower temperature thermostat, you have a bigger margin between when the thermostat is fully open and when you hit boiling.

I run a 160? thermostat in my 1933 and simply change my oil fairly often. I don't really need great heater performance where I am. And I do like to see some space on my temperature gauge from my normal operating point to the boiling point.

[mvair]

I have a '41 with original engine.  I am replacing the thermostat.  The parts books shows two choices; 160? and 200?.  Why the difference and which one should I use?