I recently removed my thermostat. No need to woory about freezing temps I live in AZ. Anyway according to mil1on a cooler running engine causes wear. Is this true. I always thought a hotter running engine causes wear! By the way I have a 1990 Bronco. It has a 5.8L (351W)!

 

An engine that isn't up to operating temperature has possible clearance issues and slow moving lubrication. Using a thermostat brings the engine up to optimum temperature faster.

 

Electronicly controlled engines use an engine coolant temperature sensor to allow the computer to adjust the spark advance and fuel/air mixture to match the operating conditions. Removing the thermostat only defeats your purpose if you are trying to increase performance.

And yes, it can cause increased wear because it promotes the buildup of moisture inside the engine, which promotes corrosion and formation of sludge. Also as Quantrex said, cold oil does not flow as well. So if you are extending the time it takes for the engine to warm up, that could cause accelerated wear.

 

[updated:LAST EDITED ON 08-Dec-02 AT 12:43 PM (EST)]I read somewhere that what really verifies this issue is the bore wear on a 6 cylinder engine. #1 and #6 cylinders always have more wear than the other cylinders, and this is attributed to them being on the end of the engine, and especially #1 which is near the water pump. They came to the conclusion the cylinder that ran cooler, had the most wear.

 

i'd say stuff a 180, or 170 stat in it just to be on the safe side.

 

On the other end of the spectrum, I've heard that running with no thermostat actually causes the engine to run hotter because the water is not held in the radiator as long. I'm not sure if this is true for street vehicles, as the guy who told me that was talking about why they run a restrictor in place of a thermostat in race cars.

 

[updated:LAST EDITED ON 08-Dec-02 AT 08:04 PM (EST)]A thermostat has two purposes. It holds the coolent in the engine during start up, allowing the engine to warm up faster, and then near the end of warm up it fluctuates between open and closed dependent on the coolent temp in the block, for the same purpose. Once fully warmed up, dependent on the temp rating of the thermostat, it will stay partially open, restricting flow to the radiator so coolent in the radiator can cool. If the coolent in the block reaches too high a temp, the thermostat opens further allowing cooler fluid into the block, which then closes the thermostat some and on and on... This gives a similar effect as the restrictor in race cars someone mentioned, but restrictors are used because race cars generally run hotter then street cars, and a thermostat would open wide most of the time.

This can lead to a mistaken belief that running without the thermostat will let the engine run cooler, as coolent is not trapped in the block. But usually the reverse is true, because with coolent continuly running full blown through the system, it looses cooling time in the radiator, and eventually the coolent will reach an overall temp for which the radiator has limited effect.

That doesn't mean you will have trouble not running a thermostat. I've tried it before, but about half the people I've talked to who have done this (including myself) have eventually overheated.

 

 

Something else to consider; the coefficient of friction between Aluminum and Iron is [font color="red"]lowest[/font] at about 215^ F. The friction between Iron and Aluminum rises rapidly starting at about 180^ (and lower).

Also, a warmer engine will vaporize fuel better and prevent it from washing the oil off the cylinder walls.

And, when raw fuel gets into the combustion chamber, it can get past the rings and dilute the oil which will cause more friction on all the moving parts.

In addition, a warmer engine will boil off water vapor and gasoline that get into the motor oil. If the engine stays too cold, the water and fuel don't get a chance to boil off. The water will combine with combustion by-products and form acids that eat the bearings.

Is this enough reasons to use the hottest thermostat you can find for your car? I'd suggest a 195^ thermostat. And, don't use too much anti-freeze. Anti-freeze has a lower specific heat than water, something like 2.2 vs. 4.5. Optimum mixture is about 40/60 or 30/70 AF/water.

 

So what your saying is it is better for your engine to overheat!!

 

These are experienced people trying to give you advice. You come in here, and proudly announce that you have removed you t-stat. They say you are killing the engine, which I agree with. You laugh at them. Fine, go ahead and kill your engine. Most of the people here care that Fords stay on the road, but you do not. Ask Dennis (mil1ion) for links to all the similar forums, as the search option is down. You will see, this has scientific basis, not just a bunch of people saying, now don't do that. Go ahead, kill your truck. Just don't cry to me about it.

Jared

 

Relax, Jared, I'm pretty sure he's kidding dude.

'77 F100, 302 (the aftermarket Prodigy), C4
Cadet Second Lieutenant John F. Daly III
South Carolina Corps of Cadets, The Citadel
The TorqueKing

 

te message boards are to ask many questions. taht is what they are here for. I'm not laughing at anyone.

 

I think you have your answer ... the thermostat will keep your engine living longer ... and it will reduce engine wear.

The most engine wear actually occurs during cold starts ... even if you live in AZ ... room temp oil and engine coolant is still considered a cold start. The faster you get your engine up to full operating temperature ... the better off you are.

Here is just one more reason/indicator for you ... and some extra advice for any of you living in colder climates. Have any of you ever rebuilt an engine that has spent it's life in freezing temperatures during the winter months?? I have ... and the last one that I took apart showed MUCH more cylinder wear on the cylinder bank opposite the block heater. Why?? ... because that cylinder bank was not as hot as the side with the block heater during all those cold winter starts.

For those of you in the cold winter areas that need to plug your truck in at night ... do yourself a favor ... run dual block heaters in your engine. Not only does it help prolong your engine life ... but it takes half the time to warm up when the temp drops below -30C ... and you forgot to plug it in the night before. Of course if you live in AZ ... this isn't anything you have to worry about.