Is it really bad to leve out you thermostate?

[mikes68charger]

My charger kept overheating 245 + after driving for 15 min or so. So I put my electric fan on the puller side of the radiator and this did not help, My hoses were warm but not hot, I ran it without the radiator cap to release any air bubbles and it still overheated. I pulled out the thermostat and the hots it got was 190 and ran about 160 when cruising. I drove it for 30 min with no problems. ( which is the longest I have every driven my baby  ) should I even put one back in or just leave it out. What temp range should I install ? what is the Ideal temp to run anyway?

[charger Downunder]

Check your thermostate by boiling it in a pot on the stove and see if it opens. i use a 180 thermostate,Radiator core cold be partly blocked.

[Chryco Psycho]

 if ti si working you can do it , usually it will run hotter without a T stat  if the T stat is working correctly

[deputycrawford]

my opininon is to run a 180 thermastat. No thermastat wil not slow down the coolant in the radiator and It will actually run hotter. Check all the hoses for wear and put it back together. From the sounds of it you had a stuck thermastat.

[grouseman]

Classic case of a bad 'stat.  Run a 180 minimum.  If the hottest it got was 190, you're in not bad shape. 

[Rolling_Thunder]

here in CA we just run a restrictor plate...      no T-stats here

[RD]

i run all (but my neon) without a thermostat during the summer and have never, ever had a overheating problem.  Did I say ever? Yep, ever.  Matter of fact, during the 100 degree stint of weather we had in august, my 318 truck had to fight to get to the 2nd bar on my temperature gauge.  That is the highest it has ever had gotten too.  The temperature that day?  109 degrees fahrenheit.

I have to put in a thermostate in the next 3 weeks (which I will change out my coolant also) in order for my vehicle to even warm up during this time of year.  that is on a 318 4bbl 81 pickup and a 87 ramcharger with a 400 4bbl.  Both have fans, fan shrouds, and no coolant leaks.

[grouseman]

RD, you are actually doing harm to your engine by running it so cool all the time.  Not to mention reduced mileage.  The engine should be running 180 MINIMUM. 

[RD]

RD, you are actually doing harm to your engine by running it so cool all the time.  Not to mention reduced mileage.  The engine should be running 180 MINIMUM. 

define harm.  I get around 16-17mpg with 3.55's in a 1981 dodge pickup.  318/4bbl to boot.  Should I be getting better gas mileage than that?

[grouseman]

The mpg improvement will be there; no way to tell if you'll get 1, 2, or 3 or more mpg.  If you've got an EFI system, the temp sensor is telling the computer to enrich the A/F mix; it's like your choke is partially closed all the time.  If you've a carb and the choke is coming off, there won't be as much mpg improvement as long as you're getting good vapourization from the heated crossover on the intake floor.  Then again, you're already bringing in 100ºF air.  Also, your oil is not getting to the proper temperature to evaporate moisture that develops in the crankcase, so you either need to change oil more frequently or you're going to increase your sludge buildup.  Finally, your engine was built with design tolerances expecting the engine to run at 195 or so.  If you are running at 120 or 130 or whatever, you could be generating more blowby, and/or more wear because of dissimilar metal expansion rates like with aluminum pistons and iron cylinder walls. 

Do a google for oil & engine operating temps, engine wear, etc.  The research is out there. 

You can at least rest assured knowing that your cooling system is performing great.  Even if you do put in a 195 'stat, your engine will NEVER overheat.  You've also disproven the myth that running no 'stat will allow the engine coolant to run through the radiator too fast, not giving it time to blow off heat, thereby causing overheating. 

[RD]

thanks for the info.  learn something new everyday!

[daytonalo]

All cars will run far cooler without a stat , including new cars . The efi will make it run richer which will give approx 20 horse , ask any tuner guy . As far as older cars go as long as your cooling system 100% , running a engine @ 150 will do no harm , and it is true you will have to change oil more  often , engine life will be greatly increased ! I run a 540 CI ,600Hp in my offshore race boat , and I run no stat with fresh water cooling and , it runs 130 all day and  I have to date 300 HOURS AND I RUN THIS ENGINE 90%OF THE TIME @ 5500 RPM ! Heat is the biggest cause of engine failure along with that comes elevated oil temp with is a death sentence for any engine . you heard me 5500 90% of the total time on this engine !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Ghoste]

Boat engines don't use a radiator though do they?  (it's not sarcasm, it's a serious question btw)

[694spdRT]

Boat engines don't use a radiator though do they?  (it's not sarcasm, it's a serious question btw)

Our inboard uses a 800 acre radiator that is about 25 feet deep.   

[73Charger]

I have run colder stats on summer only cars that you don't care about heat in - 160 degree.  Ofcourse, I'm not sure if the temp makes a difference on the type of block...

[daytonalo]

One has to remember what increased engine temp means , higher oil temp ,which Leeds to lower lift rates on a hyd camshaft .

[Rolling_Thunder]

but also keep in mind guys - engines have to run a a set degree - otherwise thermal variance in the blockwill cause the bores to wear quicker....                                               so im told -  anyone wanna tell me im wrong ?

[daytonalo]

Again I have three seasons , and over 260 hour and I run this engine @ 5000 rpm 95 % of the time . Thats 5000 not 500 . They want car engines to run warmer so they can run cleaner , but that is bad for performance and longevity . I  have been doing this for twenty years , and wouldn't have it any other way , I just wanted some of your experiences , not speculation !!!!!!!!!!!!!!

[grouseman]

Here's some more information for people to read up on regarding oil, engine temp, longevity, and performance. 

http://www.carnut.com/ramblin/_cool3.html

[PocketThunder]

Here's some more information for people to read up on regarding oil, engine temp, longevity, and performance. 

http://www.carnut.com/ramblin/_cool3.html

that was good reading.  i learn something new everyday from the people on this website...

[Steve P.]

All cars will run far cooler without a stat , including new cars . The efi will make it run richer which will give approx 20 horse , ask any tuner guy . As far as older cars go as long as your cooling system 100% , running a engine @ 150 will do no harm , and it is true you will have to change oil more  often , engine life will be greatly increased ! I run a 540 CI ,600Hp in my offshore race boat , and I run no stat with fresh water cooling and , it runs 130 all day and  I have to date 300 HOURS AND I RUN THIS ENGINE 90%OF THE TIME @ 5500 RPM ! Heat is the biggest cause of engine failure along with that comes elevated oil temp with is a death sentence for any engine . you heard me 5500 90% of the total time on this engine !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

You are not comparing apples to apples. Your off shore boat has 998 gazzzzzzilion gallons of water that is under 140 degrees. A car has a few gallons. If you DON"T run a t-stat in a car it will not run cool. It will for a while, yes. The tuners you are talking about are running down a 1/4 mile strip. Then they shut them off till cool again for the next round. You go right ahead and try to run any car without a stat on a average temp day. Stop at a few lights and wait for a few school buses. See how far you get before you over heat or worse, blow a motor.  Cars that are strictly for racing 1/8th mile or 1/4 mile can get away with it depending on how much heat they make and how long they have to wait to make their pass.   A street driven car WILL NOT keep from overheating during daily average use.

Mike, your answer is YES. It IS bad to leave out your T-Stat..  Grouseman posted from CARNUT. This is just one test done. Over the years there have been many and they all end up with the same results. 180* stat is the best for most cases.

[daytonalo]

The hotter the better ! Get water temp to 220 and oil temp to 300 , and the fun begins !

[Steve P.]

The hotter the better ! Get water temp to 220 and oil temp to 300 , and the fun begins !

No one is saying, (THE HOTTER THE BETTER). No one want their water temps at 220.. That's normally the point were things start to really go bad.  Your comments here could really be confusing.  Many people here have never experienced a blown motor or cracked head or even know where to begin looking for an overheating problem. Your experience with OFF SHORE RACING is an entirely different ball park.  There is no way you are running your car or truck WITHOUT a T-STAT..... Not in traffic..

I spent many years working on cars for a living. To tell people it's OK or even better for them to not run a thermostat  is ludicrous...   

Like I said before, your off shore boat has an ocean of water under 100* to cool your engine. Cars only have a small radiator with a few gallons of water to cool their engine. Without a thermostat to stop and hold water in the radiator, the fan cannot cool the hot water running through it fast enough.

[firefighter3931]

Thermostats are a necessity on any street driven car, inmo. If the cooling system is working prioperly then the stat will regulate the temps. I've seen a few super efficient aluminum rad cars that ran at 140* w/o a stat which is too cool...at least for my liking. Those cars ran better at 160* from what i remember.

A race boat with a million gallon rad is a whole bunch different than a closed 3 gallon water/coolant system that is operating under pressure. I wholeheartedly agree with Steve on that one. 


Ron

[Ghoste]

That's kind of why I was scratching my head over the boat radiator question when I asked it.