Running without a Thermostat, how bad

[TechnoLoGs]

How bad is running without a thermostat? I discovered that my vehicle did not have a thermostat for a very long time. My heat blows hot when the radiator has full amount of water in it so I do not suspect it to leak or be clogged.

I purchased the OE 192F failsafe thermostat for it. Or, a failsafe 192F stat, since the OEM ones stick closed, not open.

If I put the stat in, what differences will I notice?

 

[NMBurb02]

Engine will warm up much quicker resulting in better fuel economy and less wear and tear on the oil (due to oil also heating up faster) and engine in general.

 

[Azeem]

Originally Posted By: NMBurb02
better fuel economy


How's that?

OP,your heater won't work at least.

 

[SuperDave456]

Better fuel economy because the whole engine is running cooler than it should be for a longer amount of time.
All the oil's, both engine oil and Transmission fluids, are designed to run at a specific temperature, hence the need for a thermostat.

If you don't have a thermostat everything is cooler, and therefore thicker, thicker fluids require more energy to move. Energy comes from somewhere.

Depending on how you drive (lead foot or like a granny), the ambient temperature, and how far you drive, you should see a good increase in MPG.

 

[EricF]

You'll get better fuel economy because the car will go into closed loop mode much faster, and it will help with the environment in terms of smog.

 

[Tegger]

Originally Posted By: TechnoLoGs
How bad is running without a thermostat? I discovered that my vehicle did not have a thermostat for a very long time.

Aren't you the same guy with the car that had no air cleaner? What else is missing from this car?

 

[Darren270]

Am I really reading these responses right? Better fuel economy? Or is this a joke that I'm not getting? Because you will NOT get better fuel economy.

 

[Pajamarama]

Originally Posted By: Darren270
Am I really reading these responses right? Better fuel economy? Or is this a joke that I'm not getting? Because you will NOT get better fuel economy.


You will get better fuel economy. I bought the used Accord in my sig and was getting 22 mpg per tank on average. I noticed it took a looong time to warm up and figured the thermostat was broken. When I took a look, I found the thermostat was entirely missing! When I put one in, my average mpg rose to 24-25 per tank.

But...I think a missing thermostat is a warning sign. Someone obviously took it out for a reason, and probably not a good one. Shortly after I replaced my thermostat, I started loosing coolant. Turned out the missing thermostat was used to (partially) hide the fact that the head and block were both warped.

 

[mechtech2]

Originally Posted By: Darren270
Am I really reading these responses right? Better fuel economy? Or is this a joke that I'm not getting? Because you will NOT get better fuel economy.

Totally wrong.
The hotter the engine, the less fuel is used to heat up parts,and more goes to power.
This is why Ford and others use dual rated thermostats - hot for cruise, and a bit cooler for power [less knock].

 

[Dave Sherman]

Better gas mileage because the computer raises the idle speed to make the engine warm up faster, and often the torque converter won't lock until the engine gets up to temperature. Both these things reduce your mileage. No thermostat? Engine takes much longer to get up to temperature, and may be running below that.

 

[Darren270]

I'm an idiot. I misread the OP. I thought he was asking what to expect if he ran it without the thermostat. I was reading the responses thinking, are these people nuts?? Now it makes sense.

 

[dishdude]

A thermostat actually helps with cooling. Without it, the water flows through the radiator so quickly it doesn't have time to cool down. At least put a cooler thermostat in, but don't run without one at all.

 

[ChemicallyChargd]

It doesn't help with cooling lol. It opens only when the water temp in the block has risen above the specified stat temp(usually around 185) and stays open until temperature has dropped back down or pump pressure forces it open at higher engine speeds. Your mileage will go up, due to the air being hotter and less dense than colder air from a colder engine bay. Cold air intakes work on this exact principle, colder air more dense means more fuel injected to match it.
-srv

 

[ChemicallyChargd]

It would be more accurate to say it helps keep the coolant and therefore the engine at the best all around driving temp.
-srv

 

[SHOZ]

T stat sets minimum coolant operating temp.

 

[babyivan]

Originally Posted By: TechnoLoGs


I purchased the OE 192F failsafe thermostat for it. Or, a failsafe 192F stat, since the OEM ones stick closed, not open.

OEM t-stats sticking closed is total BULLKAKA! they have always stuck open for me, ALWAYS!
And for the love of god, DON'T use the failsafe t-stat!!

Have you read any of the reviews on them, TONS nightmare stories of how they go into failsafe WAY too easily and then you needing to do the whole job all over again. Once they go into failsafe mode, they do NOT go out of this mode, you have to then replace it!!

Merely working out the air bubbles from the cooling system can activate these POS t-stats, forcing you to redo the whole job!

I did lots of research on this a few months ago.... "google" failsafe t-stats and read reviews on them from other forums, you will see!!!!

Also, if you're getting heat while running without a t-stat, then you are probably running HOT and have a cooling system issue! Probably why the t-stat is missing in the first place!

And, YES, running without one is not good in a proper working system, it can confuse the ECM into thinking the engine is not warmed up and thus running rich like it does when you first start it up in the morning. It's horrible for gas mileage!

 

[Errtt]

I think a lot depends on condition of radiator, impeller, driving habits, system pressure, ambient temp etc. etc.
The coolant needs time in the radiator to cool before returned to the block.
May/may not get away with it in some cases, but without a stat what's left to control/maintain temp from uncontrolled swings

 

[Virtuoso]

I've had a thermostat stick closed for me.

Most of the time mine have failed in the "open" position though. But don't assume they always do that.. sometimes they don't. And it sucks when they do.

 

[babyivan]

Originally Posted By: Virtuoso
I've had a thermostat stick closed for me.

Most of the time mine have failed in the "open" position though. But don't assume they always do that.. sometimes they don't. And it sucks when they do.
Granted, but it's less common for sure.

Those failsafe t-stats are no answer to that happening anyway! Ive read so many bad things about them, it's not even funny.

Also, if a "failsafe" t-stat happens to fail when it's closed, it wont be able to reach the locked open position anyways....
A regular thermostat won't fail when it's open and then snap shut like Motorad claims, when it fails, it stops right where it is and if that happens to be in a closed state (a lot less likely from my experience), well then that's where it remains, so their locking mechanism is a joke.

Those POS t-stats if anything are more for protecting you from an overheating issue much like removing the t-stat all together would... ironically enough, but as far as protecting you from the t-stat itself failing, not happening. Motorad doesn't tell you this for some reason, they claim that the locking position protects you from the t-stat itself failing, what a crock!!

The one thing I read all too often is that they react way too easily, causing it to lock, forcing you to redo the t-stat as I mentioned in a previous post.

To the OP (wherever you may be), check out the reviews....

From a Jeep forum

look at he 2nd post, the failsafe t-stat FAILED in the closed position!

yet another lousy experience.....

here's another....

When I did a search for reviews, I did NOT put "bad failsafe t-stat review" into the search bar, I just put "failsafe t-stat review". On the very first page comes up bad review after bad review!

Gates or an OEM t-stat is the way to go! Ive had a Gates superstat in a car once, they work great and are still made in the USA!

 

[babyivan]

Originally Posted By: babyivan


Gates or an OEM t-stat is the way to go! Ive had a Gates superstat in a car once, they work great and are still made in the USA!

Sorry I meant Stant, not Gates.... I have hoses on the brain, lol.