Lots of data points - I'm surprised how many people have done it even with the opponents screaming "you can't do that!"

Lots of people also chiming in here who don't have any first hand experience, with a lot of hearsay and regurgitating.

My data point...
I've been running with a cored thermostat for 5 years prior to removing the cored flange two years ago.
(I lost the flange while doing some maintenance at that time, so I never bothered to replace it since then.)
My car still runs fine.
No, it doesn't overheat.
Yes, it does take slightly longer the warm up.
Down here in Hawaii, the temps rarely go below 70F on ambient - this is kinda important.
Yes, the car gets bad mileage - even with the E8, I barely get 10mpg on purely city, and when I get the freeway jaunts it's a little over 15mpg.
These numbers are pretty bad for an FC.

I run a *STOCK* radiator.
I have no plastic engine underpan.
The AC condensor core is still up front.
I run an electric fan controlled by a Spal FAN-PWM - 50% set at 190F, 100% set at 215F.

The bypass doesn't affect cooling efficiency unless you're doing serious revs - over 4kRPM sustained.
This is why RACERS will plug the bypass hole.
For a street car under normal driving conditions, it fricken doesn't matter.

The guy just wanted to drive down 30 minutes to get the proper part.
This is not going to hurt his engine with the exception of some slighty degraded gas mileage.


-Ted

 

Oh man HELL YEAH you could run without TS I have never ran with one for the longest. If your running a stock fan make sure it's good working condition, if your running a EF make sure you got enough cfm to push out to keep you running cold. Other then running a TS is not that vidal to your engine. Some people would tend to think so but in my opinion it really doesn't make and difference. You will be fine.

 

Nobody has said it's vital, but saying it "doesn't make any difference" is stupid. If thermostats didn't make any difference they wouldn't be fitted to every single production engaine made for decades.

There are absolutely no advantages to running without a thermostat, only disadvantages. The only reason to do it long-term would be pure laziness...

 

Does the bottom half of the thermostat open like the top half when heated? I've been testing I and only the top half opens. Its an OEM mazda ts from rx7stor

 

It makes you think about the 1000's invested in the car and a 20 dollar part that people overlook that can bring the whole car to a Grinding halt.
Get a thermostat..don't cheap out!.(and your car will love you!)

 

+1

 

+2, been running on my stant since sept of last year. No issues, sits below 1/2, never goes above where it sits.

Did it for temp 10$, dealer is over 2 hrs away. I only drive 10 miles a day, always keep an eye on temp, anyways.