Will Your Engine Overheat Without a Thermostat? 

I say no, every single car I’ve ever owned and I live in Los Angeles the first thing I do is rip the thermostat out , newest car I’ve had was a 2017 Hyundai sonata, my Uber car, and I pulled the thermostat out. oldest I’ve had 1984 Chevy K5 blazer diesel no thermostat, my 1992 Chevy 2500. I ran it for five years with no thermostat, hauled countless loads of tile, 2 tons at a time, and towed many trailers with dirt, bikes, and camping gear along with my truck being full never overheated, and it still has not given me any problems. In fact, it’s better for my vehicles. I don’t know why maybe the climate I’m just telling you my experience. My opinion when you close off the water flow that’s bad for the water pump because the water pump is working overtime to try and pump water through a closed system. If you remove that thermostat and open everything up, there’s no resistance and it saves your water pump and keeps the water free flowing now if you’re in a climate, that’s freezing cold or even blistering hot that’s where you’re gonna need a thermostat. Other vehicles I’ve done this with include, 98 accent, 88 and 92 Nissan hardbody,89 s10 pickup, 02 tundra, 02 accent, 92 FZR600r, 94 zxr750r, 07 fjr1300r , none of these ever gave me any overheating problems after removing the thermostat.

Minivan was seriously overheating, took the thermostat out 2 months ago, now it runs great, even on hot days and long drives, no more overheating issues at all, bought a red dot lazer thermometer early on to check the temp of the radiator hoses and the head and the block, normal engine temps around 200 degrees, the minivan now runs at a consistent 165-180 degrees.

That was very clear and understood good explanation.

Thanks for clearing up the confusion. I have been losing coolant/water from the expansion overflow due to it boiling over when the engines hot. It was due to the thermostat being stuck closed. Told local garage and the guy told me to remove thermostat and leave it out he said it will run cooler? Fan still comes on and bike runs rich a week later. Gonna get a replacement right now!

Hi, ur video is short sweet and straight to the point. Thanks I've got a new follower

Thank you sir, very useful information. It clarified some myths. Thanks again.

This video answered all my questions, awesome!

Great video! very well explained.

Thanks bro, your explanation was perfect

Running an engine without a thermostat can make the engine run hot or overheat. Nearly all modern engines require the lower half of the thermostat to close the bypass and heater side of things as the engine gets up to temperature. If this port is not closed or restricted, a large amount of the coolant flow will not be pushed into the radiator for cooling. The water will recirculate within the engine getting hotter because the water is not forcefully flowing through the radiator. As a result the radiator will appear to be cool but the coolant within the engine can be high. You might have got away with that sort of hack 50 or more years ago with the very simple thermostats but not nowadays. I have also seen old systems without thermostats overheat on hot days because the coolant was simply flowing too fast through the radiator to cool properly. I used to modify radiator tanks with baffles to make the coolant pass through more of the radiator cores. And as far as thermostats controlling the engines coolant temperature, you are correct that it controls the minimum water temperature but it also regulates the flow of coolant of which controls the coolant temperature over a range of engine power output. The thermostat starts to open at the minimum temperature, it does not spring fully open. The thermostat modulates the flow of coolant through the cooling system and in turn keeps the temperature at a reasonably fixed temperature with varying power levels until the thermostat is fully open. When fully open, the temperature will continue to rise because cooling capacity limit has been reached and with more power comes more heat. The radiator has become heat soaked and unless more airflow or cooler ambient air or less power is commanded, the temperature will keep rising with more power. The whole system is engineered to be suitable for the vehicle it was designed for and any overheating issues means there is a problem with the system. If there is no problem with the cooling system, then it will be an engine or transmission problem or the vehicle has been modified or the vehicle is being operated outside the design parameters it was designed for. So, yes the thermostat does control the engine coolant temperature and is critical in making the engine run to comply with air emissions. A colder thermostat will make the normal running of the engine lower providing the heat can be removed by the radiator properly.

The only problems I ever had with thermostats, one stuck closed, another the middle section that opens and closes actually broke out somehow so it was just a restrictor hole for coolant flow.

thank you for the gr8 explanation

Thank you for video ..helps alot to understand how and why thermostat is important. Question if cooling fan not working ,already changed sensor switch and fuses not working still only when A.C is on what do you think would be next step? Thank you for help.Keep up the good work.

Good explanation!

Thank you for the definitive answer. Great🎉

Where can I find the women driving the Porsche ad commercial. I was watching and lost it lol. She said she was from CT. I found her, I was watching your videos, and this played Going Home with Bozoma Saint John. She’s the CMO/ chief marketing officer at NetFlix . Keep up the good work. The thermostat video was awesome. I’ll pass your video around.

Bought a ford taurus 2013 that after a couple of days of driving started to overheat and continued doing it at times intermittently over a week period,so i decided to check the thermostat and found that it had been removed so i replaced it also put some new coolant and it's been working fine so far,no heating...

Important information thanks

Thanks for the info 👍

Does the thermostat have anything to do with the amount of pressure in the cooling system? Both coolant lines on my 03 Impala (3.8l) seem to have more pressure building up during normal operating temperature.

Sir very helpful video👍

People that think a thermostat delete will cause overheating want to say, 'It wOnT hAvE eNoUgH tImE iN yOuR rAdIaToR!" Guess what, It also won't have as much time in your engine block, either.

Nuff said great job 👍🙂

Had a Ford 4 cylinder about 84 Escort. 2 cylinders weren't getting enough coolant. Warped and cracked head. The fix was the replacement head gasket restricted the flow making the coolant spread out and cool all 4 cylinders.

Instead of closed or open, can a thermostat be slow to open? And it's intermittent. Sometimes from a cold start it will warm to almost red before dropping back down to the mid mark - then its fine till the next cold start. I've had to pull over and stop twice to let it cool off.

Much of educational comments thanks guys.have my Subaru legacy that recently had head gaskets replaced and removal of the thermostat after its does 3000 k start overheating again like 20 min drive,after all the headless chicken run out of ideas I decided to open the rad was completely blocked of dirty so I got it cleaned and install new thermostat but still overheating down pipe stay really cold even I do 120km/h ..did research as much to find it be a stuck close thermostat so today will remove it and see what happens..I thank you guys for the info never ever read more that 50 but to this It's more than..all the way from Namibia

I had a Mercedes 300TE (3L straight 6 cyl) which needed a new waterpump because of leaking seals. It never overheated even on hot days in the tropics. I had the waterpump replaced and had a horrendous overheat problem within 20 minutes of driving. This problem was caused by the mechanic removing my perfectly working thermostat. So YES! It can cause overheat. The reason was no water back pressure at the thermostat which severely reduced water flow to the rear cylinders which caused coolant there to boil and dump the coolant out the radiator cap! A new thermostat fixed this immediately. However one year later my head gasket failed due to this. Some engines need the thermostat in for normal ops and be very cautious about running without it. Other engines are ok.

The Jeep JK OEM thermostat opens at 95 celsius while most of them in my country are operating at engine temperature above that, if you go up hill or offroad the heat will increase so we remove the thermostat which keeps the temperature stable and never over heats.

Had so many vehicles overheat, I took thermostat out and no more problems.

I used to own a 1979 Oldsmobile Cutlass Calais 5.0 V8 and it blew a heater hose the third day I had the car operating. I replaced the hose clamps with screw style clamps, the hoses to high performance heater hoses. When I went to swap the radiator hoses I checked and there no thermostat. So I installed a 190°f thermostat. The car never overheated and boiled over again. The coolant before and after the repairs was brand new.

GD ADVICE...LIKE YOUR UPLOAD

I recently had my head gasket blown due to the faulty thermostat that caused the car to overheat. Had the thermostat removed and driving the car without it now. So far its running pretty good.

Thank you sir

In the hot climate country, OK for thermostat removal since electric cooling fan is always on assisting cooling process. Thermostat removal to be follow by plugging the bypass line, if not then 50% coolant flow through radiator and other 50% through bypass line. This the common mistake for just remove the thermostat.

First start of eng in the morning (chevy Express 1500 cargo van ) it reads eng hot and wont allow a/c to work. Thermostat stuck in open or closed position?

Tried a lower temp stat and temp guage is much lower all the time.....bought a higher temp one now its just right.

Thermostats also get stuck closed. We're experiencing a new thermostat that opens later than the stock one, and the car starts to overheat before it does open. The thermostat does control coolant flow through the radiator and if it's staying closed, it's not being cooled down in time to cool the engine before the coolant begins to boil and escapes via the overflow.

Hi, can you suggest any thing to keep freelander 1 2001 petrol 1.8 ltr cool ??

Can you tell if your thermastat is closed taking it out of the housing? To be sure it is stuck? B4 cost invested in somewhere you do not have to spent? 1. New thermastat 2. Radiator 3. Water pump leak new gasket 4. Fan clutch Do what 1st. If engine gets hot idling then chug a lugs & dies.....to hot after a few minutes idling.

This video is very good

2013 Ram 2500 stock 205-210 degrees with 180 thermostat 183 all the time .. In Georgia heat.

I took the thermostat out of an overheated car that I bought for almost nothing hoping it was just that. It wasn't. The head gasket had blown and the head warped, likely from this completely closed thermostat, but without it I could almost make it home. Had I not taken it out, I would have stranded within 10 minutes. Roadside assistance got me the last 10 miles.

Does a thermostat help you with the cold start

Thank you

i live in Middle east with ambient temp of about 35 degreees centigrade, is it possible to remove the thermostat?

thank you so much,this is much helpful

Engine heating up not loosing water or coolant I just done water pump and it’s heating up quicker 2004 tekcuchi mini digger thermostat is out of it ?

It helps thanks

Good God why is the opening like 200db louder than the actual video?

Hee,hee!😁you're in the internet! Thanks for video.😉

the thermostat is a flow regulator to maintain temp. take out and coolant circulates to fast to cool down in radiator.

I’ve got an old rig with an Olds 403. Put in a thermostat and it runs hot. Pull it out and it runs good on warm days but too cold on cool days. I think I need a water pump. Thermostat causes a slight restriction.

If your overheating on a stock engine the thermostat could cause it if it's not opening or not all the way open but usually you have an other problem like air in the system or a blockage in the coolant system.

I disagree on a couple of points. I feel this is oversimplified. Thermostats do restrict fluid flow even when full open. Coolant temperature depends on multiple things, not just the thermostat. The amount of air across the radiator has a great deal to do with coolant temperature reentering the engine. If there is adequate airflow and proper coolant flow, a 160 degree thermostat will maintain that temperature regardless of engine load.

High at 3.07 certain vehicles operate very small radiators and will overheat when thermostat is removed . Why coolant flows to fast past cooling tubes . Cooling is functioning of pulley ratio // radiator fan // radiator size // water pump impellor design /// optional thermostat flow restriction //

My thermostat is showing bad and engine light is on. Can I drive it like 140 miles to the mechanic with out overheating or shutting down. It's a 2018 Grand Cherokee Laredo

I have a 1997 Okdsmobile Aurora that was overheating badly. I went to replace the thermostat and found there was none. So i put a thermostat in and it has not overheated since

so if we remove thermostat is it ok to the engine to work?

My truck ran hot with no thermostat & took forever to warm up,ran perfect with one in 🤔. it's not water cooling the engine it's a glycol type which needs dwell time to transfer the heat👍. If flow rate is too high it does not efficiently pull the heat out as designed.

good video

Hi i have chevrolet captiva some days before running car 15km without coolent and water after some days car ty to start but car dont turn on bcz temrature light turn on dear all what i do now

what about hot countries like sudan the temberature is som e times over 40. thanks?

Just took off mine and everything works perfect and no issues

if i would enable the thermostat to be open always,would my engine be always cold and would it be bad for the engine?

Good video. But there’s an option c to address which is a stuck thermostat leading to extreme pressure buildup , which greatly increases both engine temperature and will likely blow out gaskets and hoses. Running without a thermostat temporarily is okay while you’re waiting to replace it .

The heat gauge of the vecihle keeps going up, however the engine remains cool, i dont know what to do now

So now I have a question I work mostly with diesel engines and I always remove the thermostat to overheating problems and all of those engines lasted a very long time even for longer than original but people mostly say removing a thermostat is bad then why did I find any problems with doing that

Hello, my question is… my son traded his 04 F150 for a Honda Civic. He has it for about 4 days before it began overheating. We figured let’s start by checking the thermostat. So I go to swap it out, I get the thermostat housing off and “voila” there was no thermostat in there at all. Swapped it out drive around for a good while and so far engine temp has been in the middle of the gauge. Why would anyone remove the thrmstt.

Thank you. Just bought a 95 Tacoma 4 cyl. Started overheating when it was idling fir 4 minutes or so. Guy I bought it from says the thermostat is old and never replaced and it’s probably shut closed and that is why. Not sure how the fan works but it is spinning when engine is running. Is this true and can I flush it and run it without the thermostat just for a vew days untill I get the thermostat. Thank you.

I have an subaru that is blowing exhaust out of the head gaskets into the coolant and it overheats right away. But there is no heat in the car. Person told me pull the thermostat the car is overheating before the thermostat can open. He said I won't have heat inside the car but the car won't overheat from the exhaust gases.

I have a 89 k1500 350. It did good with 195 oem thermo last summer then winter came around and the temp was bouncing off 230 not okay with me so I replaced thermo no fix then water pump then radiator then coolant temp sensors then got system flushed I don't think it's cracked head oil and coolant always looks good nothing comes out of the exhaust bad. I finally gave in and tried a 160 thermo then I ran 190 rest of the winter now that summer is here it's creeping on 230 again. So I just tried a 195 thermo thought well that did good last summer maybe it'll work this summer. Well now the 195 makes it worse. So now I'm left with running no thermo and see what it does any help or advice be appreciated I'm at a loss at this point I'm confused

Regardless the opinion of the www and in spite of engineering efforts modern stats don't always fail open. The last two failures, mine and my fathers erred closed. Both Motorcraft my vehicle had 3400 miles. I am ocd like about temps while driving. I will ferret out a way to run sans a stat. Achieving a closed loop is not impossible w/o one. No stat beats a closed one every time.

I took off my thermostat on my Jeep Cherokee and it don't heat up no more.. We are in cold weather right now now the check engine light came out and it says check gauges and the temperature one it stays at low the whole time and it makes this noise in the engine like it needs air or something like forced to drive sound?

So question is it ok to take out my thermostat for just a few days? I have a 2011 Camaro lt. my fan works but my cat is running hot

4 factors, engine size, radiator size, coolant mixture and computer systems.

Will the flow rate have any effect on the efficiency of the cooling that happens in the radiator?

the hose harden but temperature gauge will be at operational temperature .is this okay

But hear me out, I own a Ford fiesta made on Brazil (and other places) here in Guatemala, parts are really hard to get because the official dealership has only parts for US fords (the ones they sell) and really hard to get from other places, so for me I think my best option is to run without one cuz they fail constantly in this model. What do you think?

My thermostat was stuck open and the engine was over-cool for at least a year of daily driving (the time I’ve had it). The temp stayed all the way down unless I stopped and idled for 10-20 minutes and even then it would shoot back down almost as soon as I started moving.

What do you think about an order ATV do I need a thermostat

crystal clear

Thank you much a mechanic told me to take it out and it will only cost $50.00 for him thank you💰💯✊💯💸

I have to add my input on this and I believe that running without a thermostat is a bad idea because number one the water is just going to pass through the engine to quickly without absorbing the heat like it’s meant to in other words it can create hotspots in the cylinder head without reflecting on the overall coolant temperature so in my opinion it is a bad idea to run without a thermostat or some sort of Restriction at the minimum. Also it is a bad idea to block off bypass ports because those are needed for correct thermostat operation to have some water circulation while the thermostat is closed Removing thermostat may allow the engine to run slightly cooler but that all depends on the cooling capacity of the radiator let’s say for instance do you normally run a 190 thermostat and your car runs at 210° well removing thermostat isn’t going to change anything it’s just going to take longer to warm up but it’s still going to run at 210° but if you were able to add let’s say a second radiator you’re going to increase your cooling capacity so it could in theory run at I don’t know 160° but like the guy said thermostat allows you to run at only minimum temperature.

We’ll the thermostat also restricts flow so the coolant can absorb heat. If you have no thermostat the coolant won’t have enough time to absorb the heat from the engine and therefore on long drives you will overheat

What if my Civic is still over heating without thermostat and fans blowing

in tropical countries cold start is no big deal... running your engine without a thermostat is good.

My dad's 1992 Nissan pathfinder XE is not overheating and it doesn't have a thermostat either

could the thermostat cause to dont have ac. and make your fan stay on?

I tried this with an old car 70's old. with no thermostat it ran cooler for a while but when it got hotter it could not cool down. with the Thermostat 180 deg. it always stayed at 180. I believe without the thermostat the radiator didn't have enough time to cool the coolant in the system when it got to the 180 threshold. It just continued to get hotter. it did stay cool for a long time before it got bad. So i always run a thermostat

i just hope people read the comments and yes removing the thermostat can make it overheat like sitting in traffic with ac on i know because my truck just done this decided to replace thermostat now all is good. so 100 percent it can cause an overheat problem nothing is restricting flow long enough to get rid of the heat.

Why do they sell different temperature thermostats if it doesn't make a difference

Where can i buy one for my bk2 3.8 genesis coupe?? Definitely dont want it overheatin

Thanks for the video I don't have a thermostat and it's still overheating but at least we know it's not the thermostats problem talk soon

so if my 2001 toyota camry .that i replace three fan sensors and fan switch still no fan kick on so put on manual toggle on all the time now but still temperature getting hot. head gasket good fresh new coolant..and i took off thermostat. still getting hot. coolant is flowing ,i dont understand. can you help..before i have to take to shop..Thanks for videos..they help alot.

that entirely depends on the climate of your location, if you're driving in warm and tropical climate places then you dont really need the thermostat because the coolant temperature is constantly fix on the optimal running temp level, but if you're driving in colder climate and snow then you definitely need the thermostat in order for the coolant to melt in radiator before going in to engine...

I just added a fan Stroud and it instantly fix the problem 😂

Replaced the thermostat, two different ones. Still was boiling in the reservoir. It runs fine with no thermostat. What could it be?

So much confidence, for so much misinformation..

but it work with my e30 m40, suddenly overheat just like a broken thermostat or weak viscos, change new radiator, new water pump, new viscos and new electric fan, but still overheat, never thought its because im not using thermostat but when i put a new thermostat in it its all good just like that, still dont get it till now

So I had my radiator replaced after that start to over heat thought maybe I need a new thermostat bought a new one and I still can’t get right temperature with new thermostat or get to stay at 210 so I went an head an took the thermostat out and getting water flow to block now temperature is back to normal but with new thermostat still over heating any ideas ???