Your car may be overheating for a variety of reasons. In this article we will look at some possible causes of a car overheating and a possible fix, whether easy or hard, for that particular situation. As usual before we dive into the diagnostics let’s look at why a car gets hot.
It may seem pretty obvious to you that a car’s engine gets hot because of the explosions going on inside. In the end, this is the truth, the burning fuel/air mixture is what creates the heat in an engine. Much of that heat gets pushed out with the exhaust gases but some of the heat’s energy soaks into the cylinder walls and heads before it is pushed out of the exhaust valves. The reality is, this heat is really what makes your engine move. The heat from the explosion of fuel and air cause the gases in the combustion chamber to expand rapidly. These expanding gases force the piston in your engine down which causes the connecting rod to push the crack shaft around which turns the flywheel and voila, your motor is running! This is why some people will call the internal combustion engine a “heat” engine. This also means that the more heat you can produce in a single explosion, the more the gases will expand, the harder the piston is pushed down and the more power your engine will make. Some engines do not create that much excess heat so there is very little worry of them overheating. For example, the engine in your lawnmower doesn’t have a radiator or coolant and yes it gets warm when you run it, but under normal operating conditions it will never overheat.
As internal combustion engine technology increased, combustion temperatures increased because higher combustion temperatures make an internal combustion engine more efficient and more powerful. As temperatures increased, new methods of keeping the engine materials from melting or being damaged were needed. First air-cooled engines were fitted with fins to help dissipate heat, then the water cooled engine was designed. Water can remove heat from a surface much more quickly than air because it is a better conductor of heat. Water cooling for engines allowed greater combustion temperatures and much more power and efficiency from smaller motors.
The engine in your vehicle is most likely a water cooled engine unless you have a vehicle from before the 1940s, or a very old Volkswagen or Porsche. The benefits of a water cooled system have already been explained and the only problem with it is that a malfunction can easily cause catastrophic damage to the engine. This is why it is extremely important to keep a watchful eye on the temperature gauge in your car and fix any overheating problems immediately.
Possible Causes of a Car Overheating:
- Lean Mixture of Advanced ignition timing: Modern cars are fitting with electronic fuel injection and spark control so this isn’t a concern on modern cars, but we thought we would mention this for our classic car enthusiasts. The result is the same if you do not have enough fuel mixed with your intake air charge, or if the spark fires too early. As a mist of fuel is injected into the combustion chamber it can actually help cool the intake air charge. If too little fuel is injected the air charge is not cooled enough and the mixture can begin to explode too early. Similarly, with more advanced timing, or too soon of a spark, the fuel/air mixture detonates too soon. This means much more of the heat from the explosion is transferred to the cylinder walls and combustion chamber rather than expelled with the exhaust gases causing your engine to overheat. Consider adjusting your carburetor to run richer, decreasing your initial timing advance, or changing your distributor weights and springs for less advance.
- Dirty Cooling System: As you drive your vehicle, the cooling system can become dirty or clogged from wear particles, corrosion products or other impurities in your coolant. Overtime and from the heat of normal operation these particles can cause scale to form on the inside of your engine or the radiator reducing heat transfer and making your cooling system insufficient for the needs of your engine. In this case, consider using BlueDevil Radiator Flush to clean your cooling system and return it to its normal heat transfer capacity. Get more information about BlueDevil Radiator Flush here.
- Low Coolant: The cooling system in your vehicle is designed to operate with a full charge of coolant. If your cooling system is low, there may not be enough coolant in your system to properly cool the engine. For example, if the radiator is half empty, the coolant only has half of the time it is supposed to have in the radiator so it will enter back into your engine at a higher temperature so it will not be able to cool your engine properly. Ensure you have proper coolant levels by checking the level in your overflow tank. If you have low coolant, consider adding BlueDevil Pour-N-Go to your radiator before topping it off with the manufactures recommended coolant. BlueDevil Pour-N-Go will seal any leaks you have in your cooling system ensuring a proper coolant level and no more leaks. Get more information about BlueDevil Pour-N-Go, click here.
Pick up any BlueDevil Product at our partnering local auto parts retailers:
- Bennett Auto Supply
- Pep Boys
- Car Quest Auto Parts
- Prime Automotive Warehouse
- Advance Auto Parts
- O’Reilly Auto Parts
- AutoZone
- NAPA
Picture courtesy of: northgeelongradiators.com.au
42 responses to "What Are The Possible Causes For My Car is Overheating?"
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Hey to whom this May concern I have added the blue devil in and it’s been working however today my car was over heating could you give me some suggestion on why my car is over heating?
Victor-
Defective fan switch, defective fan clutch, clogged or restricted cores, sediment deposits, systems jellied from antifreeze , or a faulty water pump could all be possible causes to lead to the vehicle overheating. You may want to have the vehicle further diagnosed so that you can pinpoint the problem.
2000 Buick Century. Leaking lots of coolant.Mechanic put blue devil gasket leak in it .He said there was a hairline crack in the head. No leaks but the only way my car does not over heat is if I have the A/C on or heater. What do you think the problem could be. I also had the water pump changed.
Dennis-
Thank you for asking about your Buick Century. Are you still noticing a loss of coolant? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s conditions and be able to make any appropriate recommendations.
Thank you!
-BDP
I had two cracked heads on a ’96 Dodge 1500 5.9 V8. I used Blue Devil in an attempt to ‘fix’ the problem. It seemed to help but it didn’t fix the overheating problem. I’ve since replaced the heads and a few other things to no avail. Could the Blue Devil have coated the inside of the block to the point that it is preventing the transfer of heat to the water?
Harold-
The BlueDevil Head Gasket Sealer will not coat the inside of the block nor effect the transfer of heat to the water. There are a number of different reasons that can cause an engine to overheat; they are not always related to the head gasket.
We recommend that you have a certified mechanic diagnose the vehicle so that you can better pinpoint the cause of the overheat.
Please contact us at 888-863-0426 in regards to the BlueDevil that was already used.
Thanks,
-BDP
hi.
i was driving my car, parked then turned off my igniyion. there was a grumbling noise and.then poof slight cloud a smoke. it was overheated. i took it to my mechanic and he said it melted something and i had to pay 600$ to het the ebtire cooling system fuxed, fans wires ect.. since then i drove my car about 2 days after on my way to work it was overheating even with my heat on i kept pulling over witch seemed to work but then i went up a small hill and.again it was overheating and again the grumbling noise but this time it was a huge thick cloud of smoke. i sat for 20min the car seemed fine started easy and i went home. a few days went by and today i was driving.and it was fine then i sat idle for about 3 min and it started to overheat again. im sumwhat pissed off because i spent 600$ thinkin they fixed it but yet my car is still overheating.and.i dont.understand why. if it was a gasket, wouldnt they have been.abke to spot.it being they did.a check over before they performed.the work?? help me please.
Sarah,
Thanks for your question about your car overheating. Without knowing what your mechanic replaced, it is difficult to tell where you problem is coming from. It could be something as severe as a blown head gasket or something as simple as installing a new thermostat. At this point, it sounds like your best course of action would be to go back to the mechanic and see if they will repair your problem under warranty because they didn’t fix the problem the first time.
Hi there, I have a 2000 taurus V6 3.0 that overheat, the fans are perfect, oil is ok with no mixing oil with cooling system, no leaks and we just replace the thermostat.
My mechanics sait is the head gaskets because the pressure go high and start overheating, I purchase the blue devil white container were no need to do anything but pour on cold temperature. Is this goin to work or should do the $600 fix.
Rafael-
Yes, we do recommend using the BlueDevil Head Gasket Sealer to help repair your Taurus.
Based on your description, it sounds like your vehicle may be getting combustion/exhaust gases blowing into the cooling system and creating pressure. To give yourself the best overall chance of BlueDevil working successfully, in addition to the directions, you should remove the spark plug from the cylinder with the leak; this will be the spark plug from the cylinder with a low compression reading. If you are not sure which one that is, you may pull all of the spark plugs and will sometimes notice one will have a white-crystal-like substance on it and/or may look dirty; this is the plug you should pull. Leave that plug out for the 50 minute idle in order to relieve the pressure from building up and thus allowing the product to seal properly.
Feel free to contact us with any questions.
Thank you!
-BDP
My 2007 Jeep Grand Cherokee recently began overheating, but only when the car is idling after it has been running for a long time. I have been told that I have air leaking in to my cooling system at the #5 cylinder and that I need to have the head gasket replaced. Estimated Cost $1685. Can I use the Blue Devil pour and go?
Chip-
Yes, you can use the BlueDevil Pour-N-Go if the Jeep has a 6-cylinder engine. If it is a V8, we recommend using the BlueDevil Head Gasket Sealer (32 oz yellow label).
Based on your description, it sounds like your vehicle may be getting combustion/exhaust gases blowing into the cooling system and creating pressure. To give yourself the best overall chance of BlueDevil working successfully, in addition to the directions, you should remove the spark plug from the cylinder with the leak; this will be the spark plug from the cylinder with a low compression reading. If you are not sure which one that is, you may pull all of the spark plugs and will sometimes notice one will have a white-crystal-like substance on it and/or may look dirty; this is the plug you should pull. Leave that plug out for the 50 minute idle in order to relieve the pressure from building up and thus allowing the product to seal properly. Feel free to contact our technical support line 888-863-0426 with any other questions.
Thank you!
-BDP
Water is mixing with my oil I was told i have a cracked head i also see white smoke and it shuts off when I switch it in gear do you recommend your product??
Shamika-
Yes, we recommend using the BlueDevil Head Gasket Sealer. For best results you will want to change the engine oil before and after the BlueDevil process.
Thank You!
-BDP
hi I have a 2005 Chevy equinox just had plug and wires put but been had to put antifreeze in it like every other day. put thermstace on water pump just put a heatcore on it ran hot today now he say it my 6 cylinder intake now I need a motor what should I do
I have a 95 ford mustang srs V6 3.8L engine. On a long drive home with no cell phone and my 8 year old daughter in the car, with only miles of acreage of cows and oil fields my car puffed a nice little white plume of smoke from the exhaust and suddenly began to overheat. I had no other choice but to carefully continue our drive. After a while it started making a lovely sound, but we never red lined, it didn’t continually smoke, until we hit a hill and just couldn’t move anymore. Thick white smoke filled our area, and was pouring from the hood. My husband replaced the belt which had thrown, got it home the rest of the way, then replaced upper and lower radiator hoses, and the radiator. There is no more lovely sound that I can detect, and the smoke has dwindled, but she is still overheating. Could it be the waterpump, or am I in serious problems with a blown head gasket?
Charlotte-
Thank you for asking about your Ford Mustang. White smoke coming from the exhaust pipe is a tell-tale sign of a blown head gasket. If the water pump was faulty, it’s possible that you weren’t getting proper circulation in the cooing system, causing the vehicle to overheat and the head gasket to blow. You may want to check your service records to see when the water pump was last replaced, as it may be time for a water pump replacement. Also, you may want to check if your coolant is at the proper level, as the dwindling in smoke may just be from having low coolant. Once you have done that, you would be a good candidate for the BlueDevil Head Gasket Sealer. Feel free to contact our technical support team at 888-863-0426 with any other questions.
Thank you!
-BDP
I don’t know if you can help me but I have a motorcycle issue my motorcycle which is a 1997 GSXR keeps overheating I’m told that newer ones because they’re fuel injected have a less chance of overheating I was also told that because the bike has 33000 miles on it that may be the radiator is clogged and needs to be flushed and that I should remove the thermostat and then put in a manual switch for the fan so that I could turn it on when I see it overheating do you think these are good ideas
David,
Thanks for your question about your GSXR. Your bike could be overheating due to running lean so you may consider having your carbs cleaned or rebuilt. Usually, carburated bikes run a little rich for safety, but if they are clogged it could cause a lean condition and an overheat. You do have a lot of miles for a sport bike so it is probably not a bad idea to flush the radiator and add new coolant. That is also a good time to replace the thermostat as they are inexpensive and the cooling system is already empty. We would recommend trying all those things before putting the fan on a switch. If you do decide to add a manual switch to your cooling fan, make sure you wire it in such a way that it still comes on automatically when the bike gets too warm.
Thanks again for your question!
-BD Auto Pro
I have a 98 Chrysler concorde 3.2L 6 cylinder with blown head gasket. It starts to overheat when driving, the mechanic said it was blowing antifreeze out of the exhaust pipe when driving, I asked him about Blue Devil product, and he said that the leak was too bad and I could clog up my radiator and my heater coil. What should I do please help!
Travis-
Thank you for asking about your Chrysler Concorde. As long as the vehicle will maintain idle for a full 50 minutes, and you are not losing more than about a quart of water/coolant during that 50 minutes, you would be a great candidate for the BlueDevil Head Gasket Sealer (http://store.gobdp.com/head-gasket-sealer-38386/). Feel free to contact our technical support line at 888-863-0426 with any other questions.
Thank you!
-BDP
I have a 200 Cadillac deville dhs 8 cylinder northstar. I have had the blue devil sealer put in the big bottle they only used half I have had my thermostat, water pump, temp senor, and my spark plugs changed and my car is still running hot, I am at a lost and have spent a lot of money. I need to know what can I do because I seriously need to fix my car I need my car at the moment I have no more money to to buy another. Please help. Thank you
April-
Thank you for asking about your Cadillac Deville. Please contact our technical support line at 888-863-0426 so that we may get a better understanding of the vehicle’s condition and be able to make any appropriate recommendations.
Thank you!
-BDP
Hi. I have a 04 Chevy Impala. I have replaced the radiator due to a leak but before that I used radiator stop leak. It worked for awhile. Then I had to replace the radiator and both hoses. The top hose kept popping off. Then I replaced the water pump and thermostat. Still running hot. Flushed and bleed the radiator. While flushing the water hose kept popping out like there was a blockage somewhere but water was still flushing out of the radiator. Still running hot. Finally took it to the shop the man said that it was a blown head gasket, due to the white smoke. Can I use BlueDevil Head Gasket Sealer, or is it to late? Could the radiator stop leak be stuck in the engine somewhere? Help please!! Thank you.
Anita-
Thank you for asking about your Chevy Impala. Did the mechanic run any tests to see if the system was clogged? Based on your description, it is possible that you are getting combustion/exhaust gases pumping back into the cooling system. You or your mechanic can use a “Block Dye Tester” to confirm whether or not that is the case.
BlueDevil Head Gasket Sealer will still work if your vehicle is getting combustion/exhaust gases blowing into the cooling system and creating pressure. To give yourself the best overall chance of BlueDevil working successfully, in addition to the directions, you should remove the spark plug from the cylinder with the leak; this will be the spark plug from the cylinder with the low compression reading. If you are not sure which one that is, you may pull all of the spark plugs and will notice one will have a white-crystal-like substance on it and/or may look dirty; this is the plug you should pull. Leave that plug out for the 50 minute idle in order to relieve the pressure from building up and thus allowing the product to seal properly. Be sure to follow the guidelines for the proper amount to use based on the size of your cooling system.
Thank you!
-BDP
I also have a Impala with similar problems I poured to seal and it worked just remember to follow the instructions
Got a Pontiac sunfire 2.2 litre. The antifreeze is obviously leaking down from the head in 2 separate spots in the front and possibly a spot in the back. I see where you tell ALMOST everyone to remove their plugs and run engine PRIOR to using your BLUE DEVIL?
DO I REMOVE 3 PLUGS prior to blue devil?
David-
Thank you for asking about your Pontiac Sunfire. The engine would not be able to run with more than one spark plug removed. Also, removing the spark plug from the affected cylinder is only a recommendation we make when combustion/exhaust gases are pumping into the cooling system.
How quickly are you losing antifreeze? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.
Thank you!
-BDP
I recently used blue devil head gasket seal to stop a freeze plug Leak I Manage to stop the leak but now the car is overheating Took it to the mechanic thermostat radiator and fan are good what can be causing The problem
David-
That is excellent! We are happy to hear of the success you have had with the BlueDevil Head Gasket Sealer. Unfortunately, a vehicle overheat for a number of different reasons. If you had pressure building up in the cooling system prior to using BlueDevil, you may need to bleed the system to get rid of any potential air pockets. Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.
Thank you!
-BDP
A friend of mine helped me with my 89 Toyota 3.0 6cyl,, but we didn’t do it right, it was so difficult for me to get to the thermostat but I managed, but I put a new one in instead of leaving it out to use the blue devil,,nor did we flush the radiator,, uhg!! It’s temp is now normal, but should I redo the whole process over? Sincerely blown head gaskets and patients, I previously owned a Ford exsplorer,,
Diane-
Thank you for asking about your Toyota. Are you still noticing a loss of water/coolant? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.
Thank you!
-BDP
I have a 96 Cadillac Eldorado and I’ve replaced the radiator, water pump, lower radiator hose, and thermostat with brand new parts. My car is still running hot I was told it’s the freeze plugs and I brought the blue devil yellow bottle. My car still runs hot I followed the directions and I can smell the blue devil. I add coolant and water. What did I do wrong.
Anea-
Thank you for asking about your Cadillac Eldorado. How quickly is the vehicle running hot? Did you notice any improvement after applying the BlueDevil Head Gasket Sealer? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.
Thank you!
-BDP
My car was over heating and every time the engine light came on it always says it’s the ECT so I replaced that and the thermostat and checked the water pump and every thing seems to be good flushed out the coolant and all my hoses, so I took it to a mechanic and he said my head gasket was cracked, so needless to say instead of paying 3500 dollars a friend told me about blue devil so I let my car sit overnight and in the morning took the thermostat off and drained the coolant as directed on the bottle and slowly poured a blue devil in the radiator as directed and let it idle for 1 hour turned it off and let it cool down and put the thermostat back on and flushed out the system again then added coolant and took it for a drive for about 20 mins the temperature goes up to 3/4 of the way then when i take my foot off the gas and coast the temp goes back down. and i’m loosing coolant that spits out the over flow valve. Please tell me what i should do next??? We have done everything correctly and still now luck!!!!!
there is no coolant mixed in with the oil either….. My oil is clean.
Wendy-
It sounds like you may be getting combustion/exhaust gases pumping back into the cooling system. You can use a “Block Dye Tester” to confirm whether or not that is the case.
BlueDevil Head Gasket Sealer will still work if your vehicle is getting combustion/exhaust gases blowing into the cooling system and creating pressure. To give yourself the best overall chance of BlueDevil working successfully, in addition to the directions, you should remove the spark plug from the cylinder with the leak; this will be the spark plug from the cylinder with the low compression reading. If you are not sure which one that is, you may pull all of the spark plugs and will notice one will have a white-crystal-like substance on it and/or may look dirty; this is the plug you should pull. Leave that plug out for the 50 minute idle in order to relieve the pressure from building up and thus allowing the product to seal properly. Be sure to follow the guidelines for the proper amount to use based on the size of your cooling system. Feel free to contact our technical support line at 888-863-0426 for further assistance.
Thank you!
-BDP
I used the blue devil radiator flush on my 58 ford today. The car wasn’t overheating before but I still wanted to flush the radiator. I ran the car for 10 min With the product and the car started to over heat and build pressure. Any suggestions or advice? Do you guys know why this would of happened?
Thanks
Jason-
Thank you for asking about your Ford. It’s possible that too much air was introduced into the system during your flush procedure, and it created an air pocket. If you haven’t done so already, try bleeding the system to remove the excess air and then refill with the appropriate amount of water/coolant.
Thank you!
-BDP
Hi there. I just applied the blue devil head gasket sealant to my ‘94 Mazda B4000 4.0L w/ manual transmission. I followed the instructions perfectly, and now I’m waiting for it to cool down to reinstall the thermostat. A concern I had during the 50min run time at idle was the temp needle got as high as 3/4 of full gage range a few times and the engine still steamed once I shut it off. My issue is disappearing coolant, most likely in the fuel system. It’s not in the oil luckily. But at the beginning of the idle process I had filled my radiator (which I just replaced last week) with water as directed and slowly poured the product inside then capped it. I fear the water level may have gone down too far during the idle process. If that’s the case, how reliable is blue devil?
Johnathan-
Thank you for asking about your Mazda. In order for the BlueDevil Head Gasket Sealer to be successful, the vehicle would need to be able to maintain idle for a full 50 minutes, without overheating or stalling out, and you shouldn’t be losing more than about a quart of water/coolant during the 50-minute run. If you are losing coolant too quickly, you may lose the product just as quickly, and may not have had the product in the system long enough in order to get the benefit of using it.
Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.
Thank you!
-BDP
My 2002 Silverado does not overheat, but I was losing coolant and filling it back up daily. This went on for 2 weeks, so I did not continue to refill daily. I have now been running my truck daily without refilling coolant and it is running at same temperature and not leaking. If I top off coolant it will begin leaking again. Which of your products should I use to stop the leak even though it has not overheated? I also do not have any oil/coolant mixing going on.
Thank you,
Brent
Brent-
Thank you for asking about your Chevy Silverado. Are you able to identify where the loss of coolant is coming from? Are you getting a low coolant indicator on the dashboard? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.
Thank you!
-BDP