Stay Calm & Pull Over Safely. Every car or truck i have owned runs hotter on the highway. I have replaced all the seals and hoses, and … And even on the open road, coolant never has a chance to park in the radiator long enough to give up heat energy to the atmosphere. It doesn't. On the highway, the car may reach temperature, opening the thermostat. Follow these steps to handle and overheating engine if you car, truck, van or suv. In fact big ships … If you face the overheating problem while driving, first stop the car, turn the heater on full blast so that the heat is pulled out from the coolant to the ambient air of the car. Next, turn off the AC. If this problem happens while the engine is cold, it may be part of the engine's design. I noticed that the engine runs hotter when I am in traffic or idlying. I only have a stock gauge, but its usually only about 1/4 of the way towards hot. car running hot on freeway. Again, this is false, most hybrids have EPA mile per gallon city estimates in the 30's to 50's best case. ... have an air pocket in the system that can't escape and therefore causing hot spots inside the coolant passages and a hotter running engine. Idle the engine for a couple of minutes and then finally turn off the engine. If your car seems to be revved up to a higher-than-normal RPM while idling, it's not necessarily a problem. Help is at hand × The car runs hotter on the interstate from the ecu/O2 sensor leaning the motor out to get better gas millage. Richard Rowe has been writing professionally since 2007, specializing in automotive topics. Ok, i see I my have used a couple of $5 words when some 10 cent ones would have been better. Rowe studied engineering, philosophy and American literature at … The needle normally runs right in the middle of gauge and now runs 2/3 to 3/4 up gauge. Are you in Thailand and feeling low? Then I purchased a new 2nd oem thermostat and it runs hot again about 3/4 way up gauge. I pulled the first oem thermostat and drilled 2 small holes, which helped and it only ran slightly hotter than normal. Hagerty Drivers Club member Paul V. Romero writes: My ’67 Mustang with its original 289 V-8 runs hotter than normal during the summer months.I live in Santa Fe, New Mexico, where it doesn’t get much above 90 degrees. Car is rough until approx 30mph. My car runs cool almost all the time. Think about what happens when you stick your hand, or your face, out the window of a moving car, and it’s easy to see how this works. Car was OK for a day or two, then same problem! Hybrid cars get over 70 MPG! ... id deff flush radiator add radiator relief.alot of fans lower at highway which you allreddy know,i liked the cardboard test myself.those fans are tempermental that way . Because of this cooling fins can become plugged stopping air flow through the radiator core causing the engine to overheat. Whether you’re on the freeway, highway, or busy street stay calm and pull over if you’re overheating. Oil temp is a direct reflection of load. It stays cool while driving, even for long distances. I made sure I put the cap/rotor on in the same position, checked all the plugs for correct gap, now I'm at a loss. Bartl, I get that. Car runs fine on the highway now, I hit 80mph to test it out with no problems. I've already put $500 into it so far this year (more then the KBB value). This will only add insult to injury! The biggest cause of this is a faulty thermostat that is stuck closed. Sounds to me like, there is air in the system or the radiator is on its last leg. Yes it continues to get hotter and boils over coolant tank, if you don't shut engine down it get hotter. If you are worried about the thing running a little hotter, put like a 170 thermo in it. After all, if your car is baking in the sun at 90 to 100 degrees and the engine hasn’t even been turned … You might want to step out of the car when doing this. My 302 runs hotter on one side, but i have spark on all plugs. on highway it's ok. 1992 Pontiac Grand Am. You can't have things both ways. Car runs hot while stopping in traffic or when parked. The difference between the primary radiator and the heater core is that air going through the primary radiator comes in through the front grille and exits into the engine bay, while air passing through the core comes in through intake ducts in … My commute to work is about 4 miles through LA. 1. I will take you though the steps to figure out what is wrong so you can fix it yourself. When you are driving around town you horsepower loads are less-stop-n-go, etc. Let your car cool for a minimum of 10 minutes. Does your A/C work fine when you first start the car but then fail after a while, especially on hotter days? But I know that a simple water flush with the rad in the car would never have got it cleared out. Check to make sure nothing is blocking your front bumper openings. Open the hood of your car to allow the heat to clear out quickly. Once your car has cooled off, turn the ignition to its first position (don’t start the engine). On the highway you need 40-50hp or so just to keep moving. Personally I’ve had very good luck using the shop line solvent, I just pour a gallon of the solvent to about half a tank of gasoline, then I go on a highway and drive the car at the maximum speed limit, for about half an hour or … Pull over to the side of the road, park your car and turn off the engine as soon as possible. After that second rodding-out and flush, the car was OK and never had the problem again. any suggestions? Never operate your engine without a thermostat! My car runs hot on highway and pretty hot in town? If your car seems to overheat in city traffic but not on the highway. The most common symptom of a failed thermostat is overheating at highway speeds. I mean it just as when running without a thermostat can cause a car to run hotter. In a closed system there is always "x" amount of coolant absorbing heat and "y" amount of coolant shedding heat. So things just get hotter and hotter til you're forced to shut it down. more airflow over the radiator keeps it cool on the highway, in town more sitting in traffic and lower speeds let it run hotter. That way it will give you a little extra time in stop and go traffic, and will still be hot enough running down the road. I am sure it will drive a lot better. Symptoms are an engine that runs hotter than normal, a temperature gauge that indicates hotter temperatures during high speed (highway) operation, inconsistent heat coming from your heater, and overflowing when the engine reaches normal operating temperature or after a hot shut down. When coolant never has a chance to give up heat via the radiator, it gets hotter and hotter, especially if you’re stuck in traffic. With summer on its way, temperatures are rising – and the risk of your car overheating is on an upward trend as well. Each cycle the water makes is hotter and hotter until it exceeds the capacity to sufficiently remove heat. My car used to always runs about about 190 and now it goes up to about 230 before the fans kick in. When your car is moving, air is forced through the radiator, which helps it extract more heat. Why does my Car only Overheat on the Highway? How this system works: Your coolant system is designed to help remove heat from the engine during operation. The radiator still works when your car isn’t moving, but it isn’t as efficient. A car having sat that long will really benefit from a good run to chase all the carbon out. All I want is for the car to last till the end of November, without putting any more money into it. 6 Most Common Reasons Your Car Overheats. When you hit highway speeds, however, your engine needs a lot of coolant flowing through to keep it cool. We re-did the cleaning, finding lots more crud in the tubes (must have been in the engine). Car idles really rough, kind of sounds cool like I have a high lift cam but very low idle and very rough. Your car's heater is kind of like a miniature radiator. I checked the fans and they are working. Now the water is also going through the upper and lower radiator hoses and radiator. 98 Integra Type R - Running Log Serious damage can occur if your engine is overheating. Sign in to reply. Car runs hotter on Highway F30 / F31 / F32 / F33 / F34 / F36 (2012 - current) Need someone to talk to? A damaged radiator, low coolant, faulty radiator cap, or obstructed radiator can also be at fault. A new breed of "plug-in" hybrids can improve gas mileage but they also have a gasoline engine to power the car when the battery runs out. Because your car hugs the road it is constantly being bombarded with debris such as dirt, hair, leaves, trash and bugs to name a few. ... 1969 Z11 Pace Car - L48 350cid/300hp - 4 Speed Muncie 12 bolt rear. I let the car idle until the fans turned on and it was about 40 degrees hotter then it used to have to be. If there is a primary reason for an engine overheating for both of these reasons, it would be that the radiator is not able to properly lower the coolant temperature. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. How does the water flowing too fast cause the engine to overheat? At that point, I would flush out the system and refill it with fresh, clean coolant. ... Get on the highway and drive it long periods at around 2500-3000 rpm. 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