Hello everybody hope you’re doing well. I own a 1997 Lexus LS400 with 240k miles and its been running like a dream the last few months. Recently, while driving hard to work I noticed my temperature gauge up 3/4 and when I opened my hood I noticed a bit of steam. I went in to work as usual and decided to drive back home, and noticed my Lexus wasn’t overheating this time. I figured it might be a faulty temperature sensor and replaced that, and was not overheating when driving hard, but I did notice a bit of steam still coming out. Fast forward a few days later, I drive the vehicle hard again and noticed that it began to overheat again, so I turn my heaters up and the temperature regulated itself. I let two of my technician coworkers know about this and they told me it was a blown head gasket, what conflicts me is that my coolant levels were normal when cold and I didn’t notice any oil mixture or smoke from the exhaust. I would appreciate a second opinion on here, thank you for taking a look.
The heater blowing warm instead of hot and the elevated reading on the temperature gauge is sure pointing to a leak in the head gasket.
Leaking combustion gasses tend to get trapped or "locked" in the heater core which restricts the flow of hot engine coolant flowing through the core resulting in the heater core not getting hot enough.
Do a combustion gas leak test on the cooling system
p.s: I wasn’t able to find the issue in FAQ for diagnosing overheating.
It's there.
Why are you downvoting us? Is there a problem?
Hello everyone, I currently have a 1997 lexus LS400 with 240k miles. Recently I have noticed my temperature gauge go up, most of the time I was driving harder than usual. When checking the coolant levels, it did not change whatsoever. I changed the coolant sensor, as well as the thermostat and did a coolant flush, and checked on it today and noticed it still kept overheating. I did notice that the car would overheat more when slowing down. The fan seems to be working fine, A/C works but the heater is blowing warm air instead of hot. Im really not sure what it might be so I would appreciate some input, thanks!
p.s: I wasn’t able to find the issue in FAQ for diagnosing overheating.
Do not double-please. It's clearly stated in the forum rules. Please go read them now.