Questionthank you for the answer...here is further info you requested
2004 Hyundai Tiburon V-6 GT
We replaced thermostat thinking it was bad but it still gets hot. Fans do come on with AC but not when AC is off.
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The text above is a follow-up to ...
-----Question-----
Fans run when car is sitting and A/C is on.
When at a stop or very slow and A/C is not on, fans will not come on and temp rises to the extreme and I have to stop car - running HOT.
I just replaced thermostat...that didnt work. Got any answers? Thanks so much!!!!
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Depending on the year and model of your car, the fans will be controlled either by the engine control module (ECM) or a series of relays which run off a switch in the radiator.
You're going to need to be interested in a few things:
1. Coolant should be full. If it isn't, you need to investigate why not.
2. Coolant should circulate when the engine reaches operating temperature. If it doesn't, you'll need to find the blockage. It's possible the radiator is clogged or that the thermostat was installed incorrectly.
3. You'll want to check the fan control system. The methodology for this will vary depending on what control system your particular vehicle has.
Please follow up with the year and model of your vehicle as well as the engine size if it's a Santa Fe or Sonata. With that information, I can probably give you much more specific information.
AnswerFirst, if you've got less than 60,000 miles (in the U.S.), I'd recommend taking it to the dealer and let them sort it out. There's not much that would cause overheating that won't be covered under the warranty.
The fans on your vehicle are controlled by the ECM based on the readings it gets from the coolant temperature sensor. If your check engine lamp is on, you should investigate the cause. Doing a good diagnosis, however, will require a scan tool capable of reading the coolant temperature sensor readings. The idea is to monitor what the computer is seeing and determine whether it's receiving incorrect information, not turning on the fans when it should, or whether there's some problem in the fan control circuits used by the ECM.
You might also have a peek inside the radiator. If you see a grayish substance on top of the radiator fins, it's likely that the radiator tank has melted from the overheathing and is clogging the passages in the radiator. When this occurs, the filler neck is typically damaged as well. The cap sealing surface in the filler neck should be nice and smooth.
