i have changed the thermostat and after driving for a few miles steam started coming out of the thermostat housing as the temp gauge went into the red. any pointers as to where i have gone wrong and how to repair.

thanks

 

Hello Charlie,
I'm not absolutely positive since I am new to Hyundai vehicles, but some of the things you might check.
Are you sure the thermostat is installed exactly as it was when you removed the old one?
If your engine has an electric cooling fan is it coming on when the engine starts getting past the normal temp range?
Did you make sure to get all the air out of the cooling system when you refilled it?
Again , some engines will not tolerate overheating at all and will develop a head gasket problem. I'm not sure if Hyundai engines tolerate this type problem.
Not knowing the mileage, but has the water pump been checked out?
Last but not least did you replace the lost coolant with at least a 50/50 mixture of anti-freeze and water?

 

It may be a number things such as a coolant leak and a damaged radiator.

 

Steam coming out of the thermostat housing means it may not have been put back on correctly.
Could be losing coolant through that leak. No coolant could cause the system to overheat.
Re-do the thermostat housing with new gasket.
Re-fill the radiator with coolant. Run engine and keep filling radiator.
When the thermostat opens, should be able to fill the rest of the system with coolant.
Put the cap back on the radiator and watch to see if cooling fan turn on.
If it does then go for a test drive
If not then troubleshoot the cooling fan


Edit: Yeah it is possible the overheating could cause head gasket problems

 

Have you tried replacing the rad cap? It may be a small piece or part of the cooling system, but it has an important role.

 

Verify again that the thermostat was installed properly and in the right direction. The air bleed valve, if applicable, should be positioned upward, and the thermostat should be oriented correctly.