2017-2018 Elantra 2.0L Thermostat Issues

[Blinker]

If the OEM thermostat is 212 degrees, and the listed ones are 190 and 192, I'm not sure how that is an exact replacement. I suppose using 85 octane in a ZR1 Corvette is "acceptable" also, but it doesn't mean there won't be a sacrifice of some sort (performance, knock).

I'll agree OEM would be best.

I reached out to two local dealers and both confirmed there is no recall for my vehicle regarding coolant temperature or thermostat issues. There is an "ECM update" for misfiring/knock though, which is interesting considering I don't have a Theta II. I was advised to wait for a colder day to more easily duplicate the issue. If they can't definitively prove an issue, they can't be reimbursed by Hyundai for warranty parts and labor. So to allow things to go smoother, "help us help you" and wait for a cold day. I'll report back once I have an update. Thanks everyone for your input (yes, even Imp4. I wasn't trying to sound condescending or combative, and I appreciate your input).

There is a TSB on the heater issue. Hopefully they witness it malfunctioning so they can fix it for you. The engine misfire ECM update is different than the Theta II debacle. The 2017-2019 Elantras have had a history of random misfires and coil pack issues so it’s a valid ECM update.

 

[OilMagnate]

I couldn't get past the part that said "started car with heat/blower off" and then getting back in 10-12 minutes later and cranking the defrost. Sounds like an excellent way to crack a windshield.

Why would I turn on the heater when the engine, coolant, and heater core is ice cold? Knowing what I know now I'm definitely glad I didn't or it may have never warmed up at all. Do you get in your car and immediately start driving with a fogged windshield and the 'heat' blowing ice cold in your face? I'll assume the answer is no.

And how exactly would that crack a windshield? Enlighten me. I didn't say I went outside with a boiling pot of water to pour onto it...

 

[OilMagnate]

There is a TSB on the heater issue. Hopefully they witness it malfunctioning so they can fix it for you. The engine misfire ECM update is different than the Theta II debacle. The 2017-2019 Elantras have had a history of random misfires and coil pack issues so it’s a valid ECM update.

Good to know. Thanks for the info.

 

[92saturnsl2]

Why would I turn on the heater when the engine, coolant, and heater core is ice cold? Knowing what I know now I'm definitely glad I didn't or it may have never warmed up at all. Do you get in your car and immediately start driving with a fogged windshield and the 'heat' blowing ice cold in your face? I'll assume the answer is no.

And how exactly would that crack a windshield? Enlighten me. I didn't say I went outside with a boiling pot of water to pour onto it...

Having grown up & learned how to drive in a northern climate, I was always taught to turn the defroster on with the car, so that the heat output directed at the windshield starts cool and the temperature change to hot is gradual (as the engine warms up). Have heard enough horror stories of very cold glass + hot defroster = cracked glass to believe it's not some old wives tale. Obviously if it's just cabin heat, it makes no difference.

Perhaps in OK this isn't an issue. Or just different strokes for different folks. Apologies for the thread jack, wasn't intended to be insulting.

 

[OilMagnate]

Having grown up & learned how to drive in a northern climate, I was always taught to turn the defroster on with the car, so that the heat output directed at the windshield starts cool and the temperature change to hot is gradual (as the engine warms up). Have heard enough horror stories of very cold glass + hot defroster = cracked glass to believe it's not some old wives tale. Obviously if it's just cabin heat, it makes no difference.

Perhaps in OK this isn't an issue. Or just different strokes for different folks. Apologies for the thread jack, wasn't intended to be insulting.

Hmm. I've never heard of this. Theoretically it makes sense, but I've never heard of this cracking a windshield. Then again, I've almost always lived in a southern climate. No worries, I didn't think you were thread jacking, and didn't think it was insulting at all. It was just such a strange statement and concept to me that I didn't know how else to ask the question other than blunt and direct. Maybe a bit overly so. Apologies if I seemed insulting.