Hyundai Elantra Thermostat Replace - Code P0128

[@ooscgt]

Nice video. So, is this an electronically controlled thermostat? Can you also tell us if there is a special procedure to bleed the system? Thanks!

[@Ah_Duuu_Ma]

I did not need to bleed it. The cooling system will bleed itself from the coolant reservoir tank. The small coolant hose will bleed all the air out itself. Just top off the coolant to the max level.

[@caitlynbegay9751]

Nice video! I changed the thermostat on 2017 Elantra w a 2.0 and it’s still overheating- I was wondering if you could help out on location on coolant temp sensor on! Again enjoyed the video

[@Ah_Duuu_Ma]

@@caitlynbegay9751 Follow the radiator upper hose going into the engine side (next to the upper hose). Its a gold looking sensor.

[@caitlynbegay9751]

@@Ah_Duuu_Ma thank you so much bro, helps alot!

[@ezzatalokapi1709]

I live in a very hot area. I canceled the sensor and now the temperature is normal. Is this correct?

[@raidmustafa143]

My question is how hot is the engine Elantra 2018 mpi 2.0

[@onlyme8870]

Anyone replace the thermostat inside the housing? Or does it have to be the whole assembly replaced? I tried to use a supposed genuine thermostat. But I get the code still.

[@Ah_Duuu_Ma]

Its a whole assembly for the thermostat together with the housing. If the code doesnt clear, check water pump and engine coolant temp.

[@FurqaanQ]

Bro...i have a 2017 Elantra. While im parked the temperature guage shows normal temp ( needle in centre ) and heating works fine but when i start driving the guage needle starts going towards cold and heat doesnt work at its best. No warning lights or anything on dash. This issue has been happening during winter. What should i do? I subscribed

[@Ah_Duuu_Ma]

If the temp gauge is going down when driving that is a bad thermostat, thermostat partially staying open when the engine is cooled to normal the levels. When you're traveling down the road, there's a greater air flow through the radiator. This means there's greater cooling capacity (increase air = increased cooling ability). If the thermostat is working correctly, it will allow hot coolant from engine going to the radiator to cool down and cooler coolant from radiator will flow into engine to MAINTAIN a normal temperature. If temp is going down when you driving, this means thermostat is allowing too much coolant from radiator into engine and allowing the temps to decrease, which is not a good thing. It won't hurt the engine but it does hurt the fuel efficiency. Recommending you replace the thermostat and coolant temp sensor. Buy oem parts. Good luck to you.

[@FurqaanQ]

@Ah_Duuu_Ma My friend, thanks a MILLION for explaining this issue so professionally. You have nooo idea how stressed I've been lately due to this problem. I'm a full time driver and I've learnt a lot of things by being on the road most of the time, but this was my first encounter with a bad thermostat I guess. Love you my brother. I'll watch your videos to learn more about cars. Thanks again for replying and sharing your expertise.

[@onlyme8870]

Hi I replaced thermostat 2x because of this code. Now I'm finding at random times coolant in the catch pan under the engine bay. 2018 Elantra 2.0l so I bleed the system after I add coolant. But not finding where it's coming from. I was able to get the 2st thermostat replaced under warranty but the 2nd one unfortunately they said isn't covered only the 1st. Kinda sketchy but is what it is. But if anyone has some extra input feel free to share. P0138 is the only code and it only shows pending never in red. I've done the reset incase it was an anomaly but it comes back sometimes a month later.

[@raidmustafa143]

Hello, I have an Elantra 2018, the thermostat crashed, I changed it, but with a mechanical piece measuring 82 Celsius, but I feel there is a waste of fuel, is this possible, please explain with thanks

[@Ah_Duuu_Ma]

@@raidmustafa143 82 Celsius = 180 Fahrenheit. That’s normal temp. Anything from 180 to 220 Fahrenheit is normal temp. Anything going higher than 220 is going up to overheat. When radiator fan kicks in, temp drop.

[@kenwalter2697]

is this the same engine for a 2013 elantra gls 1.8l

[@Ah_Duuu_Ma]

If you have the same code, yes.

[@kishetamara2851]

I thought you supposed to put back the black piece that was on old thermostat?

[@Ah_Duuu_Ma]

The black piece is 1 way fit. Cant go back in after remove. Thought the new thermostat comes with it, but its sold separately. The black piece doesn’t affect anything. Cost around extra $40 for the piece.

[@mrgarner16]

This is what I came here to ask

[@mrgarner16]

​@@Ah_Duuu_Mado you know what the black piece is called if we do want to install it? Thank you

[@kishetamara2851]

@@mrgarner16I removed from old thermostat and installed on new thermostat works fine no problems. You don’t need to get rid of it if you don’t damaged the clamp. It is very important for thermostats It is called Lower Radiator Hose

[@mrgarner16]

@@kishetamara2851 oh ok thank you for the help. Is there a technique for getting it off? I saw on another video someone else had trouble getting it off, and broke it. I'm going to change the thermostat in the morning

[@JS-te4gz]

Can be temp sensor too ....

[@PsychHacks]

You need to refilm this. That loud beeping noise makes this video unwatchable.