Engine temperature going up & down, bad thermosta?

[Rohan]

Originally Posted By: Vikas

There is absolutely no effin way the temperature drops 50 degrees in 5 seconds when the fan(s) come on especially if the car is stationary. Physics does NOT allow that. I take it back. If the thermostat stays stuck until it reached 230 and then suddenly open up, I could see temperature dropping very fast because now the cold water and the very hot water will mix. You can verify this theory by feeling the hoses and see when they transition from being soft cold to hard hot. That tells you that the thermostat has now opened up. Looks like you should just get a new OEM thermostat from the dealer if you are going to do the job again. Is dash board gauge mirroring the numbers you are seeing on the scanner? On the related topic, I need to know the steps involved in replacing the thermostat. If you don't mind, can you take some picture during the procedure? I am presuming you replaced the FPR regulator and that problem has been now taken care of?

Hi Vikas, Yes I can feel hoses becoming soft to harder and yes dashboard guage is mirtoring the number I see on my scanner. Maybe you are right there is no way is going down in 5 second and I'm going to go ahead and replace the thermostat with the OEM from the Honda because I hate to crank up the car every time and see temperature gauge going up to 230F. I will try my best to take a picture from my iPhone. The problem has been taken care on FPR and engine is running better than before expect overheating issue.

 

[Rohan]

@SHOZ & @cjcride radiator is full with coolant.

 

[Vikas]

Do you need to take off that water pipe thingy which contains the thermostat before changing it?

 

[Rohan]

Originally Posted By: Vikas

Do you need to take off that water pipe thingy which contains the thermostat before changing it?

I don't understand your question. I posted a video of how to change the thermostat on the odyssey and that is not my video. https://youtu.be/BF8sCe0ULNE

 

[Rohan]

Originally Posted By: Vikas

Do you need to take off that water pipe thingy which contains the thermostat before changing it?

Are you talking about thermostat housing before the thermostat come out?

 

[Rohan]

I just remember that when the fan is coming on then fan is making the loud noise. Do I need to worry about this or just force on the thermostat for now?

 

[Vikas]

Fan should not be making that noise. Are the blades hitting the housing? You should be able to turn the fan by hand to feel if it rotates freely or not.

 

[Rohan]

I did not take out the thermostat because I was doing the bleeding process again. I got the right number it boiling at 225F at this point I have to put the cap back on but I didn't I rev the gas and I saw the fans coming on while it was boiling and coolant was throwing all over the place. If I did put the cap back on at 225F and not rev the gas at the idle then temperature will start rising up to 235F (then fans will come on at this degree).

 

[Rohan]

Originally Posted By: Vikas

Fan should not be making that noise. Are the blades hitting the housing? You should be able to turn the fan by hand to feel if it rotates freely or not.

let me check if the blades hitting the housing and yes fan is rotates freely.

 

[Rohan]

Is this normal? My overflow tank cap is becoming loose. As soon I tighten them down after that in short time it will become loose. I believe the cap on the overflow is stripped. Can overflow tank hold any pressure? if it don't then I don't have to rush to buy new overflow tank.

 

[tdpark]

Did you remember to turn on the rear heat? If you didn't you will not get all the air out.

 

[Rohan]

Originally Posted By: tdpark

Did you remember to turn on the rear heat? If you didn't you will not get all the air out.

I'm going to posted a video tomorrow on heat control settings and you can correct me if I did something wrong.

 

[Rohan]

I just thought about it that both fans supposed to come on before it start boiling, Correct? If I'm right then my fan is coming on AFTER it started boiling in 2-4 seconds fans will come on then coolant will spray all over the funnel then I have to shut down the car.

 

[Vikas]

Coolant *will* boil if you don't have the radiator cap on. Make sure radiator cap is in good condition, otherwise get a new one from the dealer. The reservoir tank is NOT pressurized. The reservoir cap *will* strip if you tighten it too much. Just tighten it enough and leave it alone. Only *one* fan will come on unless you have A/C on.

 

[Rohan]

Originally Posted By: Vikas

Coolant *will* boil if you don't have the radiator cap on. Make sure radiator cap is in good condition, otherwise get a new one from the dealer. The reservoir tank is NOT pressurized. The reservoir cap *will* strip if you tighten it too much. Just tighten it enough and leave it alone. Only *one* fan will come on unless you have A/C on.

I'm gonna do the radiator pressure test on the cap to see if it holding 15psi. I know you have a odyssey, do you know how to set the rear heater to MAX setting? Both fans is coming on so I need to turn off the A/C button that will show on the screen "A/C OFF". Right?

 

[Vikas]

Put the front dial on max red, full fan and thear rear on the full red too. the A/C button toggles A/C on and off

 

[Rohan]

Originally Posted By: Vikas

Put the front dial on max red, full fan and thear rear on the full red too. the A/C button toggles A/C on and off

I know how the front one work but I'm confused about the rear one. I thought fans setting need to be at Lowest setting? Front ; Turn knob all the way to 90 degrees and fan setting at low. Turn A/C off Rear; What is "RR" mean? Do I turn the knob where's show Red dots? And fan setting must be off or lowest setting? As soon I wake up I'm going to post a video of how my heater setting is.

 

[Vikas]

turn to the the biggest red dot. I don't think fan setting matter; I would leave it at high. RR means it is controlled by the rear seat occupant on top of the drivers's door instead of being controlled by the driver

 

[Rohan]

Originally Posted By: Vikas

turn to the the biggest red dot. I don't think fan setting matter; I would leave it at high. RR means it is controlled by the rear seat occupant on top of the drivers's door instead of being controlled by the driver

Okay Thank You Vikas and I'm going to try it again tomorrow. I just did the bleeding process again and i left that setting in the "off" position for the rear control setting. I wish I saw your post earlier. While i was bleeding the air out then at this time i did not turn off the car when it started to boil the coolant, I left it like that while I was holding the rpm at 1500 and both fan did came on, and at this point coolant start to flow into the radiator (I did this two time). I believe bleeding was not done properly on this car. I'm going to do the bleeding tomorrow again by leaving the rear control setting in "biggest dot".

 

[Vikas]

Biggest "RED" dot