Engine temperature?

Tiny
BLAKKMAGICK
  • MEMBER
  • 2019 HONDA ODYSSEY
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 148,762 MILES
Hello,

My vehicle listed above seemed to take a turn for the worse on vacation. We noticed the temperature indicator was peaking at high as if it was overheating. There were no symptoms prior to or while the needle was maxed out (not sure how long it was maxed out).

Because we were 8 hours from home, I found a mobile mechanic and replaced the thermostat and assumed the problem was solved. Well, when departing the next day and in drive thru the needle started to rise again. Turning the heat on, dropped the needle to normal position.

After adjusting the heat. We resumed traveling home and didn't have any issues. Upon returning home, I tried to burp the radiator thinking air was trapped in the system. Now, the A/C only works when in motion (no prior issues). System and the car is acting like it's going to eat again.

Any ideas on what it could be?
Sunday, June 8th, 2025 AT 6:38 PM

6 Replies

Tiny
CANNON1349
  • MECHANIC
  • 795 POSTS
Hello,

When you turn on the A/C, does the fan come on in the front of the car? And just to confirm, the car does not run hot while in motion, only when sitting? Also take note if the radiator fan comes on at the proper temperature. Usually when the temperature gauge is in the middle of its travel.

Please let us know,
William
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Sunday, June 8th, 2025 AT 7:23 PM
Tiny
BLAKKMAGICK
  • MEMBER
  • 4 POSTS
Thanks for the response. I didn't notice the fan being on in the front. Yes, the car doesn't run hot when in motion unless moving really slow after the car has been running for a while. Like in a parking lot or drive thru for example. I've let the car run for 30+ minutes tonight and overheating has not been an issue but its a lot cooler night time vs day. Additionally, the fan has not kicked on either.
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Sunday, June 8th, 2025 AT 9:30 PM
Tiny
CANNON1349
  • MECHANIC
  • 795 POSTS
Hello, if the fans are not turning on, that is an issue. I will attach a photo of the relay locations in the fuse box under the hood. You can swap the relays with one like it to see if the fan turns on. Just make sure the relay you take is not used for something important.

Let me know,
William
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Monday, June 9th, 2025 AT 6:12 AM
Tiny
BLAKKMAGICK
  • MEMBER
  • 4 POSTS
Sorry for the delay. Fuses were good and fan seem to kick on. Now I have a P4020 code and the a/c isn't working. Must be time to throw the entire car away ( kidding. Beyond frustrated)
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Wednesday, June 11th, 2025 AT 11:30 AM
Tiny
CANNON1349
  • MECHANIC
  • 795 POSTS
Hi, if the fan kicks on when turning on the A/C that's great. However does the other fan turn on when the engine gets up to temperature? P0420 is low catalytic converter efficiency, and this could be a result of how the engine is running, especially if the engine ran hot. Let's make sure of the engine situation before we dive into exhaust / engine performance issues. Does your scan tool support live data? It would be helpful to see if the engine temp sensor is doing it's job correctly.

William
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Thursday, June 12th, 2025 AT 1:57 AM
Tiny
BLAKKMAGICK
  • MEMBER
  • 4 POSTS
That's good to hear. My scan is very basic but I can purchase a better one to check and get back to you. Ill also verify if the other fan is operating as well.
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Thursday, June 12th, 2025 AT 4:07 AM

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