Help me diagnose my "overheating" Honda Fit before I drive it across four states

My 2007 Fit has had trouble starting for a while – ok, for years – but it’s gotten worse. Here are the symptoms:

  • When I start it, I have to keep my foot on the gas for many minutes until it warms up. After that it runs ok (a bit rough).
  • The dashboard never displays a “cold” indicator anymore, even when it is genuinely freezing and the engine is cold.
  • After a few minutes drive, it starts blinking “H”, and after that it sometimes blinks and sometimes stays steady, but it always claims to be hot.
  • There is no other indication that it is overheating (but I haven’t driven it more than ~10 miles).
  • All the fluids are fine.

My theory: Because it never displays “C” and almost always displays “H”, and because of the starting problem, I believe that one (or both?) of the coolant temp sensors is shot. Therefore, I can… ignore the hot indicator? :grimacing:

My dilemma: I just picked it up today after being away for nearly a year (I was abroad; it has been started occasionally but not driven while I was gone). I really, really need to drive back home about 5-6 hours in the next day or two. If the problem is just a coolant temp sensor, I believe it may run lousy (wrong mix, etc) but shouldn’t be damaged. But if I’m wrong and it overheats, of course, I could wreck it.

I’m considering trying to get the CTS replaced immediately (if possible), but it would be much (much!) easier to get it worked on after I get back.

Am I right that it’s the CTS (or both CTSs?) and I can drive it? Is there another way to track the temp so I can reassure myself it’s not heating? Or should I bring it in immediately and see if I can get the CTS replaced?

thanks for any advice!

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I would get the sensor changed immediately, but if you don’t have time, you could check the radiator temperature with an infra-red temperature gun when the hot indicator comes on. Personally, I wouldn’t drive it until it’s fixed, but I’m a nervous guy

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How long has the “check engine light” been illuminated?

What were the the results of having the onboard diagnostic trouble codes read?

Call me common sense if you’d like, but I wouldn’t drive a broken car anywhere except in the direction of diagnosis and repair.

A bit rough, you say?
You can’t make a good landing from a bad approach. You can thank me, later.
:palm_tree: :sunglasses: :palm_tree:

CSA: good point. The “check engine” light has never been illuminated (yes, the light itself works). The car doesn’t think it’s broken, it just thinks it’s overheating…

Have it checked by a professional.

You’ve been dealing in the dark with this for a long time. Now is the time to shed some light on the problem. Or you can follow your theory and take a gamble like you’ve been doing for years and just drive it.

So, do you feel lucky?

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Another vote for having a shop look at this vehicle . This is not the time to have vehicle trouble on the road . It is bad enough during normal times but with this Virus why take a chance.

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I wonder if coolant is getting into one or more cylinders. This would cause the rough idle at start up. The causes are anything from a bad head gasket to s cracked cylinder head or engine block.

ok, point taken, I will bring it in today. It’s clearly the right thing to do, but it’s logistically complicated because we have to be home four states over by tonight.

Triedaq, I liked my answer about the CTS better than your options of the head gasket or a cracked block :grimacing:

thanks, y’all.

You could have something as simple as a bad thermostat but you won’t know until you have a shop look at it. How many members of your family can drive? One could stay behind while the rest take a rental or bus.

I am paranoid about having car trouble on the highway. I had a 1955 Pontiac that always gave me problems. I was a poor graduate student at the time. I started out on the 350 mile trip home about 5:00 p.m. one evening. One hundred miles into my destination I realized that I wouldn’t make it. I pulled into a mom and pop motel that advertised a vacancy. The proprietor told he had one room left, but it hsd a problem–the television in the room was broken. However, if that didn’t bother me, I could have the room for $4 for the night. I grabbed the room. I haven’t been in a motel since that had a more comfortable bed or thicker towels.
I didn’t know anything about the town, so I limped in to the Pontiac dealer. The service department took my car right away. The mechanic worked on the car for an hour. The bill was $5. I told the service manager that was too cheap. He told me that the repair was only temporary, but the car should get me home. He said he couldn’t charge more because he didn’t want any car to leave his shop that wasn’t right.
I learned two things: 1) not start a road trip in a car that is iffy;. 2) there are good people in the world.

Bad engine temp sensor could keep the mixture from being enriched when the computer thinks the engine is already warm. There may be more than one temp sensor - one for the computer, another for the gauge or light. Good luck and please let us know how this works out for you.