Temp Gauge Problems. Need help diagnosing.

Some background information on the car. I bought another 6th gen accord couple days ago, but this one is a 1999 LX 4cyl 5 speed. I checked the carfax before I bought it and it stated the timing belt and water pump was replaced at 110,000 miles which was 20k miles ago. The gauge only goes up 10 lines from the big white line on C when warmed up. When I compared it to my 2000 4 cyl auto, there was a difference when fully warmed up. Not significantly, but enough to make a difference to me. The car idles fine, does not shake, and no CELS, does not overheat, mpg is fine so I know the car is not consuming extra fuel when cold.

When I'm on the freeway, the gauge would drop back all the way down to 3 lines above the big white line on C. The only solution I've tried was to bleed the coolant hoping there was just some air bubbles trapped in the system. I've searched a bit and I came up with these threads.


Also is there a way to manually make the fans come on when I'm idling? I want to make sure the fans acutally work because I'm not sure if I heard it come on yet.



http://www.6thgenaccord.com/forums/showthread.php?t=33272&highlight=temp+gauge&page=2


http://www.6thgenaccord.com/forums/showthread.php?t=33929&highlight=temp+gauge+problems

It could be the thermostate being bad

There are two sensors for the temperature indications, one triggers the fans, and one triggers the cluster. In my case the A/C switch will cause both fans to come on. My cluster indication varies with load and as long as it's not swinging wildly I wouldn't be too worried. The sensors aren't terribly expensive or difficult to get to if you want to swap them just to be safe.

Agree with chrismister2k1, sounds like a bad thermostat.

chrismister2k1 said:

It could be the thermostate being bad

Click to expand...

i will replace it after replacing the sensor on the block.

lashlee said:

There are two sensors for the temperature indications, one triggers the fans, and one triggers the cluster. In my case the A/C switch will cause both fans to come on. My cluster indication varies with load and as long as it's not swinging wildly I wouldn't be too worried. The sensors aren't terribly expensive or difficult to get to if you want to swap them just to be safe.

Click to expand...

I just confirmed that both my fans come on when my car is warmed up, and I turn on the AC. Does this mean my fan switch is fully functional?

TheMole said:

Agree with chrismister2k1, sounds like a bad thermostat.

Click to expand...

thx for feedback.

If you want to check that your fans are working properly if the car overheats, run the car at park/neutral with rpms at 1500-2000 for about 10 minutes. That should be enough to raise the temp past 96C and turn on both fans in order to cool the engine. If they do not turn on, you've got an issue with your fan switch I believe.

That being said, usually your operating temp should be anywhere from 88-93C (at least how it is in my 99 accord). If you are worried the gauge isnt displaying the correct temp grab an obd2 bluetooth adapter off ebay and use a laptop or android phone to read the live data.

That being said my temp gauge has a mind of its own at times
http://www.6thgenaccord.com/forums/showthread.php?t=43453
I use a cheap android phone and torque that i leave plugged in at all times just in case my temp gauge wants to nap. You can preset alarms in case certain sensors go over your preset limits on it too.

YounGLeMoN said:

i will replace it after replacing the sensor on the block.



I just confirmed that both my fans come on when my car is warmed up, and I turn on the AC. Does this mean my fan switch is fully functional?



thx for feedback.

Click to expand...

Yes, that indicates the fan switch is still working. That narrows down what you need to replace.

001Stunna said:

If you want to check that your fans are working properly if the car overheats, run the car at park/neutral with rpms at 1500-2000 for about 10 minutes. That should be enough to raise the temp past 96C and turn on both fans in order to cool the engine. If they do not turn on, you've got an issue with your fan switch I believe.

That being said, usually your operating temp should be anywhere from 88-93C (at least how it is in my 99 accord). If you are worried the gauge isnt displaying the correct temp grab an obd2 bluetooth adapter off ebay and use a laptop or android phone to read the live data.

That being said my temp gauge has a mind of its own at times
http://www.6thgenaccord.com/forums/showthread.php?t=43453
I use a cheap android phone and torque that i leave plugged in at all times just in case my temp gauge wants to nap. You can preset alarms in case certain sensors go over your preset limits on it too.

Click to expand...

Just did this test today and both fans came on after 11 mins. thank you.

lashlee said:

Yes, that indicates the fan switch is still working. That narrows down what you need to replace.

Click to expand...

thx for confirmation.


Now it's sensor or thermostat, or gauge itself...

YounGLeMoN said:

Just did this test today and both fans came on after 11 mins. thank you.



thx for confirmation.


Now it's sensor or thermostat, or gauge itself...

Click to expand...

Bluetooth obd2 tool + Android phone/tablet + toruque app(free)=confirming what it is.

If you do not want to try that do this...when the temp gauge needle drops try smacking the gauge/dash with your palm. Don't be gentle as if its glass..give it a good smack and see if the needle jumps back up. If so id say you're experiencing a possesed temp gauge like me.

I'm going to bump this thread that I found by searching rather than start a new one. I hope nobody minds. Since warm weather is here, I figure it may be time to deal with this issue. I have the bouncy temp gauge as well, never going above normal range but usually sitting there like the car is off. By searching, I never found an answer to that.

The other issue is the fan. It always works perfectly as far as keeping the car cool however when you turn on the ac, the 2nd fan does not come on. The confusing part is that if I'm not up to normal operating temps and put the ac on, the same fan comes on that comes on to cool the engine. Are both fans supposed to come on with the ac regardless of temp? I always thought it was 1 for cooling and 1 for ac but I could easily be wrong.

This car is a 98 lx 4 cyl auto if that matters.

Final question is that I am looking to pick up a 2nd 6th gen. It's a 98 ex 5 spd and about 3 seconds after you start the car, the temp gauge goes straight up and never comes back down. Any help is appreciated, thanks