99 honda civic dx hatch temp gauge issue
 

as the title mention my civic temp gauge drop to cold once i rev over 3500 rpm both at idle and driving. can anyone point out where should i start checking first or have this issue before and know what wrong with it? i believe i have the d16y7 engine. any input would be helpful. thanks in advance

Re: 99 honda civic dx hatch temp gauge issue
 

Do you have a thermostat? Are your fans constantly on? Are you sure your temp gauge works correctly?

Re: 99 honda civic dx hatch temp gauge issue
 

wouldnt the car run cold all the time if no thermostat? but fan isnt constantly on and yes the temp gauge is working fine since it overheated on me last week but that problem was fix(heater hoes). just today when i went out and was driving i notice over 3500 rpm the temp gauge would drop down to cold but anything below 3500 it would go back to normal temp.

Re: 99 honda civic dx hatch temp gauge issue
 

Start here:

Bleeding the cooling system may take 20-30 minutes.

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push/turn the dash heater lever/knob to MAX heat. Fan need not be on.

3) Follow the directions in the diagram below


http://i639.photobucket.com/albums/u...cture_3542.jpg

Re: 99 honda civic dx hatch temp gauge issue
 

Bleed the rad like RonJ shows. If that doesn't help, replace the Tstat.

IMO, you either have an air bubble in the system, or a thermostat which is sticking open.

Re: 99 honda civic dx hatch temp gauge issue
 

conclusion after changing my oil and bleeding it twice. the same issue happen but instead of the temp starting to drop at 3500rpm it start at 4000-4500rpm. now as i was bleeding it i didnt pay to much attention to the fan kicking on or not but i was sure it didnt. as ron mention it didnt have to be on so is it the thermostats or im not bleeding it properly?

step i took(the car was on a inclined driveway)
1. the car was slighty warm already from going out but it sat for a good 2-3 hr before i start the bleeding
2.check coolant level in radiator and fill it up.
3.leave radiator cap loose.
4. start the car and turn on the heat up at max
5. let car sit for 20min
6. turn off car, check fliud(fluid was at the top level of the radiator still), check leak, then start revin
i did the same step twice but the second time i waited 30 min. after a test drive the temp startin to drop at 4000-4500 rpm

Re: 99 honda civic dx hatch temp gauge issue
 

Just go and replace the $15 Tstat with another from Honda. Not worth hassling with everything for such a low cost replacement IMO.

Re: 99 honda civic dx hatch temp gauge issue
 

Okay so today i replace the thermostats and bleed it again but im still having the same issue. During the whole time the fan hasnt kick on once. Where would i go next? Could it be fan issue or electric issue such as faulty temp sensor(gauge). Is it safe to drive? It my dd so i dont want to risk it if it not. Only cel that is on is for my o2 sensor because the car came with header

Re: 99 honda civic dx hatch temp gauge issue
 

Bump for some more advice