sam31444

Hey all,
Recently my temp gauge has been dropping randomly while driving. I replaced the thermostat last week and seems like it is so still happening. The car tends to heat up almost normal until the heat is turned on and it drops. If the car is started with the heat on it takes forever to reach normal operating temperature.
The thermostat I replaced it with is an aftermarket I got at pep boys but is rated to the same specs.
I also spent an hour with the car running today and the radiator cap off bleeding the system.
Does anyone know what could be the problem?

bsmiley

From the repair manual:
10. Pour genuine Honda All Season Antifreeze/Coolant
Type 2 into the radiator up to the base of the filler
neck.
NOTE:
Always use genuine Honda All Season
Antifreeze/Coolant Type 2. Using a non-Honda
coolant can result in corrosion, causing the
cooling system to malfunction or fail.
Genuine Honda All Season Antifreeze/Coolant
Type 2 is a mixture of 50% antifreeze and 50%
water. Pre-mixing is not required.
Engine Coolant Refill Capacity [including the
reservoir capacity of 0.4 l (0.4 US qt, 0.4 lmp qt)]:
M/T: 4.0 l (4.2 US qt, 3.5 lmp
qt)
A/T, HONDA MULTI
MATIC:
3.9 l (4.1 US qt, 3.4 lmp
qt)

11. Install the radiator cap loosely.
12. Install the battery.
13. Start the engine and let it run until it warms up (the
radiator fan comes on at least twice).
** At this point, I'd turn the temperature selector to full heat, but I wouldn't run the interior fan.**
14. Turn off the engine. Check the level in the radiator
and add genuine Honda All Season
Antifreeze/Coolant Type 2 if needed.
15. Put the radiator cap on tightly, then run the engine
again and check for leaks.



Make sure the front end of the car isn't lower than the rear. You want to have it level or just slightly higher than the rear.
How does the level in the coolant reservoir look?

mikey1

if you live in a cold climate this is somewhat normal,

when you turn the heat on, the blower fan is cooling the coolant the same way your rad fan would,

replacing the thermostat with OEM might help a bit,

sam31444

The level I the reservoir looks fine atm. So install the radiator cap loosely means a half twist?

sam31444

I happen to live in New England but I can tell a serious difference with the cooling system the last week compared to the rest of winter... Considering I did not have this issue operating in -10F weather. I just ordered an. OEM thermo.... Maybe the aftermarket one I installed the other day is sticking open?

sam31444

Update just drove about 30 miles and temperature stayed about half of the normal temp most of the way and heat only got about 75% of its normal temperature. At this point I just ordered an OEM thermo and radiator cap.

bsmiley

Yes, the first stop instead of the second.

mikey1

i still say this is normal if you have the heat blasting the entire time,

my car does the same thing with a fairly new OEM thermostat, temps here are a day time high of about 0 to -5 F

if i turn my heat off it will warm up completely, and alot faster

sam31444

impossible, this is abnormal. On the way to work I threw a CEL. After reading it I got a code for low coolant temp/thermostat. So OEM should do the trick hopefully.