estridge48

I have a 2007 Civic and it takes a long time to heat up. I can start it in the morning and let it run for 15 minutes and the temp gauge doesn't even move. The air from the heater is barely warm and I have to drive the car to actually get it up to operating temp. What's up?

Mad Dog Tannen

Could be a bed thermostat or fan switch. Most likely the thermostat.

Mad Dog Tannen

^ I take it back. I am almost positive it is your thermostat.

gearbox

iTrader: (95)

yeah more than likely the thermostat is stuck open.

Kennykid2002

iTrader: (1)

Hmm, I know older cars usually have to warm up before driving, especially in cold weather, but
how much difference does it actually make to warm up your car?
Any bad effects of not warming up your car?

Usually what i do, i dont even watch temp gauge, i just let it settle to under 1k RPM and start driving, or sometimes i dont even let it warm up.

gearbox

iTrader: (95)

yeah there is. the longer it takes the car to reach operating temp, the more gas is wasted and the ecu continues to run in open loop by dumping fuel in and this can cause all sorts of problems esp in the winter. sensors and cat may be destroyed, engine may start getting deposits, etc. you need to warm up the car fully each time you drive. if not, you wont like what the engine looks like later.

Kennykid2002

iTrader: (1)

Hmm, I guess i'll try to as much as possible, but sometimes when u gotta go, you gotta go :P

And plus my car is garaged, so it doesnt get cold. My garage is a constant 70+ degrees, even in the wintertime.

gearbox

iTrader: (95)

the winter issue was referring to driving, not storage. driving in winter takes 2x longer to warm up the engine and its much easier to cause damage. they say you should drive at least 10 mins in summer and 20 mins in winter to get the engine up to temp. ofcourse this varies depending how cold it is. it sometimes took 30 mins just for my temp gauge to move up past the cold mark when it was -15F outside. the seats were so hard it felt like i was sitting on wood lol

Kennykid2002

iTrader: (1)

The bay area doesnt get cold enough to freeze

Average temp ranges 50~80

Extreme temps here go from 40~110

Today was mid 70's and I watched my temp gauge go up about 2/5 (operating temperature) at idle in about 2 mins

Mad Dog Tannen

You only really need to warm it up in freezing cold weather. Modern engines warm up pretty quickly and are alot stronger than older cars. I would just baby it until it reaches normal operating temp.

estridge48

I don't think it's the theromostat because the car does get hot air and the gauge reaches operating temp after driving for awhile. A few co-workers with Hondas have the same situation. If the stat failed it would default to the full open position and I wouldn't get any heat no matter how far I drive.

Mad Dog Tannen

It will warm up more quickly if you are driving it. At idle it's burning a fraction of the fuel compared to driving, which is what causes almost all of the heat to begin with.

How long does it take to warm up?

gearbox

iTrader: (95)

this is exactly due to a thermostat stuck open. instead of being closed to limit the coolant that circulates in the engine (so it warms up faster), you instead start with the entire coolant supply running thru the engine like what happens once the engine is warmed up. so you will be warming up alot slower like 15 mins instead of 5 mins. eventually it will warm up, and you prolly wont hurt anything immediately, but it should be fixed. its much worse to have the thermostat stuck closed, because then you will only be using a small amount of coolant (no radiator cooling) and this can cause overheating.

you do realize that once the car is warmed up and driving normally, the thermostat stays open pretty much 99% of the time? its supposed to be open during normal driving once the engine warms up. it only stays closed until the engine warms up. then thermostat opens to allow cooling thru the radiator. the only time you will not get heat is when the thermostat is closed and blocking coolant from reaching the heater core under the dash. if stuck open, coolant immediately starts flowing everywhere, which is why it takes so much longer to warm the car up.

Jay Riche

Insure that radiator and heater core are completely filled with antifreeze mix.
Also check temperature of radiator hoses with your hand, while the car is still relatively cold. After 10 minutes both hoses should at least be fairly warm ( if the car is sitting still). Then, change the thermostat if you still have little or no heat. It is inexpensive to do this and might even be the quickest way to troubleshoot the heating system. If the cooling system is filled with rusty coolant, your heater core might be plugged, which would not allow the heat to be transferred to the inside of the car. You would need to flush the system if the core is plugged.