I have a 99 civic ex coupe with the stock d16y8 and i have no heat. I changed the thermostat twice, flushed the heater core, flushed the coolant system, and i still have no heat. The upper radiator hose is hot, but the one coming from the thermostat to the radiator is ice cold, even when i drive over 20 miles. Its starting to get cold and im trying to fix my heat. is there anything else i can try? A local shop wants to charge me $500 to take apart my dash to make sure the vents are opening correctly.

 

Air in system?

 

is your water pump working. is the engine overheating? i have found obstructions in the heater control valve before.

 

thermostat is not opening

 

What brand Tstat are you installing? IMO, I would just with one from Honda.

 

The cars temp stays below half, it never overheats. I used a Gates thermostat, and now im using a stant.I tested both before i put in in boiling water and both opened. I installed a new timing belt/water pump a few months ago. how would i know if my water control valve is messed up? I had a friend who put the valve to full heat, and its still not hot

 

an obstructed or broken water valve can stop you from having heat in the vehicle however it has no effect on the lower rad hose. if the lower rad hose stays cold even at op. temp. then you have another issue (air in system or tstat not opening) also, are your rad fans turning on?

id have to guess air in the system, personally because the tstat not opening would not affect flow to the heater core (both in in and the out lines to to and from the heater core are before the tstat housing) and the water valve broken or sticking would not prevent flow to or from the rad. does your engine have a bleeding port near the upper rad hose? also bleeding the coolant with the front jacked up helps.

let me know if you want more or clearer info

 

Pm'd you. My d16y8 doesn't have a bleed valve on the radiator but I searched and saw that you have to jack up the front of the car and top off the radiator reservoir with the Car on. Does anyone have experience with this?

 

Do exactly what you just said. There is ALSO an EXTENSIVE FAQ at the top of the forum that should have a link or two that outlines it. It may even have pictures.

 

i have a 2000 Honda civic LX and the upper radiator hose gets hot but lower hose stays cold after driving car around for awhile. i'm trying to find out the proper way to bleed the cooling system. there is no bleeder valve on engine also.

 

Did you check the faq up top?

 

3 year old thread being put back to bed. /thread