JDM Civic Hatch

Aight here it is its a b16 into a 94 civic hatch. when he starts the car if it is cold the motor surges or revs till like 3 grand and back down and then keeps doing that till it warms up. then today on his way to work his heat was not working the blower worked but no heat just cold air. He went home and let it warm up more thinking it was just too cold out. (it was about 15 Degrees) After another 10 minutes the heat still didnt work and his car started to over heat like mad. The upper rad hose was hot but the lower one was still ice cold. He checked and the lower was not frozen. Any possible ideas of what could be wrong. Thanks

95IntegraGSRAZ

Somtimes when it revs like that, it means its running low on coolent, I know Ive had that prob. in 2 of then Hondas I have owend, I toped them off and no more reving. O yeah, and they only did it till they warned up like you said, b/c its running in a closed loop system untill the thermostat opens. That might be it?

JDM Civic Hatch

he topped off the coolent a few days ago when it was reving and it didnt stop it then. Could it be too cold for his coolent could he need to flush and refill wit straight coolent? I think he might have cut it wit some water. Thanks

95IntegraGSRAZ

Dont fill with straight coolent, mix 50/50 or 40/60 coolent/water. If its not that then I cant help you, Im still learing about the engines, mines not running now....

ScottEK

With all this coolant talk, what is the proper procedure to fill it. The first time I did it I opened the release valve, the second time I did it I took the release valve too far and made a big mess, the third time I just filled it, started it and poured more in while it was running until it leveled.

VTECVillain

He might have air (vapor lock) in the coolant lines going to the heater core. Try bleeding air from the coolant and see if that helps with the heating problem. For the idle surge try to adjust the Throttle position sensor. They have slight movement for adjustment similar to a distributor.

Lord Helmet

[quote]He might have air (vapor lock) in the coolant lines going to the heater core. Try bleeding air from the coolant and see if that helps with the heating problem. For the idle surge try to adjust the Throttle position sensor. They have slight movement for adjustment similar to a distributor.[/quot3.


Yeah, I had the same problem and that was the culprit.


[Modified by sleeperciv, 8:59 PM 1/22/2003]

976

As mentioned, coolent!
Remember to bleed and only use type 2 honda coolent...

Even if it is full, even to max in resivior you still might have a lot of air bubbles, I think bleed properly (see manuel) will pretain to your friend.

Fast idle valve - try after is coolent top off doesn't work!


[Modified by w00t!, 5:03 AM 1/23/2003]

JDM Civic Hatch

Ok we replaced the thermostat and refilled the coolent and blead the air outta the lines. the surging stopped the heat works and the car stopped overheating. the only problem is that the lower rad hose is still cold while the upper remains hot. Is this normal? i thought that the lower hose should be warm as well once the coolent starts circulating. Well hope some one can clear up our confusion. Thanks

97hb

Sounds like the t-stat. Once the t-stat opens, the lower rad hose should be hot. If not the fault is in the t-stat. Also the reason for not having heat in the car. If it can't get past the t-stat there would be no heat.

Kidnkorner

the correct procedure to fill coolent in a honda is to have the car running, with the radiator cap off. it helps to have a radiator fill container from snap-on tools. let the car idle till its get hot enough to where the radiator fans come on, and the t-stat opens. at this time you begin topping of coolant. u do this until no more coolant will go in. put the cap on, and fill the resevoir up to the correct line, and ur set.

97hb

That is the correct way for Hondas without the bleed bolt.

Phaze2 Mike

I thought that the correct procedure was to open the 12mm purge nut on the therm housing, and fill until only coolant came out of the purge hole, thus meaning all air was purged from the system.

JDM Civic Hatch

We just replaced the t-stat and now the heat works. So the only issue is that the lower rad hose is still not warm it just stays cold. Any ideas? thanks