gabriel0830

i own a 94 civic sedan automatic im running a stock D16z6 vtec engine. i recently replaced the radiator about a month ago because it was overheating. the overheating stopped for a while but than it started overheating once again. it cools down when i drive but heats up when im stopped. also i smell antifreeze when im driving and when its parked. I checked my car there are no leaks what so ever. i check my antifreeze level in the radiator and resvoir tank everyday and there good, so im stuck with this question? why is the smell there and why is it overheating? can it be my water pump? thermostat? any suggestions???
thanks techs

dafreeeze

Change thermostat its easy and cheap bleed the system.

cbaber

Since it only overheats during stops you should check that your fan is engaging. The system relies on the fan to move air when you are in stop and go traffic. On the highway the air from moving usually gets the job done.

X E Ryder

Does your car cool off, like to below warmed up level when you go down a big hill? Tstat could be stuck open - fan was a good call by cbaber also.

Tstat is very cheap, and make sure you turn on the heater and open that little bleeder bolt on the return hose fitting during filling to get the air out, and let it idle until hot water is in the return hose you can feel. Check the bottle after it cools.

That smell - hopefully you don't have a small leak in your heater core - if you get a greasy film on the windows that points to the heater core.

gabriel0830

i jus checkd fan turns on but only after im driving not on start up it turns on like before it starts heating

cbaber

I would recommend flushing the coolant out again. Follow this procedure:

Drain all coolant.
Add your choice of coolant to radiator until it is full.
With the radiator cap off, start the car and turn on full heat with full fan.
As the car warms up, add coolant to radiator as the level goes down.
When no more air bubbles come out, or when it fully warms up, put cap back on.
Fill reservoir to hot level.

Also, when you are in stop and go and your car starts to overheat, turn on the heat full blast. Does the coolant temp. suddenly drop?

This is sounding more and more like a headgasket issue. You shouldn't smell coolant. I bet if you checked a week later you would have lost some coolant.

gabriel0830

so i turn on the heater???

gabriel0830

i jus drove my car to a friends house and all the coolant in the resvoir tank was hot like boiling hot

cbaber

Yes because something is wrong and the radiator is not able to cool the coolant.

Do as I said and flush the coolant properly. Yes, turn the heater on full blast, full heat while you do this with the radiator cap off. You should see bubbles and then when the bubbles stop the system is free of air. Replace the cap. Turn heater off.

Then once you are sure no air bubbles are in the system start the car again. This time, watch the temperature. You can rev it up to 2-3k RPM for awhile to warm it up quicker. As it approaches the normal operating temperature the fan on the radiator should kick on. Does it kick on before it starts to overheat?

gabriel0830

yaa it turns on like a couple of minutes before it heats up but

cbaber

But....

Are you sure it never overheats when you are driving at a steady speed, like on the highway? If so, could also be the water pump. For good measure before you start major repairs, swap out the thermostat. Cheap and easy insurance. From there if you radiator is good, fan is good, no air bubbles, and no leaks in the system I would start with doing the water pump and timing belt.

jbpnoman

The heat doesn't have to be blowing, it just has to be on to properly bleed the car.

gabriel0830

yaa like todayy.. im driving in the city hitting the highest about 55 mph when stopped at a light car starts to overheat so when i start driving it stays heated but slowly goes down around 45-50 mph it lowers to normal temp or close to it.. radiator is brand new, ima change that thermostat tomorrow and hopefully it fixes the problem

jbpnoman

Sounds like classic fan not working symptoms.

You said you replaced the radiator. What did you replace it with? Did you replace the fan, or modify/remove the shroud in any way?

gabriel0830

i replaced it with a brand new radiator thas all same fan

cbaber

If the thermostat was not opening it would get hot all the time, driving or not. The fact that your engine needs to be at speed and your fan is good tells me that its the water pump.