I did my first coolant flush today and followed the helms manuel. I drained the coolant, flushed the system with a hose and filled the radiator back up with coolant. Then, I started my car to let it warm up with the radiator cap off, the heater all the way up. I had it running for 10 min and the fans wouldnt come on. What am I doing worng here??

 

I didn't undo the drain bolt on the block becuase I don't have a ratchet big enough to fit it. I didn't think it would be that big of a deal to leave a little coolant in the block.

 

when I was doing the same thing, the fan didn't come on either... I did drain the block too. Maybe you need to run the revs up higher to heat up?? So far I haven't had any trouble with overheating after changing my coolant.

 

you need to turn off the heater after getting all the air out of the cooling system and put the cap back on. this way the radiator fan will come on when the engine is fully warmed up. the heater will act as the radiator fan if you keep it on.


[Modified by vhd, 6:07 PM 7/21/2002]

 

VHD is my hero!!!

 

hahaha....the hero thats not gonna help you put your turbo in for you. just playin

 

was doing a coolant flush and the fans never came on...

bringing back an old page. What does he mean by "turn off the heater" bring the hot dial back to cold????????????

 

yes


that closes the valve that allows coolant to flow into the heater core under the dash
that way the engine has less coolant to heat up b4 activating the thermostat. then you have to wait till the radiator has had enough hot coolant allowed past the tstat to raise its temp and trigger the fan

after a flush it will take forever(seemingly) but that is good, as long as the car gets to running temp and stays there

 

thanks for the fast response
so should i just bring it back to cold after i finishing draining? or let it run for 10 minutes with dial at hot then bring the dial to cold?

just being careful, i dont want to drive and my engine seize because the temps skyrocketed.

 

just open it(to hot side) while you are flushing and draining/refilling

then once you start the engine close the valve(to cold side) after a min or less. you just want to be sure it isnt full of air. you want to keep it closed during all engine adjustments

 

You just have to let it run until it warms up and BOTH radiator hoses get hot. It usually takes my car at least 45+ minutes idling before the fans ever kick on, and nearly that long for both radiator hoses to get hot (thermostat opens).

Also, you really need to drain the engine block when flushing coolant. The block holds at least 1/2 the coolant in the system. Sure it will come out when flushing, but then you'll be left with a bunch of water in the block, and if it's hose water, that is NOT a good idea to leave in the engine. Your 50/50 coolant/distilled water mixture will become more like only 25% coolant and 75% water, and 2/3 of that water is going to be non-distilled with a bunch of minerals that can harm the cooling system. You should ALWAYS drain the block after flushing the cooling system.

The Helms procedure really only covers draining and refilling. This is where something like a Haynes manual comes in handy, as it goes through the actual flushing procedure.

Here is a post I made years ago covering the correct coolant flush procedure:
https://honda-tech.com/forums/showpo...46&postcount=7

 

thanks eddie......
did my coolant drain and flush yesterday.
Drained the radiator and block. patrick, what do you mean there is a bunch of water in the block?

took about 10-15 for my fans to kick in. held the revs at 2000 rpms for a few minutes and they kicked in.
also you said shut off the engine while the coolant lowers in the radiator, i just kept on adding while the engine was running.
temperature where i live was about 50f, so not too hot.