woodly1069

hey guys I was wondering if anyone knows how this is supposed to work. I have a 2000 Civic 1.6L with the single overhead cam. This thing has an overflow tank for the radiator and a cap where I can fill the radiator. Why would the level in the radiator be low but the level in the plastic reservior be ok? I can't seem to understand why the radiator will always be low and then when I add to it it goes into the plastic tank and makes it overflow??? Any thoughts would be great!
Thanks!

ezone

Everything between the radiator and the liquid in the bottom of reservoir must be sealed (meaning the tubing), otherwise it would be like drinking from a straw that has a hole in it.

The tube must actually reach the liquid in the reservoir too. The liquid can't defy gravity and jump.




The radiator must be completely full and system burped of air. If there is a large air pocket in the cooling system, there won't be sufficient vacuum to pull liquid out of the reservoir as the system cools.

The seals on the radiator cap must be perfect, as well as the sealed surfaces in the neck of the radiator.


Head gasket must not leak combustion into the cooling system. A blown head gasket will often push liquid out of the radiator, leaving a huge air pocket in the system...then it can't pull liquid out of the reservoir.

woodly1069

OK, how would I be able to see if the head gasket is blown and leaking into the coolant? Bubbles in the radiator when it's running or something?

ezone

Proper testing, duh!

Yes, that's one way.

Does it push the liquid out of the radiator and overfill the reservoir?

Do a search for head gasket or something on here, I've replied to a ton of posts about 7th gens-- but the method I use to find a combustion leakage problem is the same.



Check out how scooty figured out his, see the video:
https://www.civicforums.com/forums/182-7th-gen/352984-idle-behavior-normal-vid-included-redid-thtle-body-clean-worse-now-2.html#post4629441

woodly1069

The radiator is never wet on top, I think it's sealed up good. The overflow always comes out of the reservoir.

Thanks for the thoughts!

ezone

Does that mean it pukes coolant out from the reservoir?



If you only filled the reservoir to the "max" line (or however yours is marked), this shouldn't happen. That leaves plenty of room for normal fluid expansion as the temperature changes.

If you fill the reservoir completely full it will definitely puke.

woodly1069

Nope I have never added anything to the reservoir. At one time it was to the full mark with plenty of room for expansion but seems to be filling up as I add to the radiator. I think it must be a blown head gasket as it seems the combustion is pushing the coolant back into the reservior from the radiator...DAMN!

woodly1069

Yep, just checked and it's blowing bubbles into the coolant reservior. That's why it's "adding" coolant there and pulling from the radiator. It blows bubbles at idle slowly and when I rev it up it blows them faster into the coolant...DAMN!