99 Kia Sportage Overflow tank Foaming

[cwhebel]

I have a 99 kia sportage and i've posted a thread a while back about my heater core issues.. this is something new though and I don't think related... I have now replaced my radiator because after we bypassed the heater core it was overheating alot and my radiator was bad so we thought that was the issue... on it's last day of the old radiator when i was driving it to my parents to get fixed... the huge radiator hose blew off and the gage never read hot and it was ran for maybe 5 min to get there... now after the new radiator the car runs cold... it never gets above the 1/4 mark on the temp gage... now the other day i ran it for 25 min to work and when i got to work i saw that the wheelwell had antifreeze on it and it was dripping down off of there... opened the hood and it wasn't smoking and didn't feel hot.. but i did open the overflow tank and it was foamy... my oil is clean not milky.. and the car idles and runs fine... just running cold and so far just the one time yesterday was foamy... i had the radiator cap tested today and was bad so i'm replacing that... i know that their is air going through the system from somewhere just want some advise... now i can't do a compression test unless i want to replace my gaskets cuz if where they are located(which is stupid i think) but i heard of a cylinder test??? is that possible or probable to test the head? and how do i do one without needing to replace anything just to do the test?

[Tazzy666]

Hi cwhebel,

Well this sounds like to me that you may have a bad thermostat(located between top radiator hose and motor block).

The thermostat is not operating properly(not opening when reaching temp) causing pressure build-up in the antifreeze lines(hoses).

Now since you by-passed the heater core will even cause more pressure because the heater core allows the antifreeze to flow more freely through the system, this will make the car overheat easier.

I would recomend a leak-down test through the radiator(radiator pressure test) and check for antifreeze and air leakage(spray bottle with soapy water around head gasket area).

It is possible that you may have a head gasket leak(doesnt always leak into the oil part) but you did not say if radiator was going low on antifreeze after running awhile(could be leaking out the exhaust(white smoke out exhaust) or even leaking out on the side of motor).

Tazzy666