View Full Version : Radiator Overflow - Bubbling hot???

Lieutenant Johnson
10-25-2010, 11:44 AM
So got a handle on the oil pressure (sending unit) and had got a handle on the overheating issue by replacing Rad , Cap and thermostat!

BUT on the weekend going to Eagle it was awesome except for one time it overheated and Overflow bottle was boiling (bubbling) hot... I let it cool, added some more Coolant and no problem .. http://www.bcjeepclub.ca/Smileys/default/taunt003.gif

My water pump is working , as BobbyB and I checked pressure on the top hose, like I said, NEW thermostat and Pressure cap (16lbs) and NEW Rad with a flush of the engine block. So I have no idea?http://www.bcjeepclub.ca/Smileys/default/huh.gif

maybe a 18lbs Rad Cap http://www.bcjeepclub.ca/Smileys/default/huh.gif

so stumped and pissed off ... help please

dirka dave
10-25-2010, 12:51 PM
Sounds like a vapor lock.

when you filled up the rad did you put your temperature control to the hot position ?

If not it can cause it to over heat.

should be clear up by now.

10-25-2010, 01:04 PM
ya, I would think it's likely an air lock somewhere. Does your cooliong system have a bleeder?
On a different note. Crappy Tire sells "failsafe" thermostats that open when they're shot rather than close like most - a fine option when replacing...

10-25-2010, 01:06 PM
not getting enough fuel? if its running lean it'll run hot, im having that problem with mine

Lieutenant Johnson
10-25-2010, 01:06 PM
NO doubt Balmer ..for next time for sure.

I know it isn't stuck closed though ... thought it may be an air bubble. But how do I check for that??? I have a drain plug on the rad , not sure about a bleeder . thanks Dave

10-25-2010, 01:20 PM
pull the top hose of the thermostat housing till u see fluid puke out of the housing reatach and go not the long tube the upper one

Lieutenant Johnson
10-25-2010, 01:55 PM
So Bryson ... take off the top hose on the thermostat housing??? and wait for fluid to come out of Thermostat housing?

then put back on? what does that do

this is when the engine is off I assume...could you write it more clearly Bryson so I am doing it right ...many thanks!

10-25-2010, 01:57 PM
pull hose fill threw the rad till it come's out = no air in system

Lieutenant Johnson
10-25-2010, 02:20 PM
pull hose fill threw the rad till it come's out = no air in system

Saweeeet !


10-25-2010, 03:24 PM
*CORRECTED INFO.* I believewhat B is talking about is a simply filling the top rad hose with coolant before starting the vehicle. This just makes sure you won't have an air lock happening in the top tube itself. This is the most likely place for an air lock and therefore this is a fine proceedure to start with.
What I was referring to (bleeder valve) is usually found on the thermostat housing or an eaqually high (vertically speaking) spot in the cooling system. If you don't have one (many vehicles don't) then do a simple air bleed this way: Remove the rad cap from the vehicle when cold, start the vehicle with the cap off (place a large pan under the rad to catch overflowing coolant), alow the vehicle to heat up to normal operating temp (the rad will slowly overflow as the coolant heats up) when the thermostat to opens and begins to flow coolant (you'll see the coolant level drop and an obvious flow to the coolant as well) add pre-mixed coolant to keep the rad full, when the thermostat closes again (opposite conditions to when it opened) place the rad cap back on. You are effectively purging the air from the system. This method is a bit risky and should be approached with caution as you are dealing with 160 degree plus coolant.
Also, as the vehicle is heating up it's not a bad idea to squeeze the top hose now and again to force out any air bubbles that may have accumulated in there so theycan escape from the open rad.

Lieutenant Johnson
10-25-2010, 03:32 PM
thank you thank you !~~~

will try today or tomorrow

dirka dave
10-25-2010, 05:04 PM
best way to bleed....

Cut your finger.

10-25-2010, 05:49 PM
Dirka bleeds once a month....

dirka dave
10-25-2010, 05:53 PM
Actually soleil-moon-homo, I bleed every 57 days.

I give blood.


10-25-2010, 05:57 PM
yeah into your tampax [f]

10-25-2010, 09:43 PM
if it keeps overheating and forcing water out you might have a head gasket on its way out
you overheated it up at silver creek bad to split rad like it did
there is a test for combustion gasses in rad

10-26-2010, 10:19 AM
I corrected a couple of my notes in a previous post. Sorry for the bad info... I read too quickly and was a bit drunk...

10-26-2010, 11:35 AM
I had the same problem with my Grand, kept blowing up rads turned out to be head gaskets. I agree with Bruce and you need to get your coolant checked for exhaust gases.

Lieutenant Johnson
10-26-2010, 05:16 PM
Weird... I have not white smoke at ALL or sweet smelling from the exhaust. Oil has ALWAYS and still is looking like OIL not milky. Will have to check rad at home tonight...so almost all symptoms of Head Gasket are not apparent

10-26-2010, 05:52 PM
not gone to that point yet compreshion is pushing past gasket
cheep check to rule it out talk to b at jeep thrills they might have test kit[cheers]have seen many head gaskets gone and didnt smoke white
or water in oil then to you said oil goes milky

10-26-2010, 07:01 PM
Weird... I have not white smoke at ALL or sweet smelling from the exhaust. Oil has ALWAYS and still is looking like OIL not milky. Will have to check rad at home tonight...so almost all symptoms of Head Gasket are not apparent

Same with mine. I put 3 new rads into it thinking I was getting defective rads and turned out to be the head gaskets (V8 Not a 4.0)

Punk in Drublic
10-26-2010, 10:38 PM
i nhad a blowen hg same thing. was lookin for the oil in water or visaversa turned out it was compression pushing into waterjacket=bubbles and overheating. another one, less likely, a buddy had a leaky rad and over did the pepper trick, ended up plugging some lines and pressuring up the rad. took him 3 rads and 2 hoses to find the problem