OVER HEATING WHEN MOVING NOT AT IDLE.

[ROGGEDOG]

Hey guys new here, thanks for being so welcoming,
Down to bussiness just in the last week my Liberty has been over heathing on the move, but as soon as i return it to idle it starts to cool down and will sit happily there until i go to drive off again it heats back up, now i thought it was the thermostat so i replaced that but still the same, I thought maybe head gasket but it has no other symptoms like under power or rough idle, none of the plugs show signs of "wetting" and none of the pistons are polised from buring water dosnt blow and abnormal steam and theres no oil in water or water in oil.
At idle the top hose gets hot but not a whole lot of pressure and the buttom hose comming from the thermostat is cold, and the radiator itself is cold.
The hoses goin to the heater took along time to get hot too, and the heater is hot hardley at all.

I think it might be the water pump but im not sure any one got any ideas.
Help would be greatly appreciated.

[Robbks]

3 problems

1. you need to drill a hole (1/8") in the thermostat diaphragm to allow warm water to pass through it properly and allow it to operate correctly
2. you may have either a blocked heater core and/or airlocks in the system
3. check your radiator cap seals correctly, and holds pressure, if in doubt, replace it

Also do you ever hear the "waterfall" noise from behind the dash?

to flush the heater core, remove the heater pipes from the water connections at the back of the block and flush them with a hose from each direction several times until the water runs clear. you'll be amazed at the junk that comes out.
ALL coolant flows through the heater core in a Gen2
-Ok, now it's flushed, pop off the rad cap and re-fill the engine slowly until it comes out of the heater connections.
-now fill the heater core slowly and keep filling until all the air is out of it.
-re-connect heater-pipes.

Now to bleed air from the system you'll need a coke bottle or brake fluid container jammed in the radiator cap as a "header" tank.
jack the front of the car up as high in the air as possible and get the engine running and warmed up a little
keep the header bottle full
then run the engine at speed (3000rpm) and you should hopefully burp all the air from the system as the car warms up.


failing all of that, it's probably done the head-gaskets, typical for a gen2 2.5L
does it fill the coolant overflow bottle when it's hot?

[ROGGEDOG]

Yeah i sometimes hear that "waterfall" sound what is that, and I put a new rad cap on just recently, and it dosnt normaly over fill the resiviour it cycles normaly as you would expect from use.
And like i said theres really no other signs of the head gaskets blown but yeah ive heard that they have troubles with them.
And the hole in the thermostat thatll just help with warm water circulation. The old one had a small bleeder hole with the "jiggler" in it, and the new one dosnt have anything but it over heather with the old one.

[Robbks]

waterfall noise is airlocks in the heater core
when the airlock gets to the water-pump it doesn't pump anymore.

But i suspect a blocked heater core
flush and re-fill and see what happens

[ROGGEDOG]

Yeah cheers will do ill see how i go, any way to get the air lock away from the pump or thats done by jacking it up and what not.

[foxxy76]

I get the waterfall sound did any of the above advice fix the problem ?

[Adrian2627]

I put a Foz bleed valve in my old BE when I was getting air in the system. Cut the heater line near the firewall on the passengers side, threw in the valve, bled the system and no more waterfalls. Only cost a few bucks and took maybe half and hour to do.