Legacy cooling problem
 

I know this is an SVX forum not a Legacy forum, but I reckon somebody here will know the answer to my problem.

My '96 2.2 Legacy has an overheating problem. The water in the engine is boiling but the water in the radiator remains cold.

My first thought was the thermostat might be stuck closed, so I cut the centre out of it with a hacksaw. Then water started pouring out of the weep hole on the water pump - meaning that the ceramic seal had failed. So I've just fitted a new water pump and thermostat - but the overheating problem remains.

Once the engine warms up, the top corner of the radiator (near the inlet pipe) is hot but the rest of it is cold. I wondered if the radiator might be clogged, but if I squeeze either hose, I can make water overflow from the filler cap - so there's definitely a pathway through it.

I reckon the heat is spreading to the radiator via convection rather than the water being circulated by the pump (ie. stat closed or other blockage). I keep thinking that maybe there's no water in the water pump, hence why the stat isn't opening and why the seal failed.

My plan is to try the gutted thermostat again as this will at least ensure that I don't burn out the seal in the new pump. And while I have it apart, I'll pour some water into the top hose and see if it find's it's way though the block down to the pump.

I don't understand how the engine is supposed to fill up with water. Obviously it has to fill through the bottom hose, but if the stat is closed then it can't - and if there's no water in the engine then the stat won't open. Catch 22 AFAICT.

Anybody got any ideas?

stupid question, are you using 50/50 coolant and water, or just water.. or just coolant..

I normally use Antifreeze and Water in whatever proportions are given on the antifreeze bottle. While fixing it I'm just using water to test with. No point in using expensive antifreeze just to have it leak out or boil away.

I don't think the mixture would have any bearing on my current situation, but I presume you are leading to something?

First, reverse flush your cooling system with water. Then refill it with antifreeze and water (usally 50/50 %).
Second, pull the water pump and see if you have an impeller left.
Third, check your oil to see if any water/antifreeze is leaking into engine oil system. If oil is has whitish/grey color, you have a leak. Then check head gaskets.

Now I have a question for you. Why didn't you just remove the themostat. Put it in a pot of water with a thermometer and heat it up on the stove to see when it when it opens (usually at ~180 deg. F), rather than hack it up with a saw.

Larry III

'97 Legacy Outback w/2.5L engine & 4-EAT tranny

From what you say this could be a head gasket leak.

QUOTE=svx_commuter: "From what you say this could be a head gasket leak"

My thoughts exactly, this isnt a stupid question at all, rather a most frustrating pronlem that i myself have lived through with an earlier model liberty.

I flushed the radiator, had it flushed profesionally, repalaced all coolant hoses, went through 3 thermostats, 1 water pump, 20L of coolent, and a **** load of stress!

Do what these fellas sugest first, but worst case senario is a head gasket gone!

On liberties if the gasket blows on the exaust side it can be very hard to tell, mine didnt even show up on pressure tests! Are you loosing coolant??

the problem got worse and worse untill more visible signs appeared such as oil in the coolant (six - eight months after first overheating incident)

I got around by drilling 3 holes in the thermostat so the car always ran cool! (no heater sucked in the winter)

If you want more answers and how tos try this forum and search around a bit, loads of info here ;)
http://www.rslibertyclub.org

cheers,
Jake