2000 Legacy Wagon Coolant Problem

[Pete2000]

When the engine is cool is the coolant supposed to be up to the level of
the radiator cap? My radiator seems to transfer about a cup of coolant
into the overflow every time I drive the car but it is never gets sucked
back into the radiator when cool.

When the engine is cool again, I remove the radiator cap and fill the
radiator up to the top. I even make sure I squeeze the top hose to get
the bubbles out. I know it sounds like there is is a bubble in the
system, but I have done this at least 10 times.

 

[Carl 1 Lucky Texan]

Hope for a bad radiator cap.
next, try parking on a severe inclune or run front wheels up on
ramps.Put climate control in highest heat setting. Start and run till
hot, check coolant level, allow to cool, repeat and confirm coolant level.
if the above do not help the condition, check for exhaust gasses in
coolant system(bad headgasket)

Carl
1 Lucky Texan

 

[Pete2000]

I think I have done all that (incl. new cap). What do gases in the coolant
system look like? I know that after I turn off my car, I look into the
overflow container and I see air bubbles coming from the radiator bubbling
inside the overflow.

Would the car drive any different if the head gasket had a leak? Car
drives great. Would coolant leak out of the head gasket onto the hot
block, or does air just leak in?

 

[Gilles Gour]

When the engine is cool is the coolant supposed to be up to the level of
the radiator cap? My radiator seems to transfer about a cup of coolant
into the overflow every time I drive the car but it is never gets sucked
back into the radiator when cool.

When the engine is cool again, I remove the radiator cap and fill the
radiator up to the top. I even make sure I squeeze the top hose to get
the bubbles out. I know it sounds like there is is a bubble in the
system, but I have done this at least 10 times.

At best and most probable you have a bad rad cap. Replace that first,
it's cheap.
Also check the small diam hose that go from the rad to the overflow
reservoir. It might be craked somewhere.
At worst you have a leaking head gasket.

 

[Carl 1 Lucky Texan]

A small leak from combustuion chamber to coolant jacket may not affect
the engine enough to notice. Sometimes comparing spark plugs will help
identify which cylinder is involved(it's the cleanest one).
I have heard of, but not used, a test strip of some type that can detect
combustion by-products in the coolant. Sometimes observing in the
radiator itself, not the o'flow bottle, will show gas bubbles while
idling. A 'sniffer' such as is used for emissions testing can sometimes
detect exhaust gasses from a radiator.

good luck!

Carl
1 Lucky Texan

 

[Gilles Gour]

A small leak from combustuion chamber to coolant jacket may not affect
the engine enough to notice. Sometimes comparing spark plugs will help
identify which cylinder is involved(it's the cleanest one).
I have heard of, but not used, a test strip of some type that can detect
combustion by-products in the coolant. Sometimes observing in the
radiator itself, not the o'flow bottle, will show gas bubbles while
idling. A 'sniffer' such as is used for emissions testing can sometimes
detect exhaust gasses from a radiator.

good luck!

Carl
1 Lucky Texan

I'm afraid those bubbles in the overflow reservoir are a symptom of a
head gasket failure. Combustion gases get into the coolant. This is
phase one. Later the leak will be enough for the exhaust gas to push the
coolant out of the rad thru the overflow reservoir. Dont delay in
having this diagnosed for sure cause overheating could desroy heads and
even block.
Good luck!

 

[Edward Hayes]

Did you replace the radiator cap with a OEM cap for YOUR model? I have read
of problems with after market caps as well as the dealer selling the
incorrect cap. ed

 

[Pete2000]

Based on everyone's input, I suspected a head gasket leak. Took it to the
dealer this AM. Suspicions were correct. Dealer is repairing under
RECALL warranty.