2000 taurus wagon bubbles in the coolant bottle.

Just as a qualifier, I am an earthmoving machinery mechanic at a dealership ie: diesel's and computers. (no gas engines)

Inlaw stopped and asked why the temp gauge just ran to Hot. I looked at the coolant bottle (engine off) and it was empty and steamy. After the engine cooled a bit I added some coolant and the temp was okay. I installed a NAPA coolant block test kit and when the engine was started the test bottle was blowing bubbles and alot of them. The chemical turned instant yellow. I thought the head gasket was blown. While the engine was hot I checked each cylinder compression and they all ranged from 65 to 70 psi ( very uniform). ??? Started from scratch and vacumm filled the coolant system. Still alot of bubbles and the chemical turned yellow indicating exhaust gas. After a while I noticed a water line from the top of the t-stat housing going to the intake manifold. Maybe it is a water cooled intake?? I pinched off the small hose and the bubbles stopped. My guess is the intake is cracked internaly? Is there enough pressure in the intake to ingress the coolant line? Or is this bubbling coolant normal on these engines?

NOTE: very poor coolant maintenance, the bottle is loaded with rust and you can here the corrosion crumblies when you squeeze a line.

Any idea's.
Thank you, Gary

Oop's forgot the engine info. It has a 3.0L V6

Nope, the bubbles are not normal, and the compression seems somewhat low. Did you by chance pull the engine oil dipstick and check it for signs of coolant contamination (chocolate milk-like appearance)? Sounds like a good liklihood the car has a bad head gasket or cracked head.

Did you happen to notice if the cooling fan was running while the engine temperature was high?

-Rod

The engine oil is clean. I did not see the fan turn on. The top rad hose was hanging around 180deg F after i filled the coolant. I wasn't trying to get it hot. When I get home I will see if the fans work.
Good info, thank you.

You should also be able to turn the A/C or defrost on to activate the cooling fans. If the fans don't turn on with the A/C, then there is a chance the cooling fan motor is shot. Obviously this won't fix the bubbles, but would need to be remedied prior to replacing the engine or determining the bubbles are caused by something else. Ie: you don't want the engine to overheat in the future.

Do you notice any signs of coolant in the exhaust (sweet smell or white color)? Have you tried pressurizing the cooling system to see if it holds pressure? Also, check the passenger side floor for moisture in the carpet, signs of a leaky heater core. If the cooling system has been neglected, there could be high liklihood the heater core is corroded and leaking (as well as a liklihood pressure testing the cooling system may cause it to leak if it isn't already).

-Rod

Well that was easy, I showed up to work and the inlaw had it towed to a Ford garage. Double points for that one eh'. I will update the post when the problem is found. She forgot about an extended warranty she purchased and they said it should be covered.

Good news for the both of you! :) Please do report back with the results.

-Rod