Air In Cooling System
I am somewhat familiar with bleeding the cooling system of air in a 1996 Chrysler Concorde with a 3.5L engine, but here of late, I can't seem to get all of the air removed from the system.
If you have been reading some of my previous posts, I replaced the water pump about 2 months ago, bled the system of air, and all has been well (with the cooling system) since then.
Yesterday, I drove 100 miles to Winston-Salem, and when I parked the car, I lifted the hood to check the overflow tank, and it appeared empty to me. I placed my hand on the radiator cap, and it did not feel hot, so I gently broke the seal, and all of a sudden, coolant began bubbling out.
I immediately tightened the cap, and all seemed well until we began our trip home about 2 hours later, and I noticed the engine temp was elevated somewhat, so I pulled over to check things out. Nothing was leaking, and since the engine temp was not badly elevated, I hit the interstate highway, and the engine temp stayed close to normal at highway speeds.
However, after arriving in our hometown, I noticed the engine temps rising again a bit, but not too bad (about the 10:00 - 10:30 O'clock position), so I assume air must be in trapped in the coolant.
This morning, thinking the air had worked it's way back to the overflow bottle, we started driving around town, and I noticed the temp rising to the 11:00 O'clock position, so I turned around and went home to manually bleed the system of air.
I hooked up some clear tubing to the check valve on the thermostat housing, run the other end of the tube into an empty coolant jug, and cracked the valve to let any air escape (engine running). Some air came out moments later, and then it seemed like the air in the tubing began to bubble like foam. This went on for what seemed like minutes, although I only collected about a quart of coolant in the bottle.
I have never seen air escape this way. Is this normal, or is it a sign of a blown head gasket? Should I try bleeding the system again tomorrow with a cold engine and loose radiator cap?
The engine seems to be running well, and I don’t recall seeing steam from a hot tailpipe just yet.
Last edited by rusty; 11-06-2019 at 12:11 AM.