Replaced the thermostat when the engine showed cold. Refilled the system and bled air at the thermostat housing. Tempeture was normal for month or so and started climbing at idle, after driving the car for a few miles. Bled air several times and have added coolant twice. The overflow tank is brown inside and some bubbles are coming into the tank when idling. No leaks show up on the floor or engine. This is a 3.8 engine with 181K miles, has run very well until now. amy help is appricated.

 

try burping the system with the heater on high defrost you may have an air bubble in the system hiding in the heater core. also check your oil for a milky look to it cause you could have an internal intake or head gasket leak. you can get a test kit for the head leak.

 

The oil is clear, not milky and the amount of air is a lot. I cracked the purge valve about a quater of a turn and air came out for about 30-45 seconds. I suppose the test kit is at the auto supply store? Thanks for the ideas.

 

Rented a hand pump and adapter set from Oreilly, found the plastic ell under the belt tensioner was broken. I bought a new tensioner because the water ports in the old one was pitted and might not seal. Two new ells were included in the box, installed the ells and repressured, one ell leaked at the o ring. Tried several times to seal, but would not hold. The passage in the block was rough, so I gave it a coat of blue sealer. I will try pressure again in the morning, hope I can report the job completed.

 

Happy to report the repair is complete and works fine thanks for the help