Need to Bleed Air From 2001 GP Engine Coolant

[terryshrout]

Need a little help with 2001 GP 3.1 L cooling issue. Installed new 190 degree thermostat and changed coolant bypass line. Everything worked well for a few days then temperature Gage became erratic. Needle will spike for a few miles, air from heater is noticably cooler, then Gage needle will drop to an expected reading and heater air will be expectedly warm. Never sure when or how many times this condition will repeat. Seems to be worse after car sits a few days. Have bled air from system several times using bleeder valve near thermostat housing and on coolant bypass line. Have read several opinions as to which valve to bleed with, weather to do when coolant is hot or cold, and how long to leave valve open. I really think the issue is air in the system because the issues are infrequent and unpredictable, just looking for the proper process to get job done once and for all..

[tblake]

Try Jacking up the passenger front corner of the car to get the filler neck higher up than the rest of the motor. Then open both bleeders and add coolant to the radiator.

[terryshrout]

Thanks for tip. Couple of clarification points. Should engine Be running or off? Should coolant temp be cold or hot? Thanks again for the help.

[tblake]

Try it cold first engine off. Then close the bleeders, put the cap on and start it. Then just keep cracking bleeders and checking radiator level untill the car is up to temp. When you are done, fill the overflow resivore halfway up and let the motor cool down.

Some of these 3100's are a pain to bleed. It took me a couple days to burp all the air from a 3400 impala after I replaced the waterpump.

[doctorhrdware]

When I did not know that there was a bleeder screw on the on the tsat housing what I did was to start the car let it run for a minute the pour antifreeze in the radiator cap. I did this until the radiator level stayed at a constant level. When I started working on my GP SE 3.8 L. I wished I knew that this forum existed way back when I started working on my GP.

[terryshrout]

Thanks to all for the tips. Seems that jacking up the passenger side front, opening bleeder valves, then filling radiator did the trick while engine was cold then closing valves and radiator cap, bringing engine up to temp and bleeding air again finished the job. Had bled those valves numerous times with out success. Thanks again for helping finally finish this job. This site and the experts who contribute are indeed a lifesaver.

[tblake]

Thank Rich for the jack up tip, I have also used it on numerous occasions.

Thanks for the update. Good Job.