Air trapped in heater core

Hello everyone, I seem to have developed an air pocket in my heater core. I have followed the procedure outlined in the owners manual for burping the system but have had no luck. I also tried using a burping funnel with the nose of the car jacked up with no success.

 

Any tips? I can hear it gurgling in the dash when I shut the engine off!

 

Thanks, Ruby

You may be hearing something else: failing hvac actuator. It also sounds like gurgling when the engine is shut off. But you should only hear it for like 5-15sec after engine shut off.

See: https://legacygt.com/forums/showthread.php/sound-inside-dash-turn-off-car-190728p5.html

 

Does the coolant gauge move when you are at operating temp? Or does it stay at the usual spot when the engine is warm?

Force feed the heater core by removing the heater hoses from the engine and directly filling the heater core. Be careful not to use too much pressure and flush it gently at the same time. Used to have to do this on older Chryslers because of how the hoses were routed.

Fill it to the top and plug the hoses back on and tighten the clamps. Start and run until hot and burp it again.

I need to do that too btw, cause I probably have build up in it resulting in subpar performance on the passenger side vent.

Thanks for the replies and the link! I will do the actuator maintenance, but I am thinking it is a pocket of air. I have noticed the temp gauge drop at times after the car has come to operating temp.

 

I am not sure why the system wont self burp with the over flow at the proper level. I am hoping this is not an underlying head gasket problem. The engine was rebuilt approx 13k miles ago and I do not have any other signs at this time.

 

I will give the force flush a shot this weekend.

 

If I have the hvac system off, then shut the car down, would I still hear the actuator?

 

Thanks, Ruby

Edited August 14, 2019 by RubyLGT

Try bleeding the coolant, if you're able to bleed out all the air I think you should be ok.

 

If you get a never ending stream of bubbles , maybe the machine shop didn't sort out the heads correctly during he rebuild process. Or maybe the person rebuilding he engine didn't even bother taking heads to be machined?

 

Anyway an easy way to rule out he heater core is to simply bypass it!

Have to ask, did you have the heater temp set to high/hot 85F when you started the engine to burp the system ?

I hope the shop did... Ive never taken my cars to a mechanic and have always repaired or rebuilt my own equipment. I bought the leggy already rebuilt by a shop in Portland somewhere a little over a year ago before I bought the car. :x I did get receipes for new oem parts like pistons, oil pump, plugs, gaskets, etc.. No oil or coolant mixing anywhere that I can tell, and the bottom of the engine is clean, so that rules out seepage in my mind. Externally anyways.

 

Yes heater high and at 85

 

No temp fluxuations so far but, still getting the gurgle. I believe I heard the heater door the other day and it did sound different.

 

I dont mean to sound doom and gloom so soon, but I have been eye balling prices on EJ20x engines. Im not sure if I should go that route or just buy a forged and assembled ej255/7 and find some heads to bolt on. I am not looking for max power by any means as the leg is my DD/dad wagon, but a man needs passing power!

 

Im taking the hose to the heater core tonight as JmP outlined

Edited August 17, 2019 by RubyLGT

Confirmed hvac mixer thing!

 

I installed my cubbypod, which is pretty disappointing.... , and noticed that I can hear the gurgle when the white arm is moving.

Great. I just changed one of them about a couple months back. was pretty easy to do. I cannot exactly remember but I think there are four of these actuators: 3 on the passenger side and one on the driver side. The latter requires the dash to be removed which sucks.

If you want these things to last the longest, don't press the HVAC buttons