What could be wrong with my 2004 Chevy Monte Carlo when I keep having to bleed it out and it keeps getting air in it?


Asked by Dec 04, 2013 at 10:09 PM about the 2004 Chevrolet Monte Carlo LS

Question type: Maintenance & Repair

Any help would be appreciated.  I have no heat some of the time and then I have someone bleed it out and it works for a couple days then it happens again.  I have had the water pump and thermostat changed.  Now my check engine light comes on and O'Reilly's says it's a p0301 code which is a cylinder 1 misfire.  I just don't know what to do next?  I only have 75,000 miles on it.  The oil looks fine, no leaks that I see, antifreeze in the reservoir doesn't go down.  The one hose to the heater core is cold and it just seems like its plugged.  Any advise what to do next or what it could be?

10 Answers

what do you mean "bleed"...the coolant pressure gets to be in excess of 17 PSI?~

as far as the misfire...would replace defective wires, coil packs on the number one~ https://www.google.com/#q=2004+Chevy+Monte+Carlo+coil+packs&tbm=sh op


Chances are that you need to have the system bled again (if your model requires it to be bled). I have an 04 Alero and after I changed the water pump I had to bleed it twice (once when cool and once when it is up to normal operating temperature with the heater running on full).


judge_roy - It has over heated where I had to pull over and wait for it to cool. Since then I have had the thermostat changed and water pump. I am not sure of the in excess of 17 PSI? LOL I don't know much about cars.


Michael - I have heard that before. I will try bleeding it again, maybe I will take it to a garage to have done this time. Thank you


One other thing...my owners manual says when bleeding the car take off the radiator cap. O'Reilly's says never take off the radiator cap that's what the bleeders are for. The mechanic that changed the water pump also said it may need bled a few times and to take off the radiator cap and fill with antifreeze. Which way would be best do you think?


Bleed the system with the radiator cap off. You'll want to pressure test the cooling system as well as the radiator cap itself. System should hold 16 PSI for at least 10 minutes. If you don't see anything leaking start the engine with the system under pressure. If the needle on the pressure tester's gauge starts bouncing you've got a blown head gasket. Take a vacuum reading as well. Intake manifold vacuum, at idle, at sea level, should be about 21 inches. If it's considerably lower suspect a leaking intake manifold. HTH. -Jim


Yes, to bleed the system when cool.. Remove the cap and open the bleeder screw. When coolant flows out the screw close it. Some vehicles have two bleeder screws (not sure on your model). To bleed when running (DO NOT OPEN THE CAP). Just open the bleeder screw slightly until it starts leaking. Leave open until it stops burbling.

1 of 1 people found this helpful.

Yes I have 2 bleeder screws on my vehicle. Ok, I will try this again. I appreciate all of your help. Thanks so much everyone!

1 of 1 people found this helpful.

You're welcome. Glad to help. -Jim

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