06-09-2008, 10:53 PM
I know I've gone on ad nauseum about my car's overheating problem on a nearby thread, but, since I *think* (thanks to a lot of very good inputs) the culprit may simply be that I've managed to trap some air into the system that I haven't been successful in getting out, I wanted to start a fresh thread just on the topic of bleeding the system, which will hopefully turn into a DIY.
As a quick recap, my problem is a lack of coolant flow back to the radiator, and I've ruled out the thermostat, water pump, clogged radiator, and collapsed hoses. The leaves air trapped in the passages, and passages clogged with some other foreign matter. Since attacking the former is free, I wanted to run something by everybody.
I'm skeptical that the standard method of pressurizing the system, and cracking the bleed screw open, will remove air pockets trapped in the bowels of the cooling system, at least without making a huge mess all over my engine and garage floor; I think I need stronger medicine. So here's what I'm thinking:
1. Open the heater
2. Replace the bleeder screw with a fitting, and attaching a clear tube to the end of the fitting. Run the end of the tube into a bucket.
3. Open the radiator cap, insert a funnel, and have a gallon of antifreeze (yes, glycol-free) and DI water mix on the ready.
4. Turn on the engine, and watch the coolant as it drains out the fitting and through the hose
5. As the coolant level in the reservoir drops, fill it with the fresh coolant. Never let the reservoir run dry!
Continue until there isn't a trace of an air bubble coming through the hose. Allow enough time for the thermostat to open.
I've never heard this method described before, yet is seems fairly obvious to me (let the water pump drive the coolant, and any bubbles trapped in it, through the system, and out the bleed hole). Is there some huge drawback I'm overlookiing? One concern I have it that the system wouldn't be pressurized, since the radiator cap would be off during the procedure, which would allow the water to boil at a lower temperature. Is this a show-stopper? If so, can anyone think of a better way to ensure that I've exorcised all of the air from the system? Thanks!
As a quick recap, my problem is a lack of coolant flow back to the radiator, and I've ruled out the thermostat, water pump, clogged radiator, and collapsed hoses. The leaves air trapped in the passages, and passages clogged with some other foreign matter. Since attacking the former is free, I wanted to run something by everybody.
I'm skeptical that the standard method of pressurizing the system, and cracking the bleed screw open, will remove air pockets trapped in the bowels of the cooling system, at least without making a huge mess all over my engine and garage floor; I think I need stronger medicine. So here's what I'm thinking:
1. Open the heater
2. Replace the bleeder screw with a fitting, and attaching a clear tube to the end of the fitting. Run the end of the tube into a bucket.
3. Open the radiator cap, insert a funnel, and have a gallon of antifreeze (yes, glycol-free) and DI water mix on the ready.
4. Turn on the engine, and watch the coolant as it drains out the fitting and through the hose
5. As the coolant level in the reservoir drops, fill it with the fresh coolant. Never let the reservoir run dry!
Continue until there isn't a trace of an air bubble coming through the hose. Allow enough time for the thermostat to open.
I've never heard this method described before, yet is seems fairly obvious to me (let the water pump drive the coolant, and any bubbles trapped in it, through the system, and out the bleed hole). Is there some huge drawback I'm overlookiing? One concern I have it that the system wouldn't be pressurized, since the radiator cap would be off during the procedure, which would allow the water to boil at a lower temperature. Is this a show-stopper? If so, can anyone think of a better way to ensure that I've exorcised all of the air from the system? Thanks!
(This post was last modified: 06-10-2008, 08:38 PM by Cloud9...68.)