Hey there- I noticed that after I drove my car around for a while and parked it that it would sound like it was boiling in the radiator. I popped the hood and saw the reservoir was full and there was lots of "boiling" going on in the engine. I read up on the situation and replaced the thermostat, the radiator cap and added more coolant today. I took it for a drive, but the same thing happens after I park the car. It still filled up the reservoir and sounds like the radiator or engine is boiling over. Any thoughts??? Thank you! Ray
mine did this till I replaced the water pump, also check your fan clutch make sure its working, otherwise it will not pull enough air through the radiator to cool what is there..
if engine is hot, fan should be running, if you rev it up it will speed up and blow more air, if you are sitting in the car and shut it off, it shouldn't freewheel, it should stop shortly after engine stops.
should be on emissions sticker, I believe they called out at 4 degrees btdc, o ran mine at about 10 our so without issue. with vacuum disconnected to distributor...
Just a thought, I had a warped head on a 1968 350 Buick which was sucking air and pushing coolant out the overflow. Not a horrible problem but I had to take the heads to the machine shop. Sounded like what you said, you heard boiling sound etc. My car was running hot at the time too.
I read that I may have air bubbles in my coolant system and to take the radiator cap off and run the engine to get the bubbles out. It also said to turn the heat on. When the engine was running with the heat on I noticed that the coolant would slowly rise and flow out of the radiator. Should this be happening? I thought the coolant would drop in the radiator. Thanks for any advice!
What I meant by back flushing is removing the two hoses that go into the heater core and use a waterhose with a nozzle and spray water through each side of the hoses. Sometimes these hoses will clog up preventing the water from circulating correctly. I was having the same problem with my LeSabre and it hasnt ran hot since.
Your coolant will expand as it heats up, so that's normal. If the motor has been properly bled off, the coolant should expand into the overflow can. If the car runs too hot and has a potential pressure leak internally (usually a head gasket issue) it'll sound like it's boiling off just after shut-down. Do the hoses collapse into themselves once the car has been shut off, indicating a potential pressure loss? If you're still in the process of bleeding it off, the coolant will rise until the trapped air bubble finally rises to the top, then the level will drop dramatically. And yes, this will make a mess of your driveway until this happens.
How would I know if it had a blown head gasket? I don't see anything in the oil or any smoke coming from the exhaust. And no, the hoses do not collapse. Thanks!
The fastest way to see if your head gasket is gone is to check for an over-pressurization of the cooling system. Run the car with the rad cap off, and look for bubbling (like a soda) coming up through the coolant. If the gasket is badly gone or there's a crack in the head, the coolant will blow out of the rad like a geyser. (ask me how I know) And yeah, start the car "cold" and warm it up. Don't try this with a hot system or you're liable to get burned. Any over-pressurization of the cooling system will usually cause a thermostat failure as well. The thermostat will usually stick open. If there's no evidence of any compression gasses coming through the cooling side, check the oil; if it's grey and milky, = head gasket. If this is the case, do not run the engine again, you'll tear out the entire bearing train if you run it for too long with "wet" oil.
Hi 66- No bubbling coming out of the radiator. I wonder if it is the water pump. I have not seen any drips coming from the weep hole... it is all very odd. Thank you- Ray
It might be the water pump; - but I can't see it being the primary cause if it doesn't leak. If the clutch fan checks out, and the rad cap is of the proper spec and pressure, then I'd hook up a temp gauge and see if it is running cool enough while driving before going any further. If the car runs cool, or within spec, then I'd probably just let it go; - you've a minute leak somewhere, probably the heater core, that will allow the pressure to escape more rapidly than it should. That said, if the car runs hot, then there is a problem. Check oil presssure, if it's low, then that's why it's probably running hot and overpowering your cooling system. So; Check clutch fan, check for obvious leaks, check rad cap specs, then check the rad for pluggage, check the heater core for leaks or a plug. It might be worth it to get the whole system back-flushed. To check a water pump that could be losing its prime; Shut off engine. Grasp the pulley, and give it a wiggle. If there is any movement along the shaft, ie, the pulley feels "loose", then chances are your pump is just about shot. It'll suck air, and it'll lose its prime. It'll also vent pressure, which should be accompanied by a leak (or will eventually degenerate to one). If there's anything coming from the weep-hole along the pump shaft, then it's time to replace the pump. If it's the original cooling ssytem and pump, it may well be time. If the pump is struggling, it may cavitate, and that will degrade the timing cover as well as the impellor. If the cover gets pitted, then it won't matter what you do, it'll always work below par. Just something to think about. Hope this helps...
