Question ..........after 10 minutes of engine running

[acemang]

I came home and opened hood. and had a weird noise that I have not heard before. I cannot explain the noise but I have a 10 second or so video of it that the sound comes out clearly. Am I allowed to post a video here, or how should I do to it get to board members to get opinions?


A little pre video info. Temp outside is 50 degrees. Engine temp was 175 at time of trip end. Motor is a cadillac 472.
EDIT: Here is youtube link: http://youtu.be/8cWmO_0_90Q

It doesn't sound to me like standard engine ticking noises that you hear after shutting down an engine.

[geezer#99]

Post it up.

[Ilike 72"s]

Those 472's are good quite engines. What do you mean by 10 minutes? On rebuild? Or transplant of a runner ?

[acemang]

Added youtube link

[acemang]

Sorry just took it to sons school to drop stuff off. No new work done to it recently. Just noticed a noise that was new.

[Hugh Mongus]

metal contracting?

[acemang]

its almost like water bubbling but not coming from radiator or hoses

[Ilike 72"s]

If way to low on water and the engine over heats and makes steam it will make a sound like that. Although you should see the hoses move and hear it even when engine is off --unless the thermostat is stuck closed. The other liquid is gas in the carb getting to hot. The last liquid is oil. If thats it your screwed.

[acemang]

Originally Posted by Ilike 72"s

If way to low on water and the engine over heats and makes steam it will make a sound like that. Although you should see the hoses move and hear it even when engine is off --unless the thermostat is stuck closed. The other liquid is gas in the carb getting to hot. The last liquid is oil. If thats it your screwed.

I think you nailed it with the thermostat. Its a 185 and I think it had not opened yet as the temp was 175, I am just a nervous nelly. I have plenty of radiator fluid water mix 50/50. Oil is not burnt and is clean. Im guessing that you are right on the money.

[derotoreut]

Sounds like thermal expansion/contraction of radiator.

[Ilike 72"s]

OR---the significant amount of energy within the engine associated with the intermolecular forces of the liquid state changing to steam at the expansion rate of 30600/18 At 100C .
Rrrrrrightttt.,,

[Milo's 72]

Almost sounds like the spring in the choke assembly moaning as it heats up.

[Steeveedee]

Sounds like bubbles in a steel tube, almost like a wind chime. Are any of the heater lines metal, with a little hose at each end? Could be air burbulating in the system.

[Willys47]

Originally Posted by Ilike 72"s

OR---the significant amount of energy within the engine associated with the intermolecular forces of the liquid state changing to steam at the expansion rate of 30600/18 At 100C .
Rrrrrrightttt.,,

No not quite but it does takes 970 btus of energy to change the liquid state to steam state, your going in the rite direction with your thinking

[bigmac73]

Originally Posted by Willys47

No not quite but it does takes 970 btus of energy to change the liquid state to steam state, your going in the rite direction with your thinking

are you baseing your BTU number off of atmosheric pressure at 14.7

remember the higher the pressure the more BTU required to boil

[Steeveedee]

Originally Posted by bigmac73

are you baseing your BTU number off of atmosheric pressure at 14.7

remember the higher the pressure the more BTU required to boil

The latent heat of vaporization is the same at any pressure. Raising the pressure simply raises the temperature at which vaporization occurs.

[swamp rat]

Originally Posted by derotoreut

Sounds like thermal expansion/contraction of radiator.

I agree thermal expansion/contraction, Question is where, radiator, or possibly in the exhaust system.

[acemang]

After some great tips on here, I headed back to my man cave aka garage and investigated. After an hour I figured out the issue. I needed to treat my engine like a baby and burp the radiator. Once I did that the noise has gone away. it could have gotten bad so Im glad I heard the noise in the first place. Thanks for all the tips and advice.