Radiator overflow after shutdown
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,720
Likes: 19
From: Manhattan Beach Ca
Radiator overflow after shutdown
Working on getting the kinks out of my new 383. Even though the temp never reaches over 190, whenever I stop after driving for a minimum of 20 minutes or more, the radiator cap overflow releases around a quart of coolant onto the street. My cap is rated at 16 lbs.
What could be causing this and is 16 lb the right pressure for the cap?
What could be causing this and is 16 lb the right pressure for the cap?
Team Owner
Joined: Jan 2003
Posts: 21,234
Likes: 19
From: Freestate Corvette Club! Elkridge, MD
St. Jude Donor '17
Working on getting the kinks out of my new 383. Even though the temp never reaches over 190, whenever I stop after driving for a minimum of 20 minutes or more, the radiator cap overflow releases around a quart of coolant onto the street. My cap is rated at 16 lbs.
What could be causing this and is 16 lb the right pressure for the cap?
What could be causing this and is 16 lb the right pressure for the cap?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
What temp thermostat do you have in the engine? I would recommend going to a 180 deg. stat (if you have a 195 deg. unit installed now). Latent engine heat can cause the water temp to shoot up some when you shut the engine down. Also, if you have no recovery tank, you need to leave expansion space in the radiator. If relevant, try the stat swap; if that doesn't do it, add an expansion tank.
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,720
Likes: 19
From: Manhattan Beach Ca
Got the expansion tank. Sounds like what you're saying 7T1 that engine heat is building up after shutdown. I'm using a 160 since I used it before and like'd how it kept the temp down. I might try a 180 if this is still a problem.
How about the cap pressure rating?
How about the cap pressure rating?
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Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
That is an expansion tank. The absolute maximum you can fill it cold is half way up. Most cars prefer even less than that and will puke any extra. Doesn't mean that anything is wrong
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Your 160 deg. stat shouldn't be the problem....but since there is "boil over" after shutting down, I suspect it may be defective. Change the stat (160 or 180 deg.) and the radiator car; both are inexpensive fixes and good "first tries". If you still have a problem, there is something wrong in the cooling system allowing it to overheat (bad pump, blocked radiator, etc., etc.).
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,720
Likes: 19
From: Manhattan Beach Ca
Good sugestions. The temp gage never reads above 180-190 when hot which makes me wonder if the cap is bad. I see they make a 18 lb cap. Again mine is 16 lb. What is everyone else using?
