Radiator Cap making noise...got some questions

[Brad S.]

Lately since the weather has been warmer, 90's & high humidity, my radiator cap has been making noise after I shut off the engine.
Cap is making chattering noises, kinda like the teeth chattering from cold weather or scary movie...
It'll make about 4-5 chatters, then quit, then about 10 minutes later does it again.
Realize that coolant is traveling thru the overflow line.
The coolant tank is full and haven't overheated the engine, so coolant level is ok.
But does this mean the cap needs to be replaced??
The engine temp runs between the "r" & "m" on the temp gauge.
Thanks guys.

 

[OLDBULL8]

The engine always gets hotter when shut off, no coolant flowing. Your cap is working as it should. Cap should be a 13 Lb., some use a 16 Lb. The overflo reservor should be up to the Max prefill line when cold, overflo tube from cap to reservor should be at the bottom

Next time you go to start a cold engine, check the reservor, engine should have sucked some coolant back in.

 

[IDIoit]

check the rubber seals on the cap.
if there nice and flexible, youre good
if there hard, brittle and or cracked, its donski.

i always keep a new 13 lbs cap on hand, there cheap.