Expansion tank Cap
Thread Starter
Instructor
Joined: May 2021
Posts: 187
Likes: 67
From: Long Island - New York
Expansion tank Cap
I'm in the process of replacing my thermostat in a 04 Z06. Was curious about the expansion tank cap. Mine is a 15lbs cap but I see the replacements are 18psi.
Why the change? I know this increases the boiling point of the dexcool but I never had an issue with overheating. With a 20 year old car, I figured it may be a good idea to put a new one on but am reluctant to increase the pressure.
Am I overthinking this or should I try to find a 15lbs cap?
Thoughts?
Why the change? I know this increases the boiling point of the dexcool but I never had an issue with overheating. With a 20 year old car, I figured it may be a good idea to put a new one on but am reluctant to increase the pressure.
Am I overthinking this or should I try to find a 15lbs cap?
Thoughts?
Melting Slicks
Joined: Jul 2004
Posts: 3,294
Likes: 480
From: Brea CA
GM changed the spec during the C5 production run. Your 2004 should have had the 18lb cap. You are good to go with the 18lb cap.
Also inspect the expansion tank, those are known to leak at the seams.
Gary
Also inspect the expansion tank, those are known to leak at the seams.
Gary
Thread Starter
Instructor
Joined: May 2021
Posts: 187
Likes: 67
From: Long Island - New York
While I understand GM changed the cap, I don't see a reason to as it never previously overheated and adding additional pressure may cause some other unwanted issues.
I think I will keep it at 15lbs for now.
Thank you both for your input.
Mark
