Home
What's new
Latest activity
Authors
Store
Latest reviews
Search products
Forums
New posts
Search forums
What's new
New posts
New listings
New products
New profile posts
Latest activity
Members
Current visitors
New profile posts
Search profile posts
Log in
Register
Cart
Cart
Loading…
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Search titles only
By:
Menu
Log in
Register
Navigation
Install the app
Install
More options
Change style
Contact us
Close Menu
Forums
Mustang Forums
2011-2014 Mustangs
Engine/Tuning
Rebuild or Replace motor?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Silbult14" data-source="post: 16112321" data-attributes="member: 179221"><p>A leak down test can be quite useful, but the test equipment is more expensive than a simple compression tester. A leak down test also requires a source of compressed air which not everyone has. Since you can do a compression test I would start with that. Make sure you have all the plugs out and either remove the throttle body or block it wide open so there isn't any restriction and make sure the battery is fully charged so you have plenty of cranking power for all 8 cylinders. I don't know what the factory compression spec is, but ideally all cylinders should be within 10% of each other. Just for example, if # 8 is 120 psi and the other cylinders average 200 psi then clearly there is something wrong with #8. If this turns out to be the case I would squirt a tablespoon or so of clean heavy weight [ at least straight 30 weight ] motor oil in #8 and crank # 8 again and see if the pressure comes up significantly. If it does you probably have a ring seal problem. If it dosen't do much, one or more valves aren't sealing. Good luck and let us know what you find.</p></blockquote><p></p>
[QUOTE="Silbult14, post: 16112321, member: 179221"] A leak down test can be quite useful, but the test equipment is more expensive than a simple compression tester. A leak down test also requires a source of compressed air which not everyone has. Since you can do a compression test I would start with that. Make sure you have all the plugs out and either remove the throttle body or block it wide open so there isn't any restriction and make sure the battery is fully charged so you have plenty of cranking power for all 8 cylinders. I don't know what the factory compression spec is, but ideally all cylinders should be within 10% of each other. Just for example, if # 8 is 120 psi and the other cylinders average 200 psi then clearly there is something wrong with #8. If this turns out to be the case I would squirt a tablespoon or so of clean heavy weight [ at least straight 30 weight ] motor oil in #8 and crank # 8 again and see if the pressure comes up significantly. If it does you probably have a ring seal problem. If it dosen't do much, one or more valves aren't sealing. Good luck and let us know what you find. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Mustang Forums
2011-2014 Mustangs
Engine/Tuning
Rebuild or Replace motor?
Top