compression test
Thread Starter
|
Junior User
Joined: Jul 2005
Posts: 55
Likes: 0
From: Amanda,Ohio
compression test
ok I was able to get the compression test done tonight on my 98 f150 with a 4.6 romeo and here are the results...
cylinder 1= 150psi
cylinder 2= 50psi
cylinder 3= 150psi
cylinder 4= 150psi
cylinder 5= 150psi
cylinder 6= 0psi
cylinder 7= 150psi
cylinder 8 =150psi
I rounded to 150psi even though they ranged from 145 to 155...
Im not very experienced when it comes to the major internal parts of an engine...can someone school me real quick on why the 2 cylinders are not getting compression? <!--IBF.ATTACHMENT_197262--><!-- THE POST -->
cylinder 1= 150psi
cylinder 2= 50psi
cylinder 3= 150psi
cylinder 4= 150psi
cylinder 5= 150psi
cylinder 6= 0psi
cylinder 7= 150psi
cylinder 8 =150psi
I rounded to 150psi even though they ranged from 145 to 155...
Im not very experienced when it comes to the major internal parts of an engine...can someone school me real quick on why the 2 cylinders are not getting compression? <!--IBF.ATTACHMENT_197262--><!-- THE POST -->
Thread Starter
|
Junior User
Joined: Jul 2005
Posts: 55
Likes: 0
From: Amanda,Ohio
I just replaced my old motor with this 4.6...it has 90k on it and I never heard it run before i bought it...the guy told me it ran great before his car was totalled but it sat for over a year...
Junior User
Joined: Sep 2006
Posts: 92
Likes: 0
From: Sooke, B.C.
Sounds like stuck piston rings to me. You could try putting penetrating oil in the #2 and 6 cylinders through the spark plug holes and letting it sit for a day. Then turn it over with the plugs out to blow out any remaining pen oil. See if that helps your compression any.
New User
Joined: Sep 2007
Posts: 1
Likes: 0
Trending Topics
Thread Starter
|
Junior User
Joined: Jul 2005
Posts: 55
Likes: 0
From: Amanda,Ohio
Originally Posted by crzyamerican
Bent or stuck open valve?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Thread Starter
|
Junior User
Joined: Jul 2005
Posts: 55
Likes: 0
From: Amanda,Ohio
well i have a little good news....I left my mechanic a message this morning as to the results of the compression test...Im sure someone on this forum may have gave me this advice already but he instructed me to put a couple shots of oil in the cylinders that werent firing and then re-test...I did so and my #2 cylinder fired right up to 150psi...thats better than the previous reading of 50psi...I unhooked gauge and turned it over to push out the oil and retested again to get the 150psi reading...Im assuming either a valve or the piston/ring was froze up....now as for my #6 cylinder...it still reads 0psi after the oil...which my mechanic tells me that should rule out a ring and tells him its probably a stuck valve or fallen rocker....
Thread Starter
|
Junior User
Joined: Jul 2005
Posts: 55
Likes: 0
From: Amanda,Ohio
drivers side valve cover is off and guess what I found laying in the bottom of the #6 cyl valve body??? you guessed it...a rocker arm!!!! now to figure out how that little sucker goes back on.....
Thread Starter
|
Junior User
Joined: Jul 2005
Posts: 55
Likes: 0
From: Amanda,Ohio
Originally Posted by xjoedirt55x
that is a lot better than messing with rings. what about the other cylinder losing compression?
Thread
Thread Starter
Forum
Replies
Last Post
89f150billy
1987 - 1996 F150 & Larger F-Series Trucks
22
Jan 25, 2014 12:12 PM
PowerstrokeJunkie
1999 - 2003 7.3L Power Stroke Diesel
43
Apr 30, 2008 04:50 AM
macman85602
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
6
Dec 7, 2003 10:57 PM