Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

are these good compression readings?

 
  #1  
Old 04-12-2016, 05:01 PM
Christopher Layton
Christopher Layton is offline
Senior User
Thread Starter
Join Date: Aug 2015
Posts: 120
Christopher Layton is starting off with a positive reputation.
are these good compression readings?

Just ran a dry compression test after warming up the engine (trying to troubleshoot why it idles a little rough)
1990 F350 7.5L (460) FI

Are these considered good readings?

Cylinder
1: 140
2: 139
3: 140
4: 139
5: 140
6: 145
7: 145
8: 150
 
  #2  
Old 04-12-2016, 05:36 PM
bmxerbrett's Avatar
bmxerbrett
bmxerbrett is offline
Junior User
Join Date: Dec 2005
Posts: 98
bmxerbrett is starting off with a positive reputation.
Those all look good to me. You can check the rings by putting a small amount of oil in each cylinder through the spark plug and recheck compression. If it shoots up the rings are worn.
 
  #3  
Old 04-12-2016, 11:39 PM
82F100SWB's Avatar
82F100SWB
82F100SWB is offline
Post Fiend
Join Date: Jan 2000
Location: Dryden, ON, Canada
Posts: 5,326
82F100SWB has a very good reputation on FTE.82F100SWB has a very good reputation on FTE.82F100SWB has a very good reputation on FTE.
You are well within the 10% variance that is considered good and those numbers are pretty decent for a stock engine.
 
  #4  
Old 04-13-2016, 12:03 PM
Christopher Layton
Christopher Layton is offline
Senior User
Thread Starter
Join Date: Aug 2015
Posts: 120
Christopher Layton is starting off with a positive reputation.
As it turns out the problem wasn't the engine misfiring causing the vibration, it was the fan clutch that had gone out and the fan was vibrating heavily because it was not centered anymore due to the clutch being messed up. Picked up a new fan clutch from Autozone for $35 and the problem is solved. Runs perfect.
 
  #5  
Old 04-13-2016, 01:57 PM
justcruzin125
justcruzin125 is offline
Senior User
Join Date: May 2015
Location: Sonora,Ca
Posts: 282
justcruzin125 is gaining momentum as a positive member of FTE.
Originally Posted by Christopher Layton View Post
Just ran a dry compression test after warming up the engine (trying to troubleshoot why it idles a little rough)
1990 F350 7.5L (460) FI

Are these considered good readings?

Cylinder
1: 140
2: 139
3: 140
4: 139
5: 140
6: 145
7: 145
8: 150
How many miles are on your truck?
 
  #6  
Old 04-13-2016, 02:34 PM
Christopher Layton
Christopher Layton is offline
Senior User
Thread Starter
Join Date: Aug 2015
Posts: 120
Christopher Layton is starting off with a positive reputation.
Originally Posted by justcruzin125 View Post
How many miles are on your truck?
106,957 miles
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
SSStang
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
15
10-12-2017 01:16 PM
BeauF0RD
1973 - 1979 F-100 & Larger F-Series Trucks
2
05-02-2017 06:53 AM
F1Hunter
1961 - 1966 F-100 & Larger F-Series Trucks
8
03-13-2017 03:58 AM
TruckerATK
1957 - 1960 F100 & Larger F-Series Trucks
3
10-04-2016 04:31 PM
GuitarJesus
1987 - 1996 F150 & Larger F-Series Trucks
1
05-05-2016 07:28 PM


Thread Tools
Search this Thread
Quick Reply: are these good compression readings?


Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.