low compression

1996 FORD F-150
150,000 MILES • 5.0L • V8 • 4WD • AUTOMATIC
Avatar
GRINDY
  • MEMBER
  • 1 POST
my truck quit while driving. had been running rough. checked and found spark and had fuel at rail. tried starting fluid but would not hit. pulled timing cover and chain was loose. changed timing set but compression still low.
Mar 10, 2018 at 1:06 PM
Avatar
MHPAUTOS
  • ✓Experienced Mechanic
  • 31,937 POSTS
you will have to determine if it is rings or valves causing the low compression, a quick check is a wet and dry comp test, do a dry (normal comp test and record readings, for cyl that are low, add a small amount of oil to that cylinder just a few squirts from an oil can, enough to seal the top rings, re check comp, if the reading increases considerably the problem will be rings if no the valves are leaking.
Mar 10, 2018 at 5:47 PM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle