ZX14GUY
New Member
- Joined
- April 29, 2010
- Messages
- 2
- Reaction score
- 0
- City, State
- Michigan
- Year, Model & Trim Level
- `07 Explorer Sport Trac
This engine has 127,000 mi. on it and on a cold start the driver side lifter(s) started tapping for first minute or so then they quieted down . This 4.6l 3valve has VCT on it. Did oil changes regularly (But used 10w40 - I worked as a Test Engineer 37 yrs in Dearborn Engine Testing lab and us engineers agreed that spec oil 5w20 was too thin, might just as well put in penetrating oil ,5w20 was used to improve CAFE numbers). Changed out all lifters (proper name is "Valve Lash Adjusters") and 5w20 oil/FL-820 filter. Now "brand new" on drivers side are still noisy during first minute or so on cold start up (sound like valve train was going to come out of valve cover). Right side valve train is dead quiet! I didn't work on this crummy engine program at Lab! My guess is there is a restriction of oil flow to lifters. Is VCT solenoid hampering oil flow? Does anyone have "Oil system circuit" blow up?? Thanks! Jim