Originally Posted by stink
retired ford tech, Guys!!!! please do not overfill!!!! as stated the crank will pick up oil from pan and foam. This will also lead to broken pistons NOT GOOD. The slack adjusters for the cam and valves need ford semisynthetic 5w20 NOTHING ELSE If a full synthetic is used cam follower and cam damage can occure and yes I have repaired lots!!! and after testing oil, ford would not warrent repairs. Please read your owners manuals.
Please forgive the soap box but I have fixed many class A and C ford RV engines V8 and V10. The engines are very rugged if treated right and serviced regularly.
So what you are saying, we who've been using Mobil 1 5w30 full synthetic oil over the past number of years will be facing cam follower and cam damage?
Could you explain in detail what physically happens between the cam follower and cam from using full synthetic oil vs. semi-synthetic oil that results in the damage?
I can appreciate where oil viscosity may have an adverse effect on a cam follower and cam, but difficult to understand where the use of semi-synthetic vs. full synthetic would.
Our 2000 coach has the v10, and the owners manual spec'd 5w30 oil with no mention of a warning NOT to use full synthetic oil.
Later Ford issued a TSB calling for a change from 5w30 to 5w20 with the reason given as to improve fuel mileage which appeared to be miniscule.
We now have 75,000 miles on our engine and have used Mobil 1 5w30 full synthetic oil for 11 years changing oil and filter between 5 & 7K miles.
So far we've had no issues with the camtrain. Is there a time frame in which I can expect the failure you describe from using the full synthetic oil?
Would appreciate your thoughts on the matter, Thanks