Hi,
I have a 99 F150 4x4 5.4l with 81,xxx. When I start the truck in the morning, it has a bad knock. It sounds like a lifter but I am not sure. Once the motor warms up, the noise of the knock reduces drastically, for the most part goes away. When the truck is warmed up, the knock barely comes back under heavy load. The knock seems to only be prevelent at first startup of the day. I park the truck all day (10 hours) and when I leave work, start up the truck, the knock isn't there.

Any suggestions?

 

I just found this in another post.
Is this accurate?

"try a thicker oil... worn engines have larger gaps between parts, so to compensate for that, a thicker oil would be the benefit. this will save your engine down the line. i suggest 15w30 or 20w30. you can also run 10w40 but throw in a bottle of Lucas Oil treatment.. thos stuff is sticky and very thick, so it will stau in between larger gaps for a longer period of time, quieting or even silencing any type of engine-related startup noise. i've used both methods in the past and they work great. the thicker oil method is the cheapest, being that Lucas oil treatment is aroun $7/quart (you need one for everey 4 quarts of oil)

if you do go the lucas route, i suggest pre-heating it to allow it to flow easier cause it takes 2 years for it to spill out. a good thing to do when your at the very end, throw in a bottle of 10w40 inside the lucas bottle, mix it up a bit then throw it back into the crankcase.. that takes all the residue out and makes your money's worth. "

 

I completely disagree. Try using the proper oil (if you are not - your post does not indicate what you are using). These engines should get 5w-20 or 5w-30 at the most. There is no need to run such a thick oil. The thicker the oil the slower it gets to your engine vitals especially on a cold start. I would rather have the correctly spec'd oil in my crankcase with a Motorcraft filter. These engines are not from 40 years ago... Google seach stories of people who spun a bearing after using Lucas oil treatment. Not fun stuff. Why anyone would want to put something that thick in an engine is beyond me.

What you are hearing may be some piston slap which is normal for these engines and is not a cause for concern. Just out of curiosity what oil are you using and what filter?

 

I realized after I posted that I left out some vital information.

I run motorcraft synthetic blend 5w-20 with Fram filter. I burn about a qt per 1000 miles.

I live in the greater Seattle area so it doesn't get super cold at night. Most nights it gets down to about 40 in the winter.

 

I just found this too... Thoughts?

"Ø One of the most common causes of engine noise comes f rom the use of a poorly designed or incorrect oil filters. With these engines you must use a filter with an anti-drainback valve, preferably one which is made of silicone for durability and flexibility. If you use a filter without this type of valve, oil can drain out of the filter and on start up you get lifter rattle which is both annoying and potentially damaging to your engine. Always buy an S designated filter. In the opinion of some members, it was felt that Motorcraft 820S filters from Ford (made by Purolator) or Purolator branded filters among others are very good, while Fram filters should probably be avoided. "

 

The oil that you are using is good.
The Fram oil filters are not a quality product, in my opinion. They do spend a lot of $$ on advertising though.
I suggest you use the Motorcraft 820S oil filter, or whatever is the correct p/n.

 

I commend you on searching to find the answers for your dilemma. This time you came up with the correct one (may not solve your issue but it is a step in the right direction). Change out the filter with a Motorcraft one and see what happens.

My brother in law built up a 302 into a 347 and it knocked really bad that he thought that something internally was wrong and was mad that he spent thousands on a motor that was no good. I noticed the orange filter and just cringed. I said to change it out and even brought him a Motorcraft filter. He did and the knock never came back. Hopefully that was enough to turn him away from that nasty little orange devil.

Just because EVERYONE sells them and many people have used them for along time with no issues does not mean that they are a good filter for your application. Try out a new one and let everyone know what happens. Maybe this isn't the issue but you have to start somewhere. Sometimes the smaller cheaper places are a good place to start.

Good Luck!

 

The issue you are experiencing has to do with a "short" piston skirt on 5.4 pistons. It is very common to have a "knock" after start up and for the noise to go away as the engine warms. The problem is an annoyance and there is no corrective action needed. You should be using 5w-20 and a decent filter.

 

if you've ever changed your own oil, you would notice that it momentarilly does the same thing that your hearing. the newer nodel f150's are the worst I think.