In my past owned vehicles, I would drop the oil/remove the filter. Next, I would add a new oil filter along with ~ 5 quarts of white kerosene and run the block for a minute or so. After this, I would remove/replace this oil filter, let the kerosene drip out to nothing and then add the oil. This oil flush has always been pretty dirty.

Would you do this procedure to a 4.6L block?

 

Absolutely no way. Those old school tricks can be deadly to modern engines.

 

Unforeseen side-effects may include:

Uncontrollable urge to drop sludge
Excessive piston ring wear
Timing guide and tensioner failure
Oil starvation
Lack of lubrication during and after flush
Failure of critical engine components
Significant other leaving you for having a busted truck
Erectile dysfunction

If you experience any of these symptoms, consult your mechanic right away as these may be signs of an epic fail.

Short version is that the risk isn't worth the benefit. If you have an engine that's badly sludged, the best you can do is an accelerated oil-change interval and a lot of highway driving.

 

Or do an AutoRX treatment. That's the only safe way to desludge an engine in my opinion. Follow their website instructions to the letter.

 

This post reminds me of a customer we had that wanted representation concerning his putting a bottle of Dawn in his new Hemi and then topping it off with water. Ran great for about a minute. Then the parts started coming out. I can't imagine how much damage an engine would incur with 5 qt of kerosene in it. About the same as the Dawn and water I would assume.

 

Use the correct oil and filter. Change it on time. Thats the best way to keep an engine clean..