Originally Posted by pawpaw

Just rememberd 3 more things about knocking in my OHV 4.0L.

I tried a tank of 94 octane, no change.

I tried 10W-30, for one summer OCI, no change.

Last week I changed the 4.0L's oil & forgot part of my routene, that if I don't follow, will cause plenty of rattle/marble noise, that takes days to go away, after an oil change.

I must first quickly drain & without delay, refill the oil sump.

Then with the new oil filter completely pre-filled, without delay, change the filter.

Then disable the fuel pump & ignition, so the engine won't start, then crank the engine for 10-15 seconds to re-prime the oil pump & build oil pressure & burp any remaining air bubble from the system.

If I don't do this routene during an oil change, it'll begin to knock/rattle/marble, at idle, about 25 seconds after restarting & continue this idle only racket, for days, until it slowly goes away.

After I did the first oil change, it knocked/marbled/ratteled at idle, for two weeks, before quieting down.

I've never had an engine that was so danged persnickety about the way an oil change must be done.

There are others on this forum with the OHV 4.0L, that have the same problem, after an oil change.

Scared the heck out of me, the first time it happened.

Don't know that I've heard of the 3.0L doing this, after an oil change, but just a thought, in case any of you (especially OHV 4.0L folks) expierence knock/rattle/marble noise problems after an oil change!!!!!

So the only way I've found to be able to control my OHV 4.0L noises, is to control the combustion chamber deposit load & be persnickety about following my oil change routene!!!!!

Just some more engine noise pieces, to see if they may fit your noise puzzle!!!!!

Originally Posted by pawpaw

If either of you come to believe carbon deposits may be your knock problem, then read through the fllowing posts, on the Decarb link, from our "Tech Info"thread, located atop the forums thread listing page.
https://www.ford-trucks.com/forums/1...0l-engine.html

I've found using Chevrons "Techron Concentate Plus", in a tank of Chevron, or Texaco gas, at the specified oz/gal treat rate listed on the container, along with periods of the "spirited" driving over 3600 rpm for 3 miles, part of the Decarbon TSB, works for me & I don't have to change the oil, filter & plugs, afterward, as called out in the TSB, when they run 3 cans of Motorcraft PM-3 through the engine.

So you might consider trying that, before doing the Ford TSB, using 3 cans of Motorcraft PM-3, per the TSB.

rickster51, it kinda sounds like you may have two noises here. One sure sounds like the CCDI I have, the other kinda makes me wonder if the fly wheel bolts are loose, or maybe the torque converter has problems, so use the broom handle as a listening device & try to pinpoint the noise area more closely.

cadriver, your 3.0l's cold knock sure sounds like my 4.0L's CCDI. With the broom handle, my knock was loudest at the head/block interface, so that kinda gave me the CCDI idea.

My replacement engine developed the problem slowly over time & not until 01, when Ford replaced the head gaskets & cleaned up the pistons & heads, was I certain that CCDI was the problem, because after the rework, I didn't have the CCDI cold knock for 18 months.

After it returned & The Dealer tried the Decarbon TSB, which only lasted a short time for me, did I do some research on the CCDI problem & decided to try the Techron Concentrate Plus & the blow-it-out, on a regular basis part of the TSB.

I also switch between at least two gasolines, that state they have an add pack that'll also remove combustion chamber deposits. Not all will. Some will clean the injectors & intake valves, but not the combustion chamber deposits.

Some will clean the injectors & intake valves, BUT add to the combustion chamber deposit load!!!!!

SO, as it takes about 1000 miles, or 5 tanks of gas, for one brands fuel addpack, to clean the others deposits, we need to switch between at least two different fuels every 1000 miles or so, to keep the deposits down. I swap fuel brands every 6 months, or more often if the CCDI returns.

Why not try running most of the gas you have in there out, then add the Techron & fill up with a tank Chevron, or Texaco, then do the "blow-it-out portion of the TSB several times during the treated tank & see if things improve. run most of the treated tank out.

The Techron specified treat rate, is 10X stronger than just that in a tank of gas.

Just some things to consider.

So guys, let us know what you find & do & how it turns out.