I have a light knocking sound coming from my engine only at idle and goes away when i press on the gas. I don't ever hear it any other time even when i have it at a high idle or accelerating. It's very strong engine and sounds very good unless its idling. I just bought the truck today from a old German guy 72 years old and he said he babied it and never got into it . in fact he has changed the oil every 2000 miles. I have no check engine lights at all and It seems to run great. It has 120124 miles on it. I was thinking it could be carboned up since that older guy drove it so light. If someone can help i just don't want to drive it if its something internal and blow my engine. Thanks a lot for any advice i can get. And also thanks for this great site!

 

I have the same exact truck. I would run some seafoam threw it and some injector cleaner and see if that helps. These engines get a little bit of lifter tick, mines the most noticeable in winter.

You only have 120k on it so its probably just carboned up.

 

ok i will try it! btw whats foam?

 

Welcome to FTE.

Could be a number of things & carbon deposits may be a good first guess, as I too have/had CCDI (Combustion Chamber Deposit Interferece) knock problems with my 99 4.0L.

Ford has a decarbon TSB out for the 4.0L & a link to it is in the "Tech Info" thread atop this forums thread listing page. lots o other good info there too.

I've found that running most of the current tank of gas out, then adding a Chevron 20oz Techron Concentrate Plus treatment at the pump, before filling up with Chevron, Texaco, or CalTex gas, then doing the 3500 rpm for 3 miles spirited driving/blow it out portion of Fords decarbon TSB during the treated tank & running most of the treated tank out, will clean mine out.
Then using Chevron, Texaco, or Caltex gas afterward, will keep my CCDI in check.

If you choose to do Fords decarbon proceedure, with the three cans of PM-1, you'll need to change the oil, filter & plugs afterward, which gets kind of expensive.

The Dealer did this dearbon TSB under warranty for me, but it didn't last, so I sorta developed my own decarb proceedure using Fords blow it out part of the TSB, along with the 20oz Techron & Chevron fuels, which already have Techron in them, so this will raise the Techron treat rate 10X above pump gas & will usually give results in one tank, without having to change oil, filter, or plugs afterward!!!!!

If the oil & filter have been changed lately, it may knock for a few days, if a certain oil & filter changing sequence isn't followed.
I believe because an air bubble gets trapped somewhere in the oiling system & takes a few days to work itself out. Anyway thats the way it's been with mine.
I have to first drain the pan & without delay refill it. Then remove the oil filter & without delay install the completely prefilled filter, then disable the fuel pump & crank the engine to build oil pressue & prime & burp the oiling system, before starting it.
If I don't do this I'll get a marbel clacking type noise at idle for days, before it'll work itself out.

Or, you may have "Marble Noise", which sounds like metal marbles clacking together, especially at cold idle, but may go away, or not be as loud after warming up.
Anyway it's common on the pushrod 4.0L & can be caused by CCDI, or by piston wobble, because over the years Ford stroked the engine & the cut the piston skirts off & if they didn't pay close attention to piston & bore diameter tolerance buildup at the factory, we could get piston wobble.

But acording to Ford it won't shorten engine life, just aggrivate the heck out of us.

This wobble knock will be lower down on the engine block & may not go away after the engine warms up, like the CCDI does.
The CCDI clacking will be higher up & louder where the head meets the block.

Or it could be wrist pins, which I had on my brand new 99 4.0L & Ford replaced the engine on that one.

A whole bunch of possibilities for pondering, let us know what you find.

 

the oil change thing seems like what has happened! maybe because when i test drove the truck it didnt do it at all even at a idle! i checked this truck out good when i looked at it! then the day i went to go get it he changed the oil. and when i picked it up it was doing it! i like the method u developed and will try it just to clean it out non the less. thanks for the great info i feel better that my engine isnt toaste!

 

Sounds like it could be the oil change sequence thing, thats causing it to "marble".

If so, it might take anywhere from 3-4 days, to as long as two weeks for it to completely quiet down.

I've found I must first drain & refill the pan, then Completely fill the FL-1A filter & I do this by standing the filter up in it's box, to keep it clean & upright so it won't fall over.

Then with a screwdriver in the anti-drainback valve to hold it open so it can burp air out, while I slowly pour oil into the center hole & continue until the filter is completely full, right up to the sealing gasket.

We can do this on our 4.0L, because the filter is mounted inverted on this engine, so if we don't get crazy spinning it too fast when tightening it up, we won't sling any oil out.

Then there will be a minimum amount of air trapped in there to be burped out, when we crank the engine to prime the system, before starting it up.

The Techron decarb has worked well & lasts for me, especially if I continue using fuel with Techron in it to keep deposits in check & do regular TSB 3500 rpm accelerations, to keep the carbon cleaned out.

If it's a CCDI knock, it's because of poor factory tolerance control & build up, from deposits on the piston crowns & heads in the "squish zone" of our low emission engines, that allows the piston to make contact with the head through the carbon deposits.

This kind of knock is usually loudest at cold idle & goes away as the engine warms some & expands enough to give clearence in the squish zone.

So if we can keep combustion chamber deposits low, we can usually diminish or prevent the CCDI knock.

If we can find another go to fuel, with different ad pack chemistry, but whos fuel ad pack says it'll also remove combustion chamber deposits like Techron does & then switch between those two fuels every 1000 miles, or maybe every 6 months, or whenever CCDI returns, we may be able to use the two different fuel ad pack chemistries to clean each others deposits up & keep CCDI in check.

The frequency we'll need to switch fuels, or do a decarb treatment, will depend on the engine tolerance, carbon build up, how we drive & the fuels ad pack chemistry.

More engine knock thoughts for pondering.

Will be interesting to hear what you find & how it goes.

 

Ok i have chosen the sea foam option and will try that 1 first at the same time i have purchased the techron concentrate and will use that next. I will keep u posted as to my results and thanks for the welcome to the forum and all the help.

 

Im so glad u told me so when i do change the oil next time i wont have this terrible noise. I still chose to use the sea foam to clean it out anyways but thatnks a lot very good information.

 

OK, If you ingest the SeaFoam through a vacuum line, like the TSB says to do the PM-3 Decarb treatment, be careful not to give it too much too fast, such that you hydrolock the engine & bend something up.

Ingesting the SeaFoam through a vacuum line to quickly decarbon an engine will dirty up the oil & might foul the spark plugs & will call for changing the oil, filter & plugs, like when using the PM-3.

If you choose to use the Seafoam in the gas tank, like Techron is to be used, it won't foul up the oil or plugs & you won't run the risk of hydrolocking the engine. But this way it just takes a little longer to get the job done, but it's safer & less expensive.

DON'T use the SeaFoam & Techron at the same time & DON'T ingest the Techron through a vacuum line, it's to be used ONLY in the gas tank.

 

yup safer is better and put it in the tank! I will go through this tank full of gas in a day and a half! I will let u know if it gets better. I did notice for the first time when i started it that it took a while for the sound to come back like 3 or 4 minutes when before it started right at the begining of startup.

 

Well run most of the Seafoam treated tank out, with some spirited accelerations & maybe a 10-20 mile out & back road trip tossed in, before adding the Techron & do the same with it.

By then your engine should be all fresh & clean inside, from your Spring tonic treatment!!!! lol

 

ok! will do. i just made a 26 mile trip to work using the tranny without overdrive on! with some 2 and 3 minute 3000 plus rpm spurts i will do the same on my way home to. i have already notice a reduction of noise and now it itermitent :-)

 

can it actually work this quick its so very light now i can hardly hear it! i have to strain to hear it. wow! this is amazing stuff. can i actually use the tech stuff to or would that be hurting it on the next tank full of gas?

 

Run nearly all of the Seafoam out, then add the Techron at the prescribed oz/gallon treat rate at the pump before the next fill up & run most of the Techron out with some spirited driving.

If the noise was caused by the oil change sequence, it'll quiet down as you drive it & the cleaner uppers won't have anything to do with it.

If the noise is caused by CCDI, use both additives, as they both have different chemistries, they go after different deposits in different ways, so by the time you run both of them out, your intake valves, combustion chamber & fuel injectors should be about as clean a you can get them.

 

Does it sound a little bit like marbles rattling around?

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