I'm sure you guys heard this a millon times. I'm told by ford dealer this is common and theres no quick fix. I have a 94 STX 4x4 4.0 5speed with about 140,000 on the clock that just started making what sounds like a a bad valve tap when cold, it goes away after it warms up. It's loud and very dissturbing. I also don't notice any loss of power when it's doing it. I tried turning the raido up louder but the noise is still there. Is there anything else I could try before I rip the motor down to replace lifters?

 

I had a '91 explorer 4.0l 5spd that had a nasty lifter tick when cold, and at times it would even try when warm. The PO who is a friend of mine, said he bought it with 80,000 on it making that sound, I bought the truck with 235,000 on it, and the engine was untouched. It's the curse of the Cologne series, the 2.9l was known for lifter tick, and the 4.0l was only marginally better. I think you're wise to fix it now, but replace the camshaft at the same time, or you'll get the noise back in short order. And I would recommend switching to an oil with good barrier lubrication, I'm considering switching to Shell Rotella, I forget which cam company is recommending this to combat excessive camshaft wear due to additive reduction in new API standard compliant motor oils, but the reasons are well explained if you do some research, try bobistheoilguy.com

 

My 99 4.0L has a problem that sounds like what you've described & my "cold only knock", is caused by CCDI (Combustion Chamber Deposit Interference)

If thats your problem, a good decarbon of the engine may fix her up.

I've been able to keep my CCDI cold knock in check by alternating using the two best performing gasolines with different addpacks, every 6 months.

There also is a decarbon TSB out, that some have had good results with, but imo it's messy & expensive, as you'll need to change the oil, oil filter & plugs afterward.
The Dealer performed this proceedure on my 99 4.0L, but it didn't cure the problem for long, but others have had better luck with it.

For me, a dose of Chevrons "Techron Concentrate Plus" in a tank of Chevron or Chevron/Texaco gas & the "rev the engine at or above 3600 rpm, for three miles regularly", part of the TSB, has worked for me over the past 6 years.

For me using the Techron, cleans the carbon out at a slower rate, without dirtying up the oil & plugs & I get lasting results switching gas brands every 6 months between the two best performing gasolines with different addpacks .

It takes about 5 tanks of gas, or 1000 mles of driving, for one brands fuel detergents, to remove the others deposits, so idealy we should swap brands every 5 tanks, or 1000 miles, but I've found that every 6 months works for me.

Anyway if you think maybe CCDI is your cold knock problem, read through this thread & see if any part of it seems to fit your puzzle. Hopefully you only have a carbon deposit problem.
https://www.ford-trucks.com/forums/s...hreadid=100739

Just some thoughts to ponder.
Let us know how it goes.

 

My 94 has the same cold engine tick. BUT! It is only noticable after an oil & filter change for aprox, 1,000 miles then it is not heard again until the next oil change.

When outside temp is around 35 and i start it cold it is quiet then 10 seconds of ticking then quiet. This goes on until its warm, It has done this for the last 3 years and hasn't gotten any worse or better, I have 189,000 miles on it now and tried everything suggested in all posts and have gotten rid of the accelration pinging but this cold intermitent tick after an oil change just won't go away.

Sounds as if this is the same as you are discribeing.

 

I'll try the CCDI cleaning first and see what happens. I also was told by a freind it could be caused by a weak spark from my coil pack. any thoughts on that?
But I'll clean the CCDI then see where it takes me. I'm starting to see a good excuse to buy a performance cam. thanks for the help I'll let you know what happens.

 

Rags I've had the engine noise for days, after a oil change too.

I discovered, if I first quickly drain the sump then refill it without delay, then with the new filter completely prefilled & ready to install, remove the old filter & without delay install the new prefilled one, then kill the fuel pump & crank the engine to build oil pressure & burp the system, it won't knock after an oil change.

If I reverse the process, by removing the filter first, then drain the pan, it'll knock every time, for days, before finally quieting down.

I know several others on FTE have the same problem with the pushrod 4.0L.

Maybe we are trapping air in a dead end some where, by letting it drain too long.
Or maybe letting it drain too long & not prefilling the filter, the oil pump looses it's prime & part of that big bubble of air in a empty filter gets pumped into a dead end some where & causes a drop in pressure.

Why it takes days to quiet down, is still a mystery to me & others, but by doing the oil change as I've outlined may help, give it a try & let us know how it goes.

 

pawpaw I don't mean to challenge you, just looking for more information.

I've previously heard that to decarbon the engine, you just needed to run it in a semi-hard acceleration to 3500 or so before shifting (or letting the auto shift). When did it become run it for three miles?

 

It became 3 miles at or above 3600 rpm, when Ford put it in the decarbon TSB!!!!!

Yup thats the kind of fix I like, rev the heck out of it, on a regular bass & all factory approved by Ford!!!!!

They want us to do this every day, to keep it cleaned out.

Wonder if maybe we should carry a copy of the TSB, just in case the officer doesn't believe us!!!!! lol

 

Thanks PawPaw, I will give that a try on the next change. Even though I didn't pre-Fill the oil filter this time I always disable the fuel pump and crank till guage moves. I like your thought about trapped air, but I wonder why it shuts up when it warms up, and then back to the ticking the next morning?

To me it sounds like it is coming from the timeing case cover? Wonder if its possible for the air to be trapped in the timing chain tensioner? If not mistaking it is operated by oil pressure? and could this ticking just be chain slap?

 

I don't know about the timing chain tensioner, I think what your referring to, is the tensioner cassett noise that was common on the 01 SHOC 4.0L, our pushrod 4.0L doesn't have the same setup up front.

For me, about 15-20 seconds after a oil change restart, mine was quiet, then slowly got noisey, you could hear it coming.

The noise sounded sorta like valve lifter rattle, or "marble noise", or maybe sorta like a mild diesel rap. It would only begin 15-20 seconds after start up, at idle & if you raised the rpm a little it would stop. This happened after the first oil change & scared the heck out of me, I thought I miscounted & was a qt or two low on that first oil change, because I too had become distracted in getting the factory installed filter off, man what a bear it was. The guy that installs them at the factory, must be named BUBBA or IVAN!!!! lol

Anyway it took about 4 days that first time, for it to stop the rattle at idle.
It was so loud, a Tacoma guy at the boat ramp, thought my Ranger had a DIESEL!!!!! lol

The Dealer couldn't figure it out, said they had never had one do that before. One of the old Tech's even suggested NOT filling the filter, if you can believe that!!!!!

This noise also sounds a lot like the CCDI induced, "marble noise" knock. It's easy to confuse the two.

For me, the CCDI knock always goes away after the engine warms up a little & will completely disappear after a good engine decarboning.

The idle rattle, after a oil change, will hang around for days, once for as long as two weeks, before disappearing, until the next oil & filter change.
Once it goes away, the engine is quiet as a church mouse!!!! Go figure!!!!!

I've even tried 10W-30 on one fill, no change.

The only positive reaction I've had, was to first quickly drain & refill the sump, (I even have the oil opened & ready to pour in), then quickly change the filter with a completely prefilled one, ready to install, then crank the engine to build oil pressure & burp the system.

I've had two brand new 4.0L pushrod engines do this!!!!! Talk about luck of the draw. Never before had a Ford engine knock on me, in fact never had a problem with ANY engine before this!!!!!

Just some more thoughts for pondering.

 

ok I think the CCDI was my problem. I used "run-rite" from pepboys. A four part kit, a can of throttle plate spray, a bottle of oil additive, a boddle of gas additive, and a bottle of induction cleaner that engine vaccum sucks in. then a set of double plaitnum plugs, new wires, and a full tank of ultra 94 gas and she purrs like a kitten. All for about $100 vs. cam and lifters for $650.
Thanks guys!

 

Good grief, sounds like you gave her a chemical enema, bet she's all fresh & clean inside now!!!!! lol

Good to hear all is well!!!!