Hi all,
Have a 99 Ranger 4x4 with the 4.0 V-6 and automatic. 95,000 miles.
Over the last year or so its developed an engine rattle that sounds as though its coming from the back of the engine or maybe even the tranny. Its loadest at an idle, when engine is warm. The rattle is loudest while standing in the area of the either driver or passinger door. From under the hood the engine sounds fine, with all the noise that I mentioned above transfering out the back of the engine and underneath the truck. Many people have told me the truck sounds like a diesel! The truck has no fluid leaks nor burns any oil. I took off the serpintine belt and ran it for a minute or so and that made no difference. The truck runs great, except at very low speed between 5 and 20 MPH where the RPM's are low enough that you can hear the rattle. I've had it checked by two different mechancs, and while they can hear the noise and rattle, they cannot isolate where it is coming from.
Any ideas?

Thanks
Rick

BTW, new timing chain about a year ago.

 

I'm thinking either exhaust leak (check manifold to y-pipe connections and y-pipe to cat converters) or one of the exhaust sheilds has a bad weld. Sheilds are easy to check...just get under there and tap around the sheilds on the cat converters, pull them and generally make sure all the welds are good. Exhaust leaks aren't real easy to detect just standing outside the vehicle without inhaling said exhaust and dieing...but at low RPMs if you give it some gas (just above the lugging point) it will be quite noticable.

Welcome to FTE.

 

I've dealing with the same problem rattling sound on my 2000 v6 4x2 and can't find where's the exact location of the sound neither the shop
is not the cat or heat shield that's for sure, checked that already.
I don't know how's your sound but mine it's louder when cold, and it does not change with different change in rpms or depressing the clutc, the sound is coming somewhere between the clutch housing and engine , my guess the trany sinchros, that I know 4 sure is bad cuz grinds from 2nd to 3rd only, and you really need to push that stick to get it in first.

Had the trany checked out and they finally told me is the trany sinchros going bad but no to worry it can last many many thousand miles more , by the time i need to replace it the truck would be more than 100k, so I'm no wasting any dough in repairs not yet.

 

Thanks very much for the ideas guys! My mechanic spent over an hour with the rig on a rack. He is really thinking its something internal, but just can't get the noise isolated to any one area. He's been in the business for about 15 years and is quite frustated that he can't figure out exactly what the problem is. I might add that when driving at low speeds it almost sounds like an engine knock from inside the cab. And yet when you pop the hood and listen to engine it sounds perfectly smooth, with all the rattling noise going out the back side of the engine and under the truck.
If you think of anything else, I'm open to any ideas!
Thanks again.

 

Does the sound change in any way?
Does it get faster when driving?

 

The only way the sound changes is the fact that the warmer the engine gets, the loader the sound or rattle becomes. On a cold start in the morning, it takes about 30 to 60 seconds before the rattle starts. Once I bring the engine up to normal operating temp its quite loud. At speeds above approx 30 mph I can't hear it at all. I think the rattle is probably still there but with normal tire, engine and tranny noise I just can't hear it. The truck runs smooth, shifts smooth, etc. It just sounds like a diesel at idle, or driving slowly.
Thanks for any ideas you may have!

 

If it's engine noise, maybe it's piston slap, or wrist pins.

My 99 4.0L was delivered with a diesel knock, that was worse when hot & at low speeds. you could really hear it when driving alongside a wall.

The Dealer's Tech said it was wrist pins. Ford replaced the engine a month later.

Some of the pushrod 4.0L's also had piston slap problems, from factory tolerancing buildup problems, that I'm told, were exacerbated over the years, by the boring & stroking mods & removal of some of the piston's skirt, such that if the piston/bore fit weren't closely matched, the piston would "wobble" in the bore at the bottom of it's stroke, because so much skirt had been removed/designed out, over the years & it would wobble on the up stroke & make a diesel noise.

So they were telling me that there were two likely reasons for my all temp "diesel" knock, wrist pins, or piston slap.

There now is a TSB called "Marble Noise", on this piston slap problem, Ford will not replace the engine. They say there is no evidence of shortened engine life, on an engine with piston slap.

I found the similial soundng cold knock, "marble noise" my replacement engine developed, was due to CCDI (Combustion Chamber Deposit Interference) It occurs only when the engine is cold.

Apparently it occurs when, at the top of it's stroke, the piston crown contacts the head, through the deposits on the piston & head, in the "squish zone", until the engine warms a little & things expand enough to give clearance.

I've read it's not uncommon to have as little as 1 mm or less, clearance in the squish zone, so it doesn't take much in the way of deposits, to cause problems.

There is a engine decarbon prceedure out to help with CCDI.

I believe my CCDI is mainly due to poor factory control of tolerance buildup during assembly.

So if we have the piston slap, or CCDI problems, we're kinda stuck with them, but it doesn't affect engine life accoding to Ford.

So I've experienced three kinds of diesel sounding knock on my 99 4.0L. Wrist pin probles, piston slap & CCDI.

If it's in the engine, rig a stethoscope using a broom handle & with one end to your ear, place the other end to various places on the engine & tranny & see if you can isolate the area a little better for us.

Does the sound change if the tranny is in P, or N, rather than Drive?????

Did this oise come about after some event?????

 

Hey maybe that's it?
My 2000 Ranger 3.0 has that diesel knocking sound when cold and diminish after warm up, the colder it gets outside the louder it sound, and I can really hear it next to a wall or standing outside by the truck ,but not able to hear from the cab.

I already poured a whole can of Seafoam through the intake, didn't see that much smoke, and didn't fix the diesel knocking either, but strange to me is my truck has only 75k miles, not a big carbon build up problem this early?
But why I don't hear the sound go faster when give it gas in neutral if the pistons crown is hitting the head?
This is another mystery my shop could not figure out!

 

The sound is louder when the engine is in drive, rather then park or neutral. And its much worse when the engine is up to normal operating temp. This is something that has been coming on for a year or more, but not after any one event. Also I do have the engine "marbling". Have had that for maybe 3 years. Not too concerned about that, but the engine rattle has got me worried. Like I say the truck runs and shifts smooth on the highway. Its just at low speeds or idle that I hear the problem.
Thanks for the reply!

 

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.

 

Something you might want to try and see if the noise diminish or goes away.


My very experienced mechanic told me not to use 10w30 on this motor because it has pushrods, so he said to try 20w50, because mine does the sound in the morning when cold. I will change the oil and keep you update it.

 

The only way 20W50 may help your problem is if you're having oil pressure issues. You need to verify this with a mechanical gauge (the gauge on your dashboard is NOT really a gauge). If your oil pressure is good.. do NOT use 20W50.

Ford doesn't even recommend 10W30.. they recommend 5W30 at the thickest.

 

My 96 4x4 4.0 has the same knock, it has had it since I got it {bought it used}. Oil weight does not change it at all. I have run 5W20, 5W30, and 10W30 which I use now. Tried the decarbon procedure, didn't change it. I guess it's just the way it is. I will drive it till it stops running. Right now it runs fine uses no oil and has plenty if power. It has 156??? miles and counting.

 

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!!!!!

 

I'm begining to think the same thing!! The truck runs flawlessly, with no performance problems, no oil usage, and no other problems really. Just that damn knock/rattle/ marbling, or all three!

Thanks for the reply!