Bottom end "knock", what could be the issue?

[2000Ranger3.slo]

Has anyone ever used Seafoam injector cleaner? Well, the other night i was bored and decied to clean my MAF, IAC, throttle body real good and took about half the bottle of seafoam sucked into the brake booster line. turned the engine off for about 5 minutes and cranked it back up (that was kind of a task, gotta give it some throttle) and let it smoke pretty good for about 10 minutes. After that i drove it around the block a couple times. Not sure if it was coincidence but the knsock/tapping i have been hearing has gotten ALOT better and my truck runs a lot smoother- like i said coincidence or not whatever i did out of all that has reduced the noise alot. Give it try if you have this issue, seafoam could be the answer haha. If you try it and it helps post back-

 

[fourwheelford]

Yeah been there done that, I have sea foamed the intake, cleaned the maf, cleaned the TB, sea foamed the crankcase, run injector cleaner every couple thousand miles, change my oil before it needs it and the noise persists. I am at the point of just driving it and if it blows up putting a new motor in it. If 5 percent of all the rangers out there have this problem it would figure that I would get one of them. Of course 5 percent is an estimate.

 

[2000Ranger3.slo]

Yea, im gonna put some better plugs in her now- the noise might have gotten a little better but then again my truck is idling around 1100rpm now so maybe i just cant hear it as much now. I dont know, still runs strong gotta love it!

 

[lorenambrose]

This is wierd. I have a similar sound. I only hear it in the cab at slightly above idle, (900-1000) RPMs. My mech thought torque converter since it was most repeatable in gear with the brakes on. My truck runs great but the noise scares the crap out of me since I drive 1 hour each way to work. The noise is hard to describe in words, but it is a droaning, worn bearing sort of sound. Mine started after a catastrophic overheat that resulted in heads and head gaskets. It has been to the Ford dealership, Tranny shop, and the CarMax service center and nobody can figure it out.


Does this sound like what you guys are experiencing?

 

[bcost882]

I just gave up on it i make sure it doesnt really change but I dont think it has anything to do with automatic or manual transmission specific parts. it is either internal transmission gears or resonating engine.

 

[lorenambrose]

I am begining to think it might be in the catalytic converter. Then I might be grasping for straws.

 

[fourwheelford]

I thought it was a cat first and then maybe an exhaust leak but it is not far enough back to be the cat and to sharp to be a leak. Its annoying and embarassing, especially when your in a drive though or a drive up atm and your truck is clicking like that. My rig is in pretty good shape and I work hard to keep it that way and I baby the hell out of it but this is getting old.

 

[lorenambrose]

After driving the truck for 50 miles or so the noise is almost gone. The shop said the tq converter did not fix the issue. As I thought about it I had the tranny flushed at a local little shop and I think they used the wrong fluid. Reason being is the dealership put TWO tq converters on and nothing was fixed but a whole lot of fluid had to be changed.

 

[2000Ranger3.slo]

Like fourwheel said, it is annoying and embarassing... I wonder how its gonna be if i decide to sell it one day- Someone looking at it and go to crank it up and hear that clicking noise... Most peoples first though is "wow, your engine is knocking, sucks for you." Atleast i'm not the only one though...im sure one day someone might find the answer. I try to ignore it now, over the years it hasnt got worse or affected the performance, still cranks right up and gets me where I wanna go--

 

[fourwheelford]

Yeah I also changed my tranny fluid, but I didn't drain the torque convertor I may do that.

 

[FL_forlife33]

i think i have same noise

i have a 99, with the 3.0. manual tranny... i always described it as almost sounding like a diesel engine. i've crawled under mine and it sounds exactly liike it's coming from right behind the oil pan, or between motor and tranny. the noise is kind of like a khuk khuk khuk khuk khuk sound, right?
i've been worried about it ever since i've had the truck, i guess there's no solution?

 

[lorenambrose]

Well unlike some, I could hear the noise only in the cab, at idle about 950rpms. The fix............................

Belt tensioner. Yep it was and Autozone unit and they use a flat bar spring wound around itself. The have a tendency to slip out of place and it sets up a harmonic in the engine block. Bought a NAPA OEM tensioner and all is wisper quiet. I am not sure about the noise you guys are experiencing but a 10 dollar stethoscope was all that was needed.

I do suggest removing the belt and starting the engine and checking for the noise. If it is gone, then you will know the noise is something belt driven. Also belt driven items do not always squeal or chirp when they fail.

 

[FL_forlife33]

yea

yea, i already replaced my belt tensioner because i went to change the belt and i ended up stripping out the screw because the spring in the old tensioner was seized, and it wouldn't turn.

so i have a new tensioner in there, and i still have the noise. it sounds exactly like i have a little mini diesel engine, it just khuk khuk khuk khuks along at idle. i haven't tried a stethoscope, i may do that.