crazy knocking sound

[EXPLORE THIS]

help me please.


i have a 1992 eddie bower / with a 4.0. over all the truck is rockin, but i have a sound that goes, tap tap tap tap , then its quiet for a few seconds, then back to the tap tap tap tap. i have had numberous machanics look it over. but thay are all lost. lots said lifters as the sound is real loud near where the last plug is on the passanger side / near firewall. i have tried slick 50, stp ,engine restore, duralube, it did not do jack. hurd it might be tranny related, so i flushed the tranny, all new fluids, also additive, nogo again, i removed the shield around the catalitic converter, did not help. i crawled under as the truck was running yeaster day trying to tackle this issue and it sounds like its comming from where the tranny and the engine go together. vary loud. i know that when i use my front 4x4 it makes the occasional knocking sound / not sure if its related. if anyone has any idea please let me know. thank you in advance

 

[Muskrat]

Does it start just a little after you start the truck? I think I have the same problem, my friend said my cat is going bad, I had is submerged in mud. It makes a poping sound, and the engine surges a little. My vitales seem all right, so this is pointing to my cat, I think. He said that the water I got in it is prob. boiling. Time for a new cat, I think.

 

[EXPLORE THIS]

thanks, more info, it also causes my r.p.m's to flex. it goes between 1000 and 1500. happens in all modes, park, drive, reverse,2,1, dont make a difference. sounds really like something where the tranny attaches to the engine. i know that a few months ago i have a vacume piece replaced on the tranny, not really sure what the part is as im not a engine person

 

[Raceit]

It's your lifters.

I know the exact sound you're talking about. Plus mine started on the back passenger side too. It will only get worse and if not repaired will eventually bend valves or worse.

Here's the write up I did that's on the front page...

http://www.explorer4x4.com/lifters/lifters.htm

The only way to fix the sound is replace the all the lifters, all the push rods, and both rocker arm assymblies. All that needs to be replaced since everything "wears" together.

 

[dmasini]

I have the same knocking sound on my X but I have a 97 SOHC. I took it in to get serviced and they replaced the tensioner for the timing chain for the fluxing RPM problem but it didn't stop the ticking noise. I cleaned the MAF and reset the computer but it didn't work. Could lifters be the same problem on mine?

 

[Raceit]

Doubtful. The SOHC's have different problems all together. My friend had a '99 Mazda B4000, it had the SOHC 4.0L in it. It "knocked" all the time. The dealership just said it was normal. Needless to say he's done with Ford products. I don't blame him.

 

[dmasini]

Yeah, I've been reading a lot about how the SOHC's have this problem. I just find it hard to believe that their isn't some way to fix it. Oh well, it still drives fine and all but it sounds like $hit. I guess if you want more HP it comes with a price.

 

[Raceit]

Have you tried the higher octane gas?

Also here in the midwest starting about an month ago we have a very high humidity. It can get up to 90% and some time 100% without raining. (It's great to live here!) Anyways I've developed a theroy that around this time of year engines around here will have a better chance to knock since there is so much less oxygen and more moisture in the air.

 

[dmasini]

The humidity factor is a good point. I never thought of that... I first recognized the sound around Feb. but only in first and second gears after that it was fine. Now that it's summer it has gotten a lot worse so that is probably a factor.

As far as the higher octane problem, I really really don't want to start paying more for gas.
But I might try it just to see. I would have to reset the computer again right?

 

[Raceit]

You won't have to reset the computer or anything, but I'd try 3 full tanks of the highest octane gas you can find.