Engine Knock

[greenchevy]

my jeep sounds like this one

http://www.youtube.com/watch?v=K4aiP5b-j6I

i changed the lifters thinking that was it but after i put it all back together it still sounds like this. when you push on the gas it goes away after 2500 rpms. but when you let off you hear it bad. any ideas? it drives fine just really loud. when i took off the head to replace the lifters the cylinders looked ok. I just overhauled the engine not to long ago.

[LizardRunner]

Have you checked the valve springs and valve lash? That could make that noise. If you overhauled the motor I would check that, valves usually need adjusting at least once after inital startup of a rebuild.

[msmoorenburg]

Sounds like a rod bearing let go. Pull the oil filter off and cut it open ,and see if you have metal flakes in it.

[4.3LXJ]

When that one was revved, it sounded more like an exhaust leak at the header gasket to me. But sound was kind of crappy. But it would help if you had a sound recording of what yours was doing.

[steph74]

I am going to follow this thread.....
Mine does all kind of funky noises,,,,,,, the main one that sounded like that (and I am not saying that it was the same pb or that i solved it definitely) was reduced / by 1/increasing the idle rpm and 2/ using a heavier weight oil...

Once this stupid noise got reduced, I was able to enjoy all the other little noises that make driving a jeep so enjoyable....

anyway good luck in tracking your problem, I hope it is not too important

[bigjim350]

Guess it could be the ol loose coverter bolt, or cracked flex plate problem, but the one in the vid sounds like a rod knock.

[greenchevy]

the head got replaced by a new manufactured one a year ago with the overhaul. I didn't have any problems with the engine until maybe a month ago. it sounds like its coming from the number 5 or 6 piston. If it is a rod would i just replace the last 4 rods? or is there more to it. There isn't an adjustment for the valves. You just torque them down and they self adjust.Thanks for the help so far everyone.

[pvt.tadpolxj]

Hey man my engine was doing the same thing. I added a bottle of Rislone oil suppliment which has a very high count of ZINC & PHOSOHORUS in it and the result's are amazing, and I am Putting a quart of the Valvoline VR1 Racing oil into it very once in a while. I started with a quart of 20w50 to help lubricate everything real good. I do not want to add too much of the 20w50 or it will overheat. But you can get the VR1 in several wieght's...:patriot:

[bigjim350]

Well if its a rod knocking, its more than likely a worn or spun bearing. The rod is probably fine. You may be able to drop the oil pan, and yank out the crank and check the bearings. And if no damage was done to the crank or rods, throw new bearings in there. But when a bearing goes something usually gets scored, and some machine work is needed.

[greenchevy]

they are new bearings. replaced less then a year ago.

[pvt.tadpolxj]

Hey greenchevy be sure to drive your jeep a lot slower until you can get it to run a lot quieter. And take a good look at the motor oil warning thread in the technical forum....Pvt. Tadpolxj:patriot:

[greenchevy]

I'll add Rislone oil supplement and see what happens. still don't get what happen.

[greenchevy]

would i be better off using Rislone oil supplement or changing my oil to Valvoline vr1 racing oil 20w-50?

[toebee97]

they are new bearings. replaced less then a year ago.
That doesn't mean that isn't the problem, I've seen rod bearings go to hell in less than a week. All it takes is "oops, forgot to put assembly lube on one side of one bearing. Oh well it should be fine..."

If I were you I'd look anyway just to make sure, I mean if the oil supplement thing doesn't do the trick.

[greenchevy]

the rislone helped some. Yea i have to drop the oil pan and look at the bearings. If the bearings are bad I'm going to replace the crank and bearings.

[Jeepster19]

Sounds like a rod bearing for sure.Get a mechanics stethescope or a long screwdriver and put it on the area where you think the noise is coming from.You will be able to tell between a normal mechanical noise&one that sounds like something is wrong right away.I would start on top&work my way down.Start with the valve cover area to see if its a rocker arm,it could very easily be that too.Good luck and let us know what you find out,pics if you can.:camera:

[greenchevy]

From the valve cover you don't hear the noise almost at all. But under the car/ engine pan its loud.

[jeepxj95]

i had the same thing and sound. it was the torque converter bolts. i knew it when i was pulling out of taco bell and it wouldnt move. runs strong but no go.

[pvt.tadpolxj]

Just leave the Rislone in there for a good while and you will be surprised how it will keep on working to make it run quiet. This product will also start making your oil stick to your engine part's a little better...:patriot:

[wad_e]

Thats exactly what mine sounded like, and my #6 piston was broke all to hell. The skirt was in five big pieces in the oil pan.

[osfp]

Mine sounded like that and I thought it was a rod knock but it was torqure converter bolts loose. Just had the engine pulled down and the bearing were all good

[LizardRunner]

I'd check the torque coverter bolts first, easier to get to. If not there then you most likely have to pull the crank. don't wait till a rod is sticking out the side of your block to get around to it. That's a serious noise, now that I've listened to it three times, I would have to say spun or wiped out bearing. No amount of "magic lube" will fix it and the longer you wait the worse and more expensive it will be to fix correctly.