Well, a quick review: Two weeks ago I hydrolocked the jeep and right after I got it running again it had a tick noise. Sounds like too much valve lash on one valve. Took the cover off and checked tham all and didn't find anything that would cause the ticking. Even had it running with the cover off and couldn't tell where it was coming from so I figured it was either stretched rod bolts, or an egged out pistin pin hole causing the tick.

Well, it's been two weeks and it's still going. The tick hasn't changed, it always there. If it were a pistin/rod problem I would have figured it would have let go by now but it hasn't. It runs perfect as far as I can tell. Compression is great in all cylinders, and I took off the spark plug wires one at a time while it was running to see of the noise got quiter on any particular cylinder, it didn't. If it were a pistin/rod problem I would think it would get a little quieter when I pulled the sprak plug wire for that cylinder.

So that leads me back to the valvetrain or something I haven't considered yet. Any ideas? Thanks!

 

Really? Nobody?

 

maybe a lifter.

Diagnosing a noise over text is near impossible

 

maybe a lifter.

Diagnosing a noise over text is near impossible

 

maybe an exhaust manifold leak at one cylinder, that will cause a ticking sound.

 

Yeah, but those get louder the more you increase the load on the engine. My noise does not, it is the same loudness no matter what the load or RPM of the engine. It gets faster with engine RPM, but not any louder.

I'll try to get a video with sounds of it this weekend and post it to YouTube so you can all hear it for yourselves.

 

Ok, I have figured something out at least. I have narrowed it down to the valvetrain. It's NOT a rod knock and here's how I know. If it were Rod/pistin/piston pin related it would knock twice per every rotation of the engine, once on the up stroke, and once on the down stroke. Now if it were a lifter/rocker arm/push rod issue it would only knock once every other rotation of the engine. So, by couting the number of knocks per minute at idle I can determine if it's rod related (twice as many knocks as engine RPM) or valvetrain related (Half as many knocks as engine RPM). I counted them and got about 300 knocks per minute at an idle speed of 600 RPM. That tells me at least that it's in the valvetrain which is good news. Now I just need to figure out WHERE in the valve train it is. My guess would be a lifter because everything else looked fine. If I ever get a day off I'll try to find out.