Loud Ticking F134

A buddy of mine just bought a 52? M38a1. Nice barn find. PO parked it 8 years ago. Anyway, he got it running, but there is a very loud ticking noise. Definately not a knock. Stuck valve? Where shoud we start? I'm not sure what to search for. Already searched ticking noise.

 

Might be, or a bad valve adjustment. Location can be a big clue.

Use a mechanics stethoscope. Or use a long rod or screwdriver with your thumb wrapped over the end and held to the ear. (BEWARE FAN AND OTHER MOVING PARTS!) Hold it against different parts of the engine. It's like x-ray hearing.

"Ticking" noises can possibly be exhaust manifold gasket leaks. Try the trick above but with a hollow tube, to locate.

 

My 231 V6 had a loud ticking noise even if its not the 4 cyclinder. I changed the lifters...still there, removed the heat riser flapper, changed the exhaust manifold gasket...still there. Shut down the motor and removed plug wires starting with #2, 4, 6 no change, still ticking. Removed the valve covers and started, and the valve train all looked the same from cyclinder to cyclinder. Checked compression and the #4 cyclinder was down 30+ compaired to the rest.
I go and pick up the motor from the machine shop in the a.m., and my loud ticking was a spun rod bearing & a twisted rod. I think they say if you remove a plug wire at a time and restart, if the noise goes away then it most likely will be valves. I would also suggest what PeteL said as well.

 

Thanks guys, We'll try pulling the plug wires one at a time. Hope he doesn't have to pull the motor....but then again, we'll learn something

 

Might I suggest putting in one quart of Marvel Mystery Oil and run engine.. It will free up a lot of things. Worked very well for me and I use it in every engine I have. Drain out one quart and add the MMO..

 

Could be rod bearing or a lifter, you should probably tear it down for a rebuild anyways.

 

Rebuild? If this is a military jeep, it may have genuine low miles. DoD surplused them at about 25,000 miles.

 

Yeah, I would not jump to any conclusions. Check the compression and the oil pressure. A bad rod knock will affect the oil pressure, and sounds much different from a tick-tick-tick. A rod sounds more like hitting the side of the block with a soft-faced hammer.

Check the valve clearance - even if there is something broken in the valve train, it will show up as slop in the adjustment.

I expect the military manuals are available as a reprint - try searching on "the G" www.g503.com You could also use a civilian manual for most things http://thejeep.com/shop/TECH+MANUAL...%252F6+L%2526F+HEAD++JEEP+SERVICE+MANUAL.html

 

thats what mine was doing when i 1st got it.
it was loud and i was scared.:?
i adjusted them and it sounds great!

 

If it has an electric fuel pump that might be the culprit. My fuel pump ticks loudly for a while but eventually goes away