The Stovebolt Site Forums The Shop Area Engine Shop Engine noise

I know this is not a stovebolt 6, but I need input from you engine gurus out there. The engine is a 2.5L overhead valve 4 cylinder in a 1995 Jeep Wrangler with 104,000 miles. There was heavy sludge under the valve cover, cleaned out. After the engine has warmed up and then shut off there is a ticking noise coming from the rocker arms. If the rocker arm is down and the valve open you can actually feel the rocker arm moving up and down making the ticking sound. Does not do it on the closed valves, but it will happen on any of the rocker arm/valves if that particular one is down/open. I never saw an engine do this before. The engine does have lifters and push rods. HELP!!!!

Rick

Lawnmower sized engine questions would receive more attention in the Greasy Spoon.

Could it be the hydraulic lifters leaking down?

The first thing to do is an oil pressure check. If that's good (30 PSI or more) try a flush with one of the commercial engine cleaners or a quart or two of Diesel fuel. Don't rev the engine or drive the car with the flush onboard.
Jerry

Oil pressure is 40 psi. Jerry, how long does the engine have to run with the cleaner/diesel fuel in it? Idle, faster idle?

Thanks
Rick

Update

Installed new push rods, engine flushed, new oil filter, 10w40 oil. Problem solved. Most of the push rods were completely plugged with sludge. I'm assuming that due to the plugged push rods, and the lifters in the up position, caused excess pressure causing the rockers arms to tick when the engine was shut off and the pressure abated.

Rick

Good show! Sludge gets into some places where it's pretty hard to remove. I like to overfill a crankcase enough with solvent that the crankshaft counterweights and the big ends of the connecting rods splash the oil/solvent mix around like the agitator in a washing machine. 15-20 minutes at a fast idle is usually long enough to do a pretty good cleaning job. Just don't put any driving load on the rod bearings and drain the mix while it's good and hot.
Jerry