This is going to be a very long thread sorry. Long story short looking for a ticking noise. 1990 XJ 4.0L AW4 makes really loud noise at start up. Also continues to tick for a little while after the engine is shut down. Clatter at higher rpms. Got sick of the noise and my leaky valve cover, so I decided to check some things out. Pulled the valve cover and while engine was ticking(shut off) felt rockers and could feel the tapping reverberating through the rockers and push rods, so I am immediately thinking lifters. Been using additives and different oil weights for a while now MMO Lucas nothing helps. I had to drop my oil pan to fix a few more leaks. So while I was in there I have been checking out the lower end. When I turned the engine over by hand to get a better look at a few of the piston rods and bearings. It starts that infernal ticking. So while its ticking I feel the lifters from the bottom side. I don't feel anything weird I thought it was lifters, and I thought I would feel the tap for sure. I keep feeling around while its ticking I can't find it. Sounds like the upper end. Could this be rocker arms, or push rods making this noise? Any other suggestions? I am so close to finding it. It's getting a rear main, oil pan gasket, high flow oil pump, and new bearings. Upon inspection bearings are toast. I have ruled it out as lower end it has to be upper. I inspected valve springs they looked and felt fine. Torque rocker bolts. The only other things I cam think of are push rods or rockers. possibly a valve, but I doubt it. has anyone ever had a noise like this. thanks.
My 87 and 89 have done this since I bought them.
It sounds like you are describing two different issues. One while the engine is cold, not having been started, and you just manually turn the crank by hand? Is that correct?
Or is after starting it, turning off before it gets hot, and then you turn the crank by hand?
Both of mine do it (tick with the engine off) after a short start up, still cold or hot. I always assumed it was the T-stat or exhaust creeking, but now you have me wondering.
Both of mine also use to make a racket at cold start up, but I solved that problem by repeatedly running the engine in park at 3700 rpm for 60 seconds, several times, after they warmed up. That seems to loosen stucking lifters, and get them rotating again. A trick 5-90 taught me once, but he does not recall it, LOL.
Also, the 89 did the ticking after the engine was turned off, before and after replacing the head, where the head was serviced at a machine shop before I reinstalled. The head gasket was bad between #5 and #4 cylinders, which is the only reason the head was pulled, compression and bearings like a new engine, very low mileage 89.
I have over 120,000 combined new miles on these two jeeps with the engine off tick (8 years and 4 years), and it has caused no operating problems on either one.
