I just purchased a 91 XJ 4.0L with 200k miles on it. There is a "tick"-"chug" noise mainly heard at the top, but also at the bottom too. I pulled the valve cover and found I have a collapsed lifter (back one of number 5 cylinder). With a remote starter I held on to the pushrod and the cam pushes the valve up and down so I know the cam's not flat. When I'm driving on the freeway it really sounds like a quiet exhaust chug. Would a stuck/ collapsed lifter sound similar to an exhaust leak? Or is it more likely I have both?

 

x2, i have the same problem

 

You need to fix the lifter problem first then check for leaks.
I just changed the lifters in my '94 for a lifter that came apart. I also had to put on a new muffler cause it had a hole in it from the backfire that took out the lifter.

 

Thanks, I pulled the oil pan to clean out the sludge and in the process changed the flange gasket at the exhaust manifold. Now there's only the ticking at idle but it goes away when the pressure builds up.