So, I installed an ATK reman 4.0 into my jeep last month and it has started ticking on cold start-up. The ticking lasts until the engine has warmed, but will not go away until I rev the engine a bit when warm. If it don't rev the engine the ticking remains. Once the engine is warm, it sounds perfectly normal.

The engine will then not tick for the rest of the day, but will tick again upon start-up the next morning.

The tick does not get louder with revving the engine, but does increase with speed. Although, the tick is fairly loud to begin with....

Any ideas?

Sounds like a lazy lifter. You try some Marvel Mystery Oil yet? Oil Pressure is good?

Oil pressure is good. I have not tried any additives yet...honestly, I don't think I should have to on a new motor.

Exhaust leak?

That's another possibility. I'll be checking the bolts on the intake/exhaust manifolds in the morning...since the jeep is already hot.

Check the exhaust manifold itself as well - very failure prone on the 4.0...

i would also lean towards a valve or lifter. i would think a exhaust leak would be there all the time and never really quiet all the way down.

i would also lean towards a valve or lifter. i would think a exhaust leak would be there all the time and never really quiet all the way down.

On my 95 ford I have an exhaust leak when its cold... goes away after 5 minutes, cracked exhaust manifold. also on my 96 cherokee I have the same issue... when things heat up they expand and seal the leak...not saying this is his issue, but its possible.

piston slap,its very common on the 4.0's

On my 95 ford I have an exhaust leak when its cold... goes away after 5 minutes, cracked exhaust manifold. also on my 96 cherokee I have the same issue... when things heat up they expand and seal the leak...not saying this is his issue, but its possible.

yes could be. anything is possible i hate leaks and noises and shit that you can never tell exactly where they come from. it sounds like one thing but sounds like its coming from 3 different places when you start searching for it.

Oil pressure is good. I have not tried any additives yet...honestly, I don't think I should have to on a new motor.

You don't have a new motor. You have a mass produced reman'd motor. Sometimes stuff sticks. Throw a quart of marvel mystery oil in it and see if it goes away. Start with the little shit first before you start beating down their doors and going at it over warranties, which you may have to do anyways if you don't find the problem.