FreshFlesh

Hey everybody.
I just bough my first jeep 2 weeks ago. In these 2 short weeks one of the cylinders gave out, I paid $650 to get that repaired. It worked fine, but my wife and I took a trip into the mountains (road only) and the engine was making all kinds of sounds (Ticking and like there is a hole in the header). The mechanic that worked on it said that everything looked ok, but now im scared that it will be my black hole (money go in and disappear). Should I keep repairing the engine or save up and get a new remanufactured one (company in Jersey sells them for $1900 and gives a 3year unlimited warranty)?
THe current engine has only 97k on it and complete replacement will cost me about $2700.

Radi

97K isn't even broken in for a 4.0, unless the prev. owner abused or failed to maintain it.
I'd do an assessment of it's current condition- check compression (leakdown test is better), oil pressure, presence of goop under the rocker cover, in the oil pan etc. If it looks like it's still basically solid, repairing manifold leaks and such would be my choice. OTOH if the engine has been so poorly maintained that it's ready for the crusher, cut the losses and rebuild/replace.
Losing a cylinder this early isn't a good sign....what needed to be repaired?

FreshFlesh

When I got it, there was a leak around head gasket, small, nothing major. When the cylinder was repaired ( dont know exactly what needed the repair, wife couldnt explain nor am i a mechanic) the head gasket was replaced. Engine otherwise is pretty clean, no visible leaks. Oil pressure is steady, no drops. No goop under.
I dont know the previous owner, it might have been abused, or neglected, there are a few things around the car that dont work.
The engine is a major one. It sounds pretty bad when on. Ticking is pretty loud. Now I also noticed that it shakes mildly when stopped at the light.

cmartin2112

Check your ignition componets that might be why it is trying to run rough.

Since the oil pressure is pretty steady that is a good sign (when my motor took a dump the oil pressure dropped to almost nothing). You said you popped the valve cover off did you check the rocker arms and push rods for any play? If not that might be the reason for the ticking. How did the oil look?

Firestorm500

Get an exact diagnosis on the ticking. Could be cracked exhaust manifold, exhaust leak, lifters, injectors, etc.

If it is the exhaust manifold, too bad that wasn't taken care of with the head gasket.

What year model is your Jeep?

FreshFlesh

Took it to another mechanic, he told me that he wont know exactly until he takes off valve cover ($200 just for that)... but he did say that its either rocker arm or a push rod.
How hard is it to do myself? I'm not a mechanic but comfortable with a wrench (I do service myself on all of my bikes).
PS: The jeep is 01.

Fsher21

The valve cover is very easy to get off, just have a few wobble extensions to get to the back bolt by the firewall. the cables going to the tb pop off easy and the bracket comes up with 3 bolts removed and can be positioned with cables attached, back behind the coolant bottle area. The pcv hoses or whatever that is called can just slide off the 90 degree plastic piece. If the cover hasn't been off in a while I suggest buying a new rubber gasket to be safe, plus it can come off many times after that and work fine. Avoid knocking crud into the oil after it is off and make sure everything is clean when going back on.

I am not familiar with checking the rocker arms or rods besides just a visual check.

cmartin2112

Get a wrench on the top of your rocker and twist your push rod with your fingers, tightin the bolt ontop of the rocker until the push rod sits snug.

I dont know if these enignes have this feature but you might need to grab a feeler gauge and check the distance between the rocker arm and the valve spring.

Radi

The lash is hydraulically adjusted by the lifter. There should be no clearance between rocker arm and valve stem. If there is, and the rocker arm is not loose- the lifter is shot.

cmartin2112

Ok that makes since. But he should check the play in between the push rod and the rocker right?

Radi

Sure. If there is a gap there, something's wrong. Bad lifter, loose rocker arm, etc.

The 4.0 is not a quiet motor, particularly when they have a few miles on them.
Some are reminiscent of a Cummins diesel. Others a singer sewing machine.
Klack klack klack out of a lifter is probably more common than not.
It's a bit scary if you've never owned one before.

Have you checked for exhaust manifold leaks? They are not uncommon and can make quite a racket. Plug the tailpipe with a wet rag and go look and listen for escaping exhaust.

If you want to be certain, have a look under the valve cover for anything loose or broken.
Pull the oil pan, check for metal scrap like piston skirt chunks.
Pull the rod bearing caps and check bearing clearance with plastigauge.
Check the oil pressure with a trusted mechanical gauge, and check cylinder compression.
If no problems are found, you can be reasonably certain the noises you are hearing are not a serious motor problem.

cmartin2112

When I first bought my jeep it had horrible oil pressure and a pretty loud knock. I asked a buddy of mine who owned a wrangler and he told me that Jeeps just knock and there was really nothing you could do...

Now come to find out since I am doing a rebuild on my motor the camshaft had a little chip on one of the lobes and all my bearings and crank journals look like they were starved for oil... That was probably the reason for my knock.

But to help the poster out I would do what Radi says just try and check all your major things and if nothing is there then you are probably alright.

FreshFlesh

Thanks everybody. I will try to do all of it when i get a spare minute... I must say, Radi and cmartin, you've made me breathe easier. My wife was already giving me "that look" about wasting money.

Phat jeep

Really don't want to scare you I had a similar problem a few months ago. My Jeep had done 95k miles at the time and the ticking noise sounded like it came from the rear head area.
I am mechanically minded and have never paid a mechanic to fix or service my rides. I took it to the local "Jeep specialist" and he said I had a few sticking lifters. He sold me some lifter free up and said it would take up to 500mi to be quiet again.
200mi later my torque converter bolts let go and the front seal and bearing were destroyed
If you have an auto it is worth checking.
It is easy to check and only costs a few minutes.
Remove the inspection plate at the back of the engine (front of transmission) on the drivers side, rotate flex wheel with a flat head screwdriver ( or get someone to flick the starter) and check all 4 bolts. If any are loose remove them 1 at a time, clean, apply locktite and re-install and re-torque to specs. Check each hole in the flex plate because if it is out of round the problem will get worse.
Tightening 4 bolts or replacing a flex plate is way cheaper than replacing the whole trans.
I hope I'm not leading you astray and that you do find and fix the problem asap.

cmartin2112

No problem man! Anytime you need help just do some research or reach out and somebody here can help you out! Also let us know what the end result is.