Toecutter

Ok, 2 weeks ago, out of nowhere, it started running a little rough. My son was driving my Jeep on the highway when he observed it vibrated a little when he applied the accelerator. By the time he got home it threw a code, P0305, misfire on cylinder 5. I drove it a little the next day and seemed fine but started to run rough the warmer it got. Over a couple of days it got progressively worse. Long story short, after ruling out spark plugs (replaced), coil (tested) and vacuum leaks (repaired), I finally tested compression. All 150lbs except #5 was only 30lbs! After pulling the head and inspecting the valves which all looks great, I pulled the lifters on #5. Intake lifter is shot. My question is, can I get away with just replacing the lifters? Please say yes. I just sunk $2200 in a transmission rebuild so anything else that needs doing I'm doing myself.

Toecutter

FYI it's a 2002 Grand Cherokee with the 4.0. I can't tell if that's in my profile from my phone 😄

dave1123

NO, I'm sorry to say that cam is toast. Once the lifters start to dish, they round the cam lobes and eventually wear holes in the bottom of the lifters. If you put new lifters on rounded cam lobes, not only will they wear out fast but they will start to wear the lobes flat again reducing the lift.

If you're looking to dump this jeep on some unsuspecting buyer, you can stick new lifters in it, but we don't do that, do we?

Your sig says 98 Grand.

Toecutter

In my heart I knew that would be the answer. On a scale of 1 to 10, how tough is it to replace the cam? 1 being air filter change, 10 being complete engine overhaul. Looks like the radiator, fan & water pump have to come out along with the timing chain & cover (obviously) and the cam just pulls out of the front. I'm doing this in my driveway so I'm not happy about the idea of disconnecting the AC lines. My only resource has been my Hayne's manual, some YouTube videos & this forum but so far, so good. Any tips or suggestions would be appreciated. I'll post a couple more pics in a bit.
P.S. I gave my son my old 98 GC. Profile updated!

Toecutter

After removing coil pack, fuel injection, intake & exhaust manifolds.

Toecutter

After removing valve cover, rocker arms & push rods.




The fulcrums on #5 did show some wear. Also, the pushrod on #1 exhaust valve showed a slight bend when I rolled it on a piece of glass.




Head removed! Everything in there looked really clean. No carbon on piston crowns or around valves. Nothing snotty.




I'd prefer to use my work bench but it's still covered in boxes from moving in last November. At least the weather here in Texas couldn't be better right now.




I was hoping that the problem was with the head but everything looks good. My #2 son's Beetle is the next project.

dave1123

Take a look at the head casting surface around the valves between #3 and #4 cylinders and see if it says "TUPY." If it does, that means you have the recast 0331 head that's not supposed to crack. If it doesn't, you still have the old 0331 head. The new casting was installed sometime in the 2002 production run. It's the same head, just recast in Brazil with nickle added to the pour.

As far as removing the cam, you may have to remove the grill as well. That "stick" is quite long and IDK if you have enough clearance to pull it out with the grill and front fascia on it. I suppose you can release the engine mounts and jack up the engine to clear the fascia if need be. Fascia = bumper. Don't forget to pull the oil pump drive gear. Turn the engine over to TDC #1 and note the position of the cam sensor drive slot so you can put it back "in time" on re-assembly. You can use the chain sprocket as a handle when installing the cam to get it thru the bearings. I always use a heavy lube like STP or cam lube when installing a new cam for that initial break-in lube before oil pressure comes up.

That's another thing you might want to do. Take out the ASD relay and crank it over a few turns to get oil flowing before firing it up.

OH! Almost forgot. I'd advise a new set of head bolts.

About the Beetle, the one thing that made my 68 Beetle run great and get incredible fuel mileage was an equal length 4 into 1 exhaust header with a glass-pack muffler from EMPI or something similar. It made the Beetle sound like a Triumph TR3! What killed the Beetle was a catalytic converter made them run hot!

Bustedback

You have the engine torn down that much already, it may be easier to pull the block out to do the cam instead of removing the whole front end.

dave1123

Naturally Bustedback has done this before! One thing, if you pull the engine, unbolt and leave the torque converter in the transmission. You can damage it trying to thread it back onto the transmission when it's attached to the engine. Also, buy a new Mopar CPS to install when you put it back in.

abodyjoe

yup cam needs to be done.. in reality the entire engine should be rebuilt or at least pulled apart and cleaned at this point.. all that metal went throughout the engine. just throwing a new cam and lifters in it may work but i've seen too many times that metal from th eold lifter/cam also wiped out the bearings in th elower end..

Bustedback

I haven't done a cam swap on a Jeep yet, but the cam is damn near three feet long, no way of sliding it out without stripping the front end. Then it still might not clear the front unitbody crap.

Toecutter

So far this is my fix.




2006 Wrangler Unlimited. Been having too much fun driving it to keep at the GC. More than likely I will just install the new lifters this weekend and just drive it till it pops. I agree replacing the cam and or rebuild would be the way to go but I'm just not sinking any more cash into her. If it does self destruct I might buy a rebuilt short block but that's it. Too many projects stacking up! I'll let y'all know. Thanks for the input!

abodyjoe

Ummmm. If the lifter is bad so is the cam. Don't bother wasting the time or money putting new lifters on a bad cam.

97grand4.0

Im with you. lifters and down the road.

peep

I can't understand the decision to just drop in new lifters. There is no majic going to occur that will fix the cam. You need to finish the cam job.
You have it stripped that far.
You've invested a lot of work already. Your almost done.
Remove the front accessories and cover, undo the engine mounts, leave the trany intack, jack the engine up to aim the cam thru the grill, with rad and grill removed, pull the cam. Put in the new parts and enjoy the rest of the GC life span. Looks like the balance of the engine is still intact. Do two complete oil changes with fresh filters to flush any debris. Abodyjoe has a significant point in the chips from the disintegrated lifter and cam lobe being somewhere in the internals.
Why waste on new lifters and a no good reassemble?
You will self destruct in a few miles and have a no engine vehicle that's junk.
If you deal the vehicle, it will self destruct on the next owner.
Better to sell it as basket case and let the next owner finish the repair.
You posted for opinions.
My 2 cents.