Rough idle turns into bigger problem! Help

[JoshAnthony]

Bought a 02 jeep liberty limited edition 3.7 with 106 000 miles on it. 112 000 blew the motor by leaving the coolant cap off one morning after filling it with coolant because the radiator had a small crack in it. Well that ended up blowing a head gasket i belive at 4 and 6 cylinders because the coil packs broke off when puling the motor.
$3000 and a couple days installing the rebuilt motor with new radiator, plugs, couple coil packs and fluids. Everything been fine since. Had the motor rebuilt back in Feb 2013.

Car now has 157 000 miles

Couple weeks ago noticed my coolant reservoir was leaking from the top right on top of 4 and 6 spark plug. One afternoon leaving work had a misfire when going home. So picked up a coil pack because after seeing the rust from the water on top if that coil pack i figured thats what it was. So drove to parts store packed up new coolant reservoir, coil pack and oem spark plug. Replaced 6 first because thought that was the one that went out. Well it was number 4. After that car ran fine since. Well week ago i started experiencing rough idle at stop lights then a little bit of hesitation when starting to go but eventually went away after getting to the speed of 10 mph so just brushed it off. I noticed it starting to get worse after driving it a couple days so it started worrying me. Went on forums to see what i could figure out. So after a little research at work i drove home. Went to go pass a car and when it started gaining speed it loses all power but does not shut off. Engine light starts blinking and engine is misfiring. I get it home and started pulling coil packs. Was gonna switch one with another to see if it would pull a code. Well after checking 6 spark plug i notice it has oil on the threads. All the others do not they all looked clean. well after checking everything. Start the car and suddenly just dies. Start it again, this time needing a little gas to get it started i hear a tapping noise from the motor. sounds like a piston rod . Any suggestions? Calling the company who rebuilt my motor tomorrow to see what kind of warranty i have. Let me know if you need any info.

 

[starrider06]

My '02 just started missing last night. was too dark to mess with, so I looked it over today. It's missing on cyls 1, 2, 4, and sometimes 3. Has a knocking noise that just started today after running it for about 10 minutes. Motor has 122k miles on it. Plugs and coils are about a year old. Got good spark and injector pulse. Sounds like the same issue you got. Have you got yours figured out? I realize this is an old post but it sounds just like mine.

 

[LibertyTC]

Nice Bump! Geez how did we "miss" a new member's post back from June?
Josh Anthony's problem by the tapping sound= probably a rocker fell off and hopefully got the engine repaired under warranty. Engine light blinking means pull over & turn it off!
Ok so..Starrider, I would remove the valve covers and have a peak in there. It could be that a rocker/s may have come off and can be placed back on.
I assume this is a top end noise and not the lower, what are the codes?
I will see if I can find the video in an edit.
Same principal for 3.7 and this is good to know if it happens in the middle of no where.
Link: https://www.youtube.com/watch?v=st1AoYfTPlY
If it truly is multiple coils misfiring, it could be a bad ASD relay too.

 

[starrider06]

Just like the Ford 5.4l! Is it possible for a bunch of them to come off at the same time? This motor didn't have the best care from the previous owner. Have changed the oil 6 times in the last 2000 miles and finding mass quantities of carbon in the oil filter and in the drain pan, I mean , LOTS. Didn't give any warning at all, just got back from a 120 mile trip, went to pick up the wife at work, and it was missing when it started up. Didn't want to stay running without a little throttle. Got home and it was running on 5 & 6. Pulled the coil wires off all the other coils, made no difference. only was hitting on 2 cylinders! Was checking for an electrical issue, thinking it had to be a wiring problem, then it started with a light tick which turned into a more solid-sounding knock pretty quick so I shut it off. Will pull the covers when the weather allows, will repost with what I find. I probably set a few codes when checking things out. Thanks for the info!

 

[LibertyTC]

Ya not good.
Generally what can causes the rocker to pop very well could be a build up of gunk in or around the lifter/rocker.
Pull the codes post em back. Get those covers off. Take a few pics in there, post em please.

 

[LibertyTC]

Conditions of plugs?Pull the spark plugs too and post pics identified by each cylinder#.

 

[uss2defiant]

what's the CEL codes?

 

[starrider06]

I pulled the valve covers and the #2 intake follower was out of place. The cam timing for both heads is okay. Still don't know why it was missing on all those other cylinders, might do a compression test before I pull it. I didn't pull the codes because most of them I probably set while diagnosing all the missing cylinders. While turning the motor over by hand to line up the timing marks, I noticed that there is a point at which it didn't want to turn any more but I am able to turn it past that spot with more effort, so I think it's probably done for. I put the "wandering" follower back in position and put the covers back on and started it. It ran slightly better, but knocks. Oil is slightly dirty, has about 1400 miles on it, doesn't smell scorched like it sometimes does on a bad motor. Sometime I'm gonna pull it and take it apart, probably next spring, when it warms up. This motor is REALLY dirty inside, carbon and sludge everywhere. It would take a lot of effort to clean it all out of the passages, etc. Just love those people who don't take care of their stuff, don't you? I'll probably just find another motor to put in it. Or do a v-8 swap. Dunno yet...

 

[LibertyTC]

Once the covers were off, I assume it was YUK? Any pics?
I assume you removed all the spark plugs before turning it, what did plugs look like? pics?
If it still knocking not good...
You can clear the codes by removing the battery cables for a few minutes, if you don't have a scanner to do it.
Would still be nice to have what codes are currently set.
Yes to compression test !!

 

[TwoBobsKJ]

...I'll probably just find another motor to put in it. Or do a v-8 swap. Dunno yet...

A V-8 swap is a JOB! And not too many have had a good experience once they got the V-8 installed.

If you end up putting in another 3.7 here's a link to the overview i posted about putting a newer 3.7 in my '03.

How-To: Engine Swap Overview


Bob

 

[starrider06]

Pulled the right head. The intake valve seat came out. Head is definitely done, but the piston doesn't look bad at all. A few grooves in it, and a couple divots. No embedded seat fragments. Am tempted to just replace the head and put it back together. After it started knocking, it ran for maybe 5 seconds before I shut it off and it wasn't running any faster than 1200 rpm at the time. Wasn't even driving it, was just looking it over in the back yard. Anyone else seen this happen?

 

[starrider06]

I am wondering if the cam follower coming out was a precursor or "warning" to the seat falling out?

 

[ltd02]

I am wondering if the cam follower coming out was a precursor or "warning" to the seat falling out?

I'd agree, probably related in your case. Then the seat just fully let go. I have dropped an occasional rocker but since putting in a new lash adjuster, all has been fine. Did he headgaskets a while back and the heads looked prett good in my case. arty52:

 

[rbtconsultants]

Be careful if any of the "dings" in the piston crown extend out to the edge of the piston. If that is the case you likely have pinched/cracked/broken the ring grooves on the piston. This was the bad one from the top and then what it looked like when I pulled it.

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This one was a cylinder where the seat did not drop but pieces got into it from going up into the intake manifold and down into this one. This one there was no evidence from looking at it, but the ring was pinched and bound so I had to replace this piston also.

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[starrider06]

Yep, the #6 piston had damage from pieces going through the intake too. Compression low in all 3 on the right bank, the motor was full of gunk inside, the front cover seals had been seeping coolant into the oil for what appeared to be for some time judging by the washing by the coolant passages. Going with a reman: don't have time to overhaul it this winter and am planning on keeping it until the wheels fall off anyway. All the used motors I find around here are expensive even with 180k miles in them- for about $500 more I get a motor with a 3 year/100k warranty and get it delivered. Nobody will warranty a used one if I pull the bottom end apart to replace the sensor ring on the crankshaft.

 

[Swisher]

This one was a cylinder where the seat did not drop but pieces got into it from going up into the intake manifold and down into this one.

I had this issue with the Liberty I bought. It dropped its #1 valve seat; ate it, then shared it with the other cylinders on the opposite side causing more damage to #4 than it originally caused to #1. In addition to the cylinder damage, both of my heads were destroyed. It completely wrecked the engine.

I was told by a guy with 40 years experience machining heads that it's a common issue with modern engines. The aluminium heads expand and contract from over heating causing the hardened steel seat to work loose from its boss. Modern engines also have a super powerful vortex within their intake manifolds which can easily displace the debris and distribute it to every cylinder. He said once an engine drops a seat --it's pretty much done.

 

[rbtconsultants]

Not necessarily done. If the bottom end is in good shape you don't need to scrap it. I put rebuilt heads on mine, with all valve seats replaced. I just replaced those two pistons, new timing chain set, some other misc. Under $1300 I have an engine I expect to run for another 130k. been back on the road a couple weeks now. If you have the tools and time and your bottom end is in good shape it's worth doing.

Bob