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Mom's KJ just dipped out all of a sudden


Knucklehead97
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My mom's had an 06 KJ 3.7l for quite some time now, never really had issues for the 7 years she's owned it. Just a water pump, AC compressor, little odds and ends. No big issues. She's changed the oil like clockwork and kept up with all other maintenance. It's just recently gotten to 250k on the clock and yesterday the engine decided to go. She was driving it like normal no issues or anything, stopped at a store and ran in real fast and when she came in it was idling rough and low. Had a mechanic pick it up and he said it looks like we hadn't had a tune up in ages and that we needed 2 valves and he would have to strip the top of the engine to do it. A 2k job. We just had a tune up done in February and it's only been driven 15k since then. I know it had been losing oil without leaking. Do you think it was burning oil and then the Pistons decided to lose a seal? This is new to me.

 

If this is considered tech instead, please move it. Wasn't sure about KJ tech.

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As soon as you pay for the valve job..........you'll lose the cam bearings or the bottom end.......or............?

 

Be grateful she got 250K out of it, it lived it's life.

 

Time for a new engine. 

 

This is the question I raised just yesterday, for those who read, what will you do?

 

 

Buy a rebuilt for $2K and pay the mechanic $1K to swap. 

 

 

Why don't you get two rebuilt heads and you do the job over a weekend? But I wouldn't do that either, the rest of the engine is worn out, too many miles. 

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Just looked up the value of 06 Liberty. My mother has the 02, it's their junk car now, they have a new Cherokee. 

 

$4000 to $6000 retail on a really really good day. 

 

Reality- $4500 as a average. 

 

If you paid for a rebuilt engine, or paid to have that one rebuilt, start to finish, shop prices, all said, my guess is $4200 on the low end, $4800 on the high end. 

 

New engine exceeds value. This is the question that will face 80% of car owners from now on. 

 

Just a straight rebuild, no extras, no goodies, just you doing the work, machining costs included, you might get by for $1400.........only then is it worth it. 

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Yeah, it's a hard choice to make.  I'd hate to blow a huge wad of cash on repairs to an old 3.7.  :( 

 

Is it running rough because the spark plugs are dirty?  My sister has that oil-leak issue in one of her GMC's cylinders and her plan is to simply replace the $2 spark plug on a regular basis.  It's not a horrible plan.  :dunno:

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Did you pull any codes, or are you just going on what the shop told you?

 

I'd suspect the coil packs, if nothing else points to anything definitely internal.  I've had 2 of them go on mine so far (only 125K miles).  #6 because I had a leak from the hose on the expansion tank directly above it...whoops....but I also had #1 burn a spark through the base of the coil shorting directly to the head.  That KJ was basically undriveable with the #1 coil not working.  It felt like the whole thing was ready to garage sale itself across the interstate, especially if I got any more than 1/4 of the way into the pedal.

 

I carry a couple spare coils and a 10mm socket with me now, LOL.

 

 

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She ended up going and buying a 2011 Corolla while I was at work... I couldn't look at it myself due to working 16 hour days right now. Didn't trade the Jeep in but she's planning to sell it. I'm thinking of looking at it before we sell it and testing the coils and stuff. I wanted to look at it before she bought something, but she knows I'm busy and she has no way to get to work. I knew the retail value was low on it so rebuilding the engine or replacing with new was out of the question. The mechanic said that he did a pressure test and 2 cylinders were dead. I know we're lucky for the 250k out of it. It was a GREAT Jeep for the 7 years we've had it.

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At this point, I'd be inclined to follow the shop's diagnosis and confirm the dead slugs.  Did they say which ones they were, and are they adjacent?  3.7's like to drop valve seats, and/or have the rocker arms fall off:doh:.   If it dropped seats, you'd need a new head/heads, depending.  If a rocker fell off, there's a chance you can reinstall it/them.  If the 0 compression is on adjacent holes, I'd be thinking headgasket (but wouldn't rule out the valve/keeper issues, either).  Can you do a compression test?  Code scan "should" tell you which ones are affected if you don' t know for certain.

 

edit to add:  at 250K, that old 3.7 really doesn't owe you anything, LOL.  I'm going to try to get mine to about 200K and sell/trade it if it makes it.

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5 hours ago, mjeff87 said:

At this point, I'd be inclined to follow the shop's diagnosis and confirm the dead slugs.  Did they say which ones they were, and are they adjacent?  3.7's like to drop valve seats, and/or have the rocker arms fall off:doh:.   If it dropped seats, you'd need a new head/heads, depending.  If a rocker fell off, there's a chance you can reinstall it/them.  If the 0 compression is on adjacent holes, I'd be thinking headgasket (but wouldn't rule out the valve/keeper issues, either).  Can you do a compression test?  Code scan "should" tell you which ones are affected if you don' t know for certain.

 

edit to add:  at 250K, that old 3.7 really doesn't owe you anything, LOL.  I'm going to try to get mine to about 200K and sell/trade it if it makes it.

I can't do a compression test but I can pull coil wired while it's running and see which don't change the idle. Was going to work on it Thursday but my daily driver window decided to all of a sudden fall and shatter going down the interstate in a monsoon today. Not sure why this all happened the same week. I have a computer to scan with so checking codes will be my first test. May call up the shop owner and talk to him to hear his whole diagnosis. My mother isn't very car-savvy

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Cranked it up, ran perfectly fine for 5 minutes. Can't be the valvws. After 5 minutes it started running real rough and threw P0300, 0302, 2305, 2308, 2311, and 2317. That's multiple misfires, cylinder 2 misfire, and ignition coil B, C,D, and F. It'll randomly start running good again and then get bad again. I have 10 days to get this fixed before my mom can't take back the Corolla. Any guidance?

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38 minutes ago, Pete M said:

what do the plugs look like?  wet?  oily?

Neither. Dry for the 3 on the right. They're old though. Definitely needs plugs, so I'll pick those up tomorrow. Couldn't pull the left 3 today due to my fiance requesting a late lunch date. How can I test the coil packs? It looks like the front 3 or 4 cylinders are not firing.

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http://www.denlorstools.com/autoblog/2010/04/misfire-3-7-4-7-dodge-or-jeep-falling-rocker-arm-problem/

 

Valves sticking. 

 

This is likely the problem. Cause for the no compression that  you state the mech found. 

 

Quote

The general consensus among several master techs that I discussed this problem with is “the main cause of  a fallen rocker arm in a 3.7 or 4.7 is from excessive carbon build up.” Carbon build up on the valve stem can cause the valves to stick momentarily. If the valve sticks for a fraction of a second too long, the rocker arm can be allowed enough clearance to fall. Other causes can be faulty valve seats or worn or defective valve springs.

 

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1 minute ago, Knucklehead97 said:

I'll probably pull the valve cover tomorrow to check the rocker arms if the new plugs don't fix it. Why would the engine run fine for 5 minutes today if it dropped a rocker arm?

The valve got unstuck, you started it up, warmed up, got stuck again. 

 

This makes more sense than 2 or more coil packs going bad at once. 

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Changed the plugs and it didn't change anything. Upon pulling the other 3 plugs I hadn't messed with, I found 2 and 4 to be covered in gas. Pretty sure at least one rocker arm dropped. Sadly that's the side with the valve cover that requires a lot of things to be removed before you can actually pull the cover.

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52 minutes ago, Jeep Driver said:

Is the KJ in otherwise good shape? 

 

If so, ask her if you can buy it from her for few hundred dollars, take a year to build a new engine at your leisure. A year from now you'll have a decent driver. 

I thought about it but I just bought an engagement ring, built the suspension in my Jeep, about to put a down payment on a house, and already have 2 immobile cars in my mom's yard. We're probably just going to Craigslist it sadly. Transmission, transfercase, and everything else is perfect on it. I just bought her brand new tires for it as well which is really upsetting to me.

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