Need to replace my 2002 KJ engine

[Kingj28]

My 2002 KJ engine just had the dreaded valve seat drop and killed my engine. I want to keep it since I have replaced many parts on it already and it rides super smooth with the new bilstein shocks and Moog springs. My question is what needs to be done to the reman engines to prevent these factory defects from cropping up again or is this just the way it is with these engines? Need to know before I sink 3k plus labor into this. I don't want to end up in the same boat a couple years down the line, I need a fairly reliable ride for my wife. Any input would be greatly appreciated.

 

[lfhoward]

Jasper remanufactured engines are supposed to correct design defects like this. I am not sure but maybe they pin the valve seats or something. Jasper offers a 3 year, 100k mile warranty on both parts and labor to back this up. The cost is more than a junkyard engine swap, but you get peace of mind knowing you’re covered.

 

[sota]

read the fine print on Jasper's warranty.

 

[lfhoward]

I think they require proof of regular oil changes and preventative maintenance. Is there something in there that is cause for concern?

I have a Jasper in my KK from 2014 and it is well out of warranty by now.

 

[sota]

last time I looked, warranty was void if engine not installed by a "professional" mechanic.
Personally I'd be hunting for a running parts jeep to yank an engine out of. Hell if the OP wasn't on the opposite side of the country, I'd make him that offer from the parts jeep I have here.

 

[lfhoward]

That’s true. They ship to shops, not individuals. If the OP has the capacity to do an engine install from a parts Jeep at home, that would save thousands. If looking for a running engine, look for a totaled Jeep in the junkyard. It “ran when parked.”

 

[Shankster]

My short block from these guys is still going strong after 8000 miles.

Dodge Ram Jeep Liberty Nitro 3.7 Engine Rebuilt Reman 12 Month Warranty - Cars and Engines 4 Less

GOOGLE US “FL ENGINES 4LESS” Upon purchase provide your EMAIL ADDRESS (CONTACT INFORMATION) “This is required before we ship your item” 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Dodge Ram Dakota Durango Jeep Liberty Nitro Commander Reman Engine V6...

flengines4less.com

 

[Roz]

My short block from these guys is still going strong after 8000 miles.

Dodge Ram Jeep Liberty Nitro 3.7 Engine Rebuilt Reman 12 Month Warranty - Cars and Engines 4 Less

GOOGLE US “FL ENGINES 4LESS” Upon purchase provide your EMAIL ADDRESS (CONTACT INFORMATION) “This is required before we ship your item” 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Dodge Ram Dakota Durango Jeep Liberty Nitro Commander Reman Engine V6...

flengines4less.com

Is there anyway for a shop to do something to the valve seats so the valve seats don’t drop

 

[sota]

yea. put in the newer/harder seats, which most shops do now by default anyways.
also, don't overheat the engine. EVER.

 

[Shankster]

Is there anyway for a shop to do something to the valve seats so the valve seats don’t drop

Apparently there is - in that link I provided above flengines4less says "Valves Seats are secured to ensure that this won’t be a problem in the future". When I had a cylinder head redone I asked the machinist to "pin" the valve seats since that's what I had read you want to do. However I've never been sure if that's the right terminology - when I got the head back I forgot to ask him what he'd done but it looked like he'd "peened" the valve seats" - i.e. there were several punch marks around the outer radius of each seat between the seat and the head. That might prevent them from rotating but don't see how it would help preventing them falling out?

I think what happens is that when the engine overheats, the aluminum in the head expands more than the sintered steel valve seats, thereby causing the seats to loosen. Maybe a valve seat with a thermal expansion coefficient closer to that of aluminum is the fix?

Anyhoo, hopefully someone else chimes in who's more knowledgeable about this - I'd sure be interested to know for sure what the proper fix is.

 

[u2slow]

I had a valve seat drop too. Happened on a cold startup, and didn't even get to run a minute. Didn't wreck anything major.

I was lucky to have a parts-KJ on hand with a blown head gasket. I took a head from it, had it surfaced, swapped it on. Here we are running fine some 12,000km later.

 

[Shankster]

I just did some googling and it does seem that when people say pinning they actually mean peening, which would be what I describe above with the punch. I had imagined a pin being driven through the seat into the head as some type of fastener but that doesn't seem to be a thing - I'm going with peening until someone tells me otherwise.

I found this video where the guy talks about (and demonstrates in the shop) "swageing" valve seats - hitting the aluminum with a round tool around the outside of the valve seat, causing a deformation of the aluminum above the seat and creating a lip over the top of the seat to help it stay in place. He also mentions how it causes the aluminum to compress around the seat thereby grabbing it tighter. He does this with existing seats and does it instead of replacing the seats. Sounds like installing new, better quality seats is another more pricey fix. He also mentions what sounds like "pinning", or did he say "peening"??? but says he doesn't like the look of that fix. Based on his detailed description of swageing, peening probably also causes the aluminum to grab the seat tighter, at least at the punched (peened) locations (I think my machinist did it 4 times per seat).

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So according to this guy, the 3 fixes are:

1) replacing valve seats with better quality ones (expensive but effective)
2) peening the seats like I describe in the previous post (cheap, ugly fix and probably a common practice in machine shops)
3) swageing the seats like the guy in the video does (cheap, less ugly fix but may not be a common practice in machine shops)

Are there any others?

Again, I'm no expert here and would welcome input from someone with more knowledge on the subject.

 

[lfhoward]

Peening makes so much more sense than pinning! Thanks for that explanation.

 

[u2slow]

I had my old head (that dropped the seat) rebuilt at a shop. They said they weld around the seat pocket to make it shrink.

 

[Celticlady]

That’s true. They ship to shops, not individuals. If the OP has the capacity to do an engine install from a parts Jeep at home, that would save thousands. If looking for a running engine, look for a totaled Jeep in the junkyard. It “ran when parked.”

Recently seeing a lot of 2002-2007 liberty's for sale on FB with dead transmissions. $1000. NW AR.

My trans went out at 170,000. Its the dreaded selinoid valve bank deep into the trans.

Not knowing what you have I suggest doing them both.

 

[u2slow]

Recently seeing a lot of 2002-2007 liberty's for sale on FB with dead transmissions. $1000. NW AR.

More like the last 10 years here. Dead trans or dead engine - flip a coin. That"s how I have a spare one for parts!

 

[sota]

Recently seeing a lot of 2002-2007 liberty's for sale on FB with dead transmissions. $1000. NW AR.

My trans went out at 170,000. Its the dreaded selinoid valve bank deep into the trans.

Not knowing what you have I suggest doing them both.

Unless there's a second solenoid pack I don't know about, the pack is pretty easy to get to. drop the pan, drop the filter, undo 4 (iirc?) bolts, and it drops out. unplug the connector obviously.

 

[Kingj28]

Recently seeing a lot of 2002-2007 liberty's for sale on FB with dead transmissions. $1000. NW AR.

My trans went out at 170,000. Its the dreaded selinoid valve bank deep into the trans.

Not knowing what you have I suggest doing them both.

What year do you have?

 

[Celticlady]

What year do you have?

06. But as I understand it the selinoid bank is common to all of the gas 3.7

My research showed it above the valve body. Depending on your ability, the exhaust may be needed to remove to get to it.

WHen it goes it puts the trans in limp mode. 2nd gear only. I had to go a hours drive at 45 to get home.

I would still keep your liberty. You got a lot of good $$ in other maintenance done. I would not put a salvage engine or trans in it. Get the low end rebuilt at your local transmission shop. You are most of the way there pulling the engine. Just drive it for the next 5-10 years.

You may want to insure it with Hagerty to cover actual value to you vs blue book

 

[Shankster]

I would not put a salvage engine or trans in it. Get the low end rebuilt at your local transmission shop. You are most of the way there pulling the engine. Just drive it for the next 5-10 years.

I agree with Celticlady 100% here. Salvage engines and transmissions are a crapshoot - I've put 3 salvage engines in other vehicles and 2 of them failed within a couple of years. I rebuilt the original engine in my Liberty and it failed within 3000 miles - turned out the machine shop I used did not grind the crankshaft straight. Go with an engine rebuilder that specializes in these engines (and understands the valve seat issues) which will give you the best odds of getting something that lasts. I also agree on the local transmission shop - I've had bad luck with buying rebuilt transmissions from outfits that churn them out - probably low paid, unhappy employees who don't care about quality of work. A reputable local shop working on a transmission you know is already fairly healthy sounds like the best way to go.

Also, invest in a complete new set of coolant hoses, new radiator, coolant reservoir cap, thermostat and water pump - I bet the most common reason for "new" engines failing within the first few years is due to an issue with the old cooling system that causes overheating.