Destroyed piston, what to do?

[spoons72]

Bought a 2000 TJ - 2.5 l knowing it had a bad knock and was blowing smoke.  Lots of coolant in the oil pan.  Just got the head off and piston closest to firewall is sitting right at the top, touch of an angle, missing a couple of pieces and has left some good gouges in the cylinder wall.  Best part was all of the oil that poured out of the intake when I took it off.

I was told not to bother with a bore and rebuild on a 4 banger.  I do not plan to build this into a trail rig.  Hoping to bring back to life, sell and then find a 4.0.

I am no mechanic, Youtube got me through most of this removal and my Haynes manual.

I got this jeep for a screaming deal as the owner didn't want to deal with the issue.

So not sure if I should rebuild or simply find another motor.  Any advice would be appreciated.  Thanks.

[tubby]

I've helped rebuild a few 4 bangers out of Jeeps for a friend who used to own an automotive machine shop. I've found that people who bring engines to be rebuilt are shocked at the bill. They don't realize the amount of work it takes to properly rebuild an engine.
Are you planning to disassemble the block and have the head rebuilt, and the block bored-out( that's assuming it's salvageable ), and the final assembly done by yourself? That would be the cheapest option. Dropping it off and having them do all the machining AND assembly quickly adds up.

Save yourself some grief and find a low km 4-banger TJ that's been rear-ended or something. It's not a rare engine to find used on Kijiji .

[vantagetes]

Buy a 4.0L for it. The only somewhat tricky part is moving the motor mounts (need to do some welding). If you had a 2.5L your axles are already geared pretty low do with a 4.0L you could run a mild lift and 33" tires and be perfectly happy.

Alternatively you could probably find a used 2.5L for cheap.

[spoons72]

thanks tubby.  I thought I might get it machined, but the gouges in the cylinder wall (2 that I can see so far) are pretty deep.

I called one place 2 weeks ago (before I started pulling it apart) that I found on some thread here.  Nice guy, said $1800 if I pulled the motor and brought it in, pan to valve cover.  He would return it painted and ready to go (I am guessing if the block was good).  For what I paid I would still come out way ahead at that. But I'm cheap and trying to learn.

Are wreckers the best option for a motor?

[tubby]

Are wreckers the best option for a motor?

Been there done that. Crap shoot.

I've had better luck with engines that were still in vehicles to see them run on their own power, and I can talk about the vehicle's history with the owner and do a compression check, listen for death rattles etc.

Vehicles in junkyards are there for a reason. It could be that their engines were toast? I don't want to be the guy who spends hours unbolting an engine only to find it was as shitty as the engine it was replacing. Crap shoot. My favorite ? " it ran fine when I pulled it"

Find a low km 2.5 in a TJ that has minimal body damage or from a guy looking to go to a 4.0

[JENSSEN]

My rule Of thumb is never pull an engine out of a car without write off damage, look for a minty car with big damage(that never got close to the motor) and pull that one if you want to do a J/Y motor

[cLAY]

I've bought a couple of engines through here and have had good luck.   http://car-part.com/

Any reputable wrecker tries to run the engine when it comes in and check the compression and oil psi. Both my engines had the compression results written on the exhaust manifold and both had a 30 day warranty.

Never buy a motor that has been in a HARD head on collision that show signs of an impact to the crank. A blow to the front of the crank will often damage the main bearings. Engine will run fine initially but then the bearings will let go in a month.

Personally I find buying a used motor the way to go. Should be able to find a motor for under $1000 easy. Sometimes I buy a whole vehicle and part it out and in the end the motor ends up being free.

If you really want to put a new on in try talking to your favorite Dodge dealer. Chrysler was blowing out older  mopar  rebuilt motors. I got my 5.9 for the ZJ for $1600. They wanted $1800 but I chewed them down a bit.

[spoons72]

Thanks for the advice from everyone.  Gonna try some wreckers today (looking as per the advice).

Might post some wanted ads as well.

Thanks!!!

[cLAY]

Don't be afraid to have an engine shipped in from out of town. Both of mine came from out of town. The last one was from Barhead and I believe it was $80 to have it shipped to a depot in Calgary where I picked it up.

[spoons72]

Thought I might as well post a pic so I added it to my initial post...

[morerpmfred]

Looks like thete is no carbin build up on the top of either piston. I suspect that moter was just rebuild or overhauled. Possable assemled wirh new rings and bearings but no oversize piston? The sloppyness in the bore could crack the piston on cold startup? Was there a rattle on startup?

[morerpmfred]

Is there a carbin build up ridge that you can feel with your fingers rsticks out?

[morerpmfred]

Meant to post is there carbin buildup ridge at top of cylinder bore? That you can feel with your finger that sticks out?

[spoons72]

Ill check tonight.  I bought the jeep with the brutal banging already there.  I do not know if there was any work done.  She told me she drove it for a couple of days with a lot of white smoke which turned to banging which turned into her pulling it over and having it towed..  Btw, i tapped on the piston and it went down (obviously with nothing connected to it), got it almost to the bottom.

[cLAY]

Headgasket went, filled cylinder with coolant which steam cleaned piston(thus no carbon). Eventually thinned oil, siezed bearing, broke rod and piston.