Need some opinions on engine rebuild/replace

Went to start the old girl this morning (88 4.0l renix auto 4x4 just under 170,000 miles) and she wouldn`t start. Played with/shook all the electrical connections and checked the oil level while I was at it . The oil level was well below add , last week it was full, my brother ran it yesterday and didn`t have any problems. Coolant color has changed to gray/blackish. More oil than usual is sprayed on the bottom of the engine/body. I finally got her started and the engine has a bad knocking ,plus is running roughly. My mech took a listen and said it sounds like cracked piston/bad rod. He also said to plan on new bearings and possible crankshaft based on how she sounded (before now) on start up. Rebuild current engine, jasper engine , or call it quites. Rest of her seems to be in good shape, very minor body rust, 4wd can be cranky( sometimes hard to get in). All suggestions will be appreciated. My mech is semi retired and won`t take on a rebuild anymore , will need to find someone else (sucks! big time).

Jasper engine is your best bet, they make good 4.0s

ravi

I know you already mentioned checking the electrical connections, but just confirming you tried hitting the crankshaft sensor. Whenever mine won't start, that's the problem.

kj139 said:

I know you already mentioned checking the electrical connections, but just confirming you tried hitting the crankshaft sensor. Whenever mine won't start, that's the problem.

Click to expand...

I did get it started but the engines a mess.

Copy, I missed that. One thing you might check before pulling the engine...Check to make sure the crankshaft is tight. I had similar problems (knocking with a mechanic diagnosing it as a bad piston/rod). When I was disconnecting the engine from the transmission, I turned a bolt up front to be able to get to the bolts to disconnect the transmission and it was very loose. It might not be your problem, but it only takes 2-minutes to check. I'll keep my fingers crossed for ya.

Good luck!

Thanks but there also appears to oil in the coolant bottle.

Sounds like you should think about lending your jeep to your brother!