Stock 4.0 build problem
Posted: April 4th, 2014, 10:55 pm
This isn't stroker related but i do have a stroker in my other jeep. i just figure the expertise on this site might know. I bought a '97 Grand Cherokee for $500 a few years back. Everything was good except a junk 4.0. he must have never changed the oil because it had a grenaded piston and the oil looked like tar. Recently I finally got enough money to rebuild the engine. i bought a rebuild kit online and sent the block and head to a machine shop for some basic machine work. I only had 120,000 on it so i was hoping to just have it hot tanked, wrist pins and cam bearings installed. They convinced me to go .030 over. I got a good deal under the table. All i did with the head was lap the valves. I had to send the pistons and rings back for the .030 ones. Anyway i rebuilt it and in less than 50 miles it was making a noise like a collapsed lifter. It wasn't. i pulled the head and found all pistons with rub marks on the cylinder walls but #5 was the one making the noise. It is so bad that I will be lucky to bore it again to salvage it. I researched the P/N's for the pistons and rings and it turns out they sent the 93-95 ones. i did more research to find they are slightly different yet they are the same bore. Is that my problem or just coincidence? i am not an engine builder and could have screwed something up without knowing. Does the company that gave me the wrong parts owe me a long block or am i screwed?