I have a 1995 Z28 auto w/91k miles and blew the LT1 without even trying.

I was in process of merging into the highway rolling 15 mph and as the trans shifted to second, "boom" sound followed with lost power. Initially, it felt like a flat tire but when the smell of oil filled the air I turned the car off right away as I pulled to the shoulder of the road. I looked underneath and could see the timing chain hanging......not a good sign.

I had the Z28 towed and jacked it up for closer inspection. I could move the crank pulley up and down and knew the motor was a goner. After a complete engine removal; two piston rods broke off, crankshaft separated in half and a hole in the engine. The oil leak was caused by the crankshaft portion that broke off puncturing the oil pan. How could this have happened? I never even took this car past 100 miles per hour. Oil changed every 3 months.

I just dont get it, I have a 1989 L98 GTA that I beat on but never gave away. I thought LT1 were strong engines as proven in previous cop car line up. Could this have been a lemon? I have noticed that 6 months ago oil started leaking from the intake (infamous intake manifold leak syndrome). It leaked small drops overnight, but not enough to cause this breakdown. I just wanted to share this to all LT1 owners. Any comments is greatly appreciated. See pics. Thank you.

 

wow that is crazy the only thing i can think of is to check your vin# maybee it has been reported a lemon(bad casting,drunken assembly worker..ect.) other than that i will tell you the real reason .... you must use mobil 1 full synthetic oil, LT1's hate regular oil
the oil film probably caused to much friction, also a good thing to do when you hit 80,000 miles is to use RXP carbon reducer, i have seen my pistons and chambers before and after using it and it looks 50,000 miles younger from doing so. sorry again about the problem, and do not be discouraged by that LT1's are verry strong engines, i have 2, one with 120,000 miles with only a few mods and i still dynoed 310 hp and 335 tq

 

Holy moly that thing is blown to pieces,sorry to hear that man. Quick question did you buy it new or used,if used maybe it was driven really hard. I own a 93 with 155,000 miles and it still runs like a scalded dog.

 

Sorry about your engine, LT1's are pretty stout and usually wear out rather than break. I suspect you spun a main bearing and jammed the crank, causing it to break. That's an impressive break, haven't seen a good one like that in ages. These engine are built with very tight tolerances and destroy regular oil. I don't know the reason why GM does not require syntetic oil in Camaros but mandates it in Corvettes, especially since Corvettes have 4 bolt mains vs 2 bolt mains in Camaros.

 

The car was purchased 10 months ago used from a private seller (doctor) that had 86k miles then. Interestingly enough, a neighbor of mine share the same problem. In his case rather, he took the LS1 up to 150 mph when it locked up on him. So an LT1 and an LS1 down within the same week. How much does it cost to get a dyno on a vehicle? I'm trying to move forward but thanks to all that replied! I appreciate everyone's input.