View Full Version : Hole in #8 Piston

07-21-2013, 06:12 PM
I am new to the forum and do not know if this has been talked about. I have a 2005 Matercraft X45 with an Indmar 5.7 MCX HO with 220 on the engine. The engine failed about 2 weeks ago after teardown I discovered a hole about 3/8" in #8 piston other cylinders on that bank looked good. It appears that #8 was running lean and detonating. Other cylinders do not show signs of detonation. My thoughts are week fuel injector or air leak causing detonation. Has any else has a problem similar to this? Any thoughts or feedback would be greatly appreciated.

07-21-2013, 07:51 PM
wow.. something to add to maintenance list... inspect fuel injectors.. yikes... sorry to see this... does this mean you have to machine all cylinders or just the one and replace one bad piston?

07-22-2013, 01:51 AM
Not sure of cause yet. I am still doing research. I have ordered a new factory long block but don't want it to happen again. That is why I am wondering if anyone has had a similar problem. Again any input would be helpful. I could have had this engined rebuilt but the cost of new GM long block was not much more .

07-22-2013, 02:41 AM
I would get fuel injectors flow tested

07-22-2013, 03:20 AM
I appreciate the input. Does anyone know a good source for flow testing. I was planning to put a new set of injectors in because they are only about $350 per set. But you are right I still need to know if the injector was the problem.