2000 280GSI Head and blockmelt down between #3 and #5 cyl

[homelite]

I had this failure. Just looking for a cause or if this is commom. 400hrs. 11 years old. Fresh water. Did not overheat. I thought i just blew the head gasket, but I totaled the engine. In installed a new long block and all seems good now, but the cause...... Makes me wonder. Just wanted to throw this out there to a marine mechanic that works on these every day, which I don't. Engine runs fine. No computer codes, etc. have 15 hrs on new engine, but like I said, the cause of the failure makes me worry a bit about it jhappening again. maybe it was just a bad head gasket and that's it.

I melted a groove in the block and head between these 2 cylinders.....

Thanks


Engine is 5.7 GSI PEFS. 4012002353. 3869059

 

[Maclin]

Re: 2000 280GSI Head and blockmelt down between #3 and #5 cyl

Without pics this is just conjecture on my part, but that sounds like a leanout or detonation condition, maybe a hot spot somewhere on the head causing detonation. The cylinders and pistons would have some telltale signs of that, like balls of molten aluminum hanging around, visible damage to top of piston. The bottom of the valves would show signs also. Maybe one of the injectors leaned out under throttle or maybe timing was off and that was just the leanest set of cylinders.

Got pics?

 

[homelite]

Re: 2000 280GSI Head and blockmelt down between #3 and #5 cyl

Thanks for the reply. I thought of lean, but it's throttle body injection so why just 3 and 5? Timing was ok so it wasn't that. I'm fussy with details as I am an ASE certified auto technician. I know the drill. I just don't work on marine applications everyday. I sure don't want to overlook something..... That's why I'm asking. I attached a few pictures.

 

[Maclin]

Re: 2000 280GSI Head and blockmelt down between #3 and #5 cyl

Looks like water getting in from the exhaust manifold maybe, causing some corrosion in the head/valve making a hot spot? That groove has the signs of looking like a blowtorch did it, I think that is hotspot type detonation (or nitrous gone bad!).


That one cylinder has what looks like a lot of water in it, is that just from disassembly? From the pics it looks like it is not the same cylinder as the matching head chamber with the rust.

 

[homelite]

Re: 2000 280GSI Head and blockmelt down between #3 and #5 cyl

The water is from disassembly (I think). I took the riser off and didn't drain the manifold first. I saw water drain in the exhaust part in the center. I waited 2 days to pull the head. When I installed the new engine, I obviously replaced both riser gaskets. Everything looked fine there. Like I said, it is only used in fresh water. I do have one question though... When I ordered the risers gaskets, I got 2 fiber gaskets (like I had from the factory) and 2 metal gaskets. I called the outfit where I bought the parts and they said they threw both kinds in the bag so I could use the ones I wanted. What gives here? Anyone know? Fiber or metal? Like I said, I used the fiber ones. I can add one more thing relating to the "tourch" look of the cast iron. When it blew, I was on full throttle trying to plane a 25' cruiser with 9 people total and 6 of them (college kids) were on two huge tubes. In other words I was under tremendous load for about 30 seconds. Perhaps this really was just a head gasket failure and since it went under such extreme conditions, it "tourched" the cast iron. I just don't think this is common. We never see this in the car world, but they don't operate under this type of load either. I am really interested in anyone's feedback on the different style riser gaskets.