Ok, so your running WOT in a boat which I will assume has thru hulls and you "HEAR" a "LOUD" ping????and it still runs.
Chit dude, you just won the lottery. The Gods are telling you something for sure. Pull it out and tear it down BEFORE you blow it up real good.

Cylinders 2and 4, 3 and 5 should be just about ready to go blow torch when the head gasket fails. At 400 hrs. you are on borrowed time. Never mind that the valve train is worn out. Torching a block is a spendy thing to do and 500efi's are infamous for it when they get hours on them.

I hear some guys brag about how thier stock 454 and 502's reach 1000 and 1200 hrs with no wrenching.They say i just change the oil and run it. It seems so unbeliveable

Its not unbelievable when you have low lift cams, low spring pressures, and lower compression.

Just pull the heads because the valves and valve guides will need work as well as the head gaskets

Yeah,,,, I COMPLETLY misread that !!!!! Thought you meant use that to check for broken springs !!!

It was early,,,sorry !!!!

+1

Airpackeer is right on the money (lottery) with the head gaskets. Those things need changed. You can just change the springs and see how many are broken, but it's just a matter of time before the gaskets blow. Infact there is a good chance they are already leaking between those cylinders.

Hi,

Just learning about the 500EFI motor and reading this thread. I am thinking about buying a boat with a 500EFI motor that has 350 hours on it, do you think it will need valve springs soon?
I thought it was the carburated 500 HP engine that was prone to valve spring problems.

They are all prone to valve spring failure. To answer your question, yes it is ready for springs at 350 hours. Especially if you are just buying it. You don't know how it was run, how well or not it was serviced, etc. Sure, you can scan the ecm to see the hourly breakdown, but that still doesn't tell you how it was treated in general.


Wet Whistle (Nick), hope all of your parts showed up and that is everything you need. If I can help any more, don't hesitate to contact me. Thanks again for your business.
Eddie

Update: I got it all done and there was no broken springs but the head gaskets did look like **** between the cylinders. I also had the valves and valve seats reground as they didn't look the best.

So head gaskets definatley need replaced but the valve springs not so much. However you might as well since your in there.

Thanks for all the help guys!

So is it running again and did the sound go away, or are you still chasing the original ping sound?