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How long for plug wires

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matta0413

Contributing Member
First off I want to thank everyone for the input on my one engine running hot. I think I have resolved that problem. Last night while running the boat at the dock I notice the port motor transmission really making that clanking noise at idle. Kick it up a few hundred RPM and it goes away. So in the quick research I have done this morning I am learning that is a sign the engine may not be running 100% efficiently. I have 8.1 MPI's model year 2002. All electronic ignition. How long should a set of plug wires last. The plugs were just changed but the wires I am guessing are original just like everything else on this boat.
 
i think you have the COP setup....no wires

If the clanking is in gear, at low RPM and goes away with a RPM bump up, it could be the damper plate's springs being worn out.....could also be a dead cylinder....a scan tool would be helpful for the latter
 
makomark said:
i think you have the COP setup....no wires

If the clanking is in gear, at low RPM and goes away with a RPM bump up, it could be the damper plate's springs being worn out.....could also be a dead cylinder....a scan tool would be helpful for the latter
Click to expand...

What is a COP setup. My 2003 8.1L Crusaders have ignition wires from each of the eight coils.

Matt, If I pull one wire off a plug the engine/tranny when in neutral and at idle will make that clanging noise.
 
Thanks Eric, that is what I am thinking. Gonna check it out later today. I am going to replace all of the wires as well as I am sure they are original. I am not sure what the COP setup is Mark is referring to. He actually has me second guessing whether or not I have spark plug wires.
 
Eric, I just looked it up. COP is Coil On Plug. So now I know what Mark is talking about. I do not have that. I have plug wires.
 
Coil on plug...get it. But the coils are mounted on the intake manifold near the fuel rail with wires going down to the plugs. A set of 8 has 4 wires of one length and another 4 of another length.
 
Erich - thanks for correcting my flawed thought.....so many variations in my old memory....

Some wires will last for years, others won't go more than two....best check is to measure them with an ohm meter while shaking them around....a bad wire will should you the make and break...a good wire will about 3000 ohms/foot
 
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Well I found the issue with the tranny clanging. It was a wire off. I replaced them all anyway as the ones that were on there were aftermarket and not Crusader wires. So fire it up and it ran nice and quiet. But I am back to my starboard engine running hot. I fired up both motors at the same time, both were idling nice at 140 degrees. Then i took out the temp gun and the risers (elbows) on one motor were at 90 degrees and the starboard motor was at 110 degrees. Why would there be a 20 degree difference. The entire cooling system has been replaced. New risers, new oil cooler, new water pump, new coolant, had heat exchange cleaned. What else could there possibly be??? Tomorrow morning I am going to by pass the raw water pickup and run it off the flush bucket. I am stumped!!! Could the heat exchanger be bad even though it is clean? I may try swapping them.
 
Did you back flush the oil cooler, When a water pump impeller breaks, pieces can collect there and hinder the flow of raw water through the system.
 
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