Limp mode

[UNSTUCK]

Ok, hear me out on this everyone as we've seen it occur 100%:
What oil are you using? I ask because when Mercruiser first introduced the cat exhaust systems we would have multiple O2 sensor codes and alarms we couldn't figure out (on at least a dozen customer boats) within a few hours of an oil change and no one had an answer. I ended up having a conversation with a Mercruiser Racing engineer and here's what we learned:
Using regular dinosaur oil (non semi-synthetic or synthetic oils but regular petroleum based oils) on a catalytic converter engine is a no-no because there is too much phosphorous in the oil. During the combustion process this phosphorous is then passed downstream through the exhaust and wreaks havoc on the O2 sensors. Simply changing the oil to semi-synthetic or full synthetic and replacing the O2 sensors solved the problem every time.

It's good you found success. Seems very odd to me that switching to synthetic solved the problem. Cats and O2 sensors have been run in engines long before synthetic oils became popular. Maybe you were just having issues with your particular oil. I'd probably be more concerned about the oil/phosphorus even getting into the exhaust system to begin with.

[boatwakes]

Mercruiser regular petroleum oil is no longer recommended (by Mercruiser) for any engine in their lineup as a result and all marinized engine brands only recommend synthetic blend oils now too. We were using their proprietary 25w-40 Dino oil when the problems occurred for our customers and we've since seen it happen with all non synthetic-blend oils in marine applications across all brands, FYI to the board as a result.

[sandm]

Seems very odd to me that switching to synthetic solved the problem. Cats and O2 sensors have been run in engines long before synthetic oils became popular.

I was thinking the same thing. woudn't it carry over into the automobile environment as well? marine and auto engines are basically similar other than the exhaust manifold having water run through them. would think if it's happening in a marinized engine it would happen in a car engine?

[Bamer]

I was thinking the same thing. woudn't it carry over into the automobile environment as well? marine and auto engines are basically similar other than the exhaust manifold having water run through them. would think if it's happening in a marinized engine it would happen in a car engine?

Don’t car engines run hotter (about 40degree) and the exhaust a lot hotter than boats. Higher temperature will definitely affect the chemical reaction occurring in the catalytic converter. More temperature = faster/more reaction.


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[sandm]

I believe they do however that's on the water recirc/thermostat side. would think that gas being expelled out of an exhaust port in a boat is the same burn temp as the exhaust in a ford raptor truck-or at least hot enough that the boat cats have been designed to compensate for any temperature variance. switching between synth and regular in cars does not come with the same issues- or at least it's not advertised and would think if it was an issue mobile1 would have a full-on advertising campaign to tout full synth for sales. what makes a boat different?

[boatwakes]

Fuel curves and camshafts are different between automotive and marine to include full time loads seen in marine engines vs varied loads in automotive engines. As a result, )2 sensor parameters in the computers are different and not interchangeable with automotive computers. I could go on for days but the question still remains, what oil is he running?

[Zackdogg]

Missing all kinds of chat!!

I’m not sure, whatever the dealer uses. I’ve always been told that syn is pretty much a waste of money, so I would have said standard if I ever had the choice. They never asked, so I assumed they use whatever Indmar wants them running, or syn so they could charge me more.

Either way, I don’t think it’s applicable to me, well who knows actually, but they’re telling me the O2s aren’t the problem, low fuel pressure is, and I’m positive the oil isn’t affecting the fuel pressure. They did tell me it was the O2s originally, I think in retrospect because they either didn’t know and wanted to give me an answer or they thought the O2s were the issue before realizing it was the fuel pressure the 2nd time they got it.

I will find out what oil was used, just so we all know, though..


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[UNSTUCK]

The camshaft in an Indmar 6.2 is the same camshaft that is in a Ford truck 6.2 according to my conversations with Indmar about it. While I do agree that in general a marine engine is more loaded in a given situation, my marine engine sees varied loads throughout a day on the water. Either way there are trucks out there that tow/haul all the time, and we could assume they would see similar issues. I haven't seen tune information from E-Controls so I can't say what, if anything, is different from the Ford tune. I have my doubts that much is different. Fords tunes work just fine at full throttle so why would E-Controls reinvent the wheel?