Have an 05 250TXRD. Bought the boat with an issue. At full bore for about 15 minutes at 5500-5900 RPM’s, motor drops by approx 500 rpm’s an reads check engine on dash. Turned out to be an exhaust cam sensor fault. Replaced that. Ran well for the last couple trips last year. First trip out this year, same thing. Dropped 300 rpms with check engine flashing. Experience from last year says slow down. Shut off motor. Restart. And be on your way. Code vanishes. Until about 15 minutes give or take at full bore. It happens again. I normally don’t run WOT. If I stay under 5200rpms It doesn’t happen. And you wouldn’t even know it does this. Marina says they cant find anything wrong. Anybody else have this happen? At $300-400 per trip to the marina and $200 per cam sensor. I cant really afford to pay somebody to tell me nothings wrong. Code isn’t stored on ECU.Now I’m Worrying about some underlying issue that nobody seems to be able to find.
All logged codes should store, if not store be in the pending category. sounds odd.
You say when code flashes you drop 500rpms, Not sure on Marine stuff, but should be close (i think? Chris?) If is was a critical fault engine should derate to just above idle.
What I would suggest first before throwing any more parts at it is take it to a factory dealer and have them update Computer/ Reflash it with current software and go from there.
Good Luck!
The exact fault code along with the list of possible causes from the dealer manual will tell you a lot. There is more than one reason for the cam sensor reading incorrectly.
I would be curious if the tone ring (metal part the sensor reads) were loose or damaged.
If the engine has a lot of wear the cam shaft could thrust too far away from the sensor at high RPM causing a weak reading.
They may seem pretty far-fetched, but that’s just two off the wall problems I’ve experienced with other engines.
*** World Cat 266 SC ***
Received some info today about it from Yammie tech support. In the interest of anyone searching due to same issue, I’ll post full conversation. Intake and Exhaust cam sensors on this motor are identical. Swap them out and see if problem follows sensor. If its a faulty sensor, code will change for 24 to 71 I believe. If it does. Its the sensor. If it does not. And the code 24 remains. Its the capacitors in the harness. And that needs to be replaced.
In my case, its probably not the sensor. I just bought a genuine OEM one less then half dozen outings again. Hopefully have an hour to drop in this weekend to test it out. I havent looked yet but the harness doesnt look like an inexpensive part lol.
Its never feels good to have to buy a whole assembly for one little part. I hope this gets you back on the water.
*** World Cat 266 SC ***
definitely doesn’t sound like a sensor issue.
that motor has variable valve timing, which is why you need the cam sensors.
that timing is controlled by a valve on top of the valve cover. it uses oil pressure to make the changes to the timing. I have seen the oil control valve cause similar issues.
www.teamcharlestonmarine.com
www.bombislandboats.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING