Optimax 2.5xs

[nickens21]

Serial number is OT998968. I have been running premium plus oil in it since I have had it. My compressor just went out at 410hrs. Several have recommended going to the DFI oil..... Thoughts??

[Fishinmymission]

Photos that others have posted of failures has shown spalling on the compressor pump which eventually leads to debris generation, cracks and or seizing of bearings. Spalling is indicative of too high a stress and it has been well established that these early compressors had a bearing design(or was it manufacturing cant remember) flaw. I have yet to see photos with heat tinted metal or coked oil or galling that would indicate lubrication contributed to a failure. I highly doubt the different oils make any difference at the compressor pump.
Take it apart and post detailed photos of the air compressor so we can all learn about the failure. I can even offer any input from my experience in failure analysis.

On that note i was taking my plastic intake cover with the filter for the air compressor last weekend and 25% of the rubber grommet that seals the cover to the compressor was gone with more of it cracked. It almost def broke off in small pieces over the last two years with vibration and rubbing was all ingested by the air compressor pump. Hopefully doesn't cause any issues lol.

[Motv18]

Merc recommendation change was to full synthetic dfi. It has added cleaning for how dirty they run on high octane Ethanol free.

The t3wc tw3c whatever didn’t change

if yours is the single bearing yep if it has double bearings that’s a new one.

Pretty much means a whole air side and direct injection tear down. Fuel side is fine normally but while the rails out many get the fuel injectors cleaned as well.

[JPEROG]

Clean your fuel system-lines, rail, fuel and air injectors (have them flowed and flushed) then get a new style compressor. If you end up wanting to sell the motor, let me know (I am collecting parts and they only made 100 of them).

Joe

[nickens21]

I have a new compressor on order. The old one didn't entirely go out yet. Started making noise as I was waiting to load boat up on trailer. I contacted Mercury about the oil. They said to stay with the Premium Plus oil....

[Fishinmymission]

Can still shed wear debris into the fuel rails before it catastrophically fails. You should still open it up to look. Did you verify that it was actually the air compressor making noise by taking off the belt and feeling that air compressor flywheel was loose?
My enigine was just making a loud banging sound and I thought air compressor but when i checked it out one of the alternator mounting bolts was actually loose.

[nickens21]

Yes... I did take the belt off and check the alternator and idler pully. It was for sure the compressor. Yes Ill be sure to get the rails and lines checked to be sure. This engine has been great. Hopefully I'll get many more hours out of it after I get the compressor fixed.. Thanks for the suggestions.

[hsbob]

i talked to a merc racing tech in 2004 about this issue. at that time they said that the qualification testing was done with premium +. they recommended that oil [P+]. but the dfi was a sub for the P+ .

i have 2 2004 200xs motors and have only had an alternator failure. these are on a voyager and vegas hydrostreams so they are noy babied.