View Full Version : Fogging consensus on MCX

09-26-2011, 12:24 PM
Still trying to get this clear. Is it better to fog through the spark plugs, or not fog at all? If I do fog do I have to change the spark plugs, or are my new plugs from last year good enough? I have also read in places that I have to change the oil again, because fogging oil can get into the engine oil, please help.

east tx skier
09-26-2011, 12:27 PM
I do not have an MCX, but I do have an engine with a dry intake. I fog through the spark plug holes only. I change my plugs in the spring and do not change my oil again in the spring. This works for me. YMMV.

09-26-2011, 01:07 PM
I have an MCX. I change my oil in the fall, winterize and fog engine through the spark plug holes.

I don't change my oil in the spring, and I don't change my plugs every year either. Every 2 years for plugs for me (about 150-175 hours on the plugs)

09-26-2011, 01:47 PM
3. Fog cylinders using spray fogging oil.
Spray directly into carb or throttle body (TBI).
Or, if Multi-Port EFI (Dry Intake), spray directly into each cylinder through the spark plug hole.

09-26-2011, 02:35 PM
I change the oil and filter and take sample for blackstone-labs oil analysis, pull RV anti-freeze into engine, then pull 7 of the 8 plugs and fog. There is one plug on the starboard side, all the way back that is a pita to get at. You have to remove hoses to be able to get to the plug.


09-26-2011, 04:51 PM
Never fog. Change oil every 50 hours, no matter when that occurs (not necessarily before Winter or in the Spring, etc). But my engine never goes more than 6 to 8 weeks without being run.

09-27-2011, 09:17 AM
OK... so it looks like everyone fogs by pulling the plugs... what if i fogged through the intake last year? would that have done any damage? (i changed the oil mid-season this year, so even if the fogging oil got into the engine oil, its gone now).

09-27-2011, 10:47 AM
Dealer says fog yes if no O2 sensor, fog no if you have an O2 sensor. I fogged my 06 X9 MCX last year through spark plug holes, did not change plugs then or this spring and had no problems.

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09-27-2011, 12:32 PM
I was surprised to read in the Ilmor manual that they recommend fogging via the air intake.

10-02-2011, 09:33 AM
I did not fog our 2010...since everything I read states not to with the MCX with cats and 02 sensors.

10-02-2011, 06:49 PM
I fog through the intake. That is what Mike from MCOC told me when bought it as well as his lead mecanic at the time. No issues. I've heard of others also doing it through the spark plugs, but I have confidence in what they told me.