Water in oil 2007 AR210 help!!

[Cambo]

when you took the lid off the air box did you see chocolate milk looking oil sitting in the air box cover ? This usually happens due to the additional fluid being introduced and the breather spits it out into the air box. The other thing that happens at idle you will see steam coming out of the pisser. I think the reason the breach occurs is from cavitation, as the aerated water flows through the cooling channels it does not cool properly causing the aluminum to fail.

 

[danzr1]

I have just tested the compression and its bouncing off 210, over 200. I think I will just change the exhaust manifold, take me 20 min to install it. I'll probably buy a new one.

 

[danzr1]

After changing the exhaust manifold with a new one. Problem is solved! Thanks everyone for your help.

 

[mragot]

Most common water in the oil issues are

Cracked block do a search
cracked head do a search
Exhaust manifold breach attached picture
Oil cooler leak


View attachment 221196

I had the same issue on my 2007 SX 230 Port engine. Milky oil. Compression in the 160-170 range on all cylinders. No issue with running. Found the same outer exhaust manifold with the same hole as shown above. Also the collector to Muffler joint had a bad gasket and both sides were badly corroded and certainly would exchange water and exhaust. Replaced all 3 parts with used from a jet ski and problem solved. Changed oil 8 times generally 2 quarts per change and the oil is now clear as new. Ran engine several minutes on hose to get them warm and circulate the oil well to wash out the old. Thank you for the pic.

 

[Cambo]

• Cavitation and air bubbles: When the impeller mixes air with water, instead of a solid column of water. Air doesn’t absorb heat well, so the cooling jackets may see “dry spots” or steam pockets even though the tell-tale (“pissers”) still show flow.
• Heat sensor vs. actual heat: Some Yamaha motors have had occasional sensor glitches, but they also rely on multiple signals. If the sensor triggered while the tell-tale still looked good, it can be tricky to tell if the alarm was false or if there was localized overheating.
• Localized overheating: Aluminum melts or deforms at a relatively low temperature compared to steel. If a vapor pocket forms in a cylinder jacket, that spot can get dramatically hotter than what the temp sensor sees elsewhere—enough to breach the metal even though overall flow “seems” normal.
• Limp mode: The ECU usually tries to protect the engine by limiting RPM, but if the overheat condition is short or localized, you might not feel full limp mode before damage occurs.