White furry corrosion

[Elgineddie]

Hi team,
Looking to learn what this furry, white, powdery corrosion is on various parts of my Atomic 4. I'm guessing it's, well, I don't know! I searched for "white" and "corrosion" and didn't find much. Thoughts?

Oh and I'm starting to run down Don's troubleshooting list of how I may be getting some small amounts of water in my oil and this led me to check my water pump weep holes which have this furry growth. I wouldn't say it's of a clogging consistency, more powdery.

Thanks,
Ed

[JOHN COOKSON]

Are you RWC in salt water? Slow leaks with the water evaporating leave salt crystals behind.
Water in the oil sounds like an exhaust system problem or a defective seal between the water pump and the accessory drive.
Looks\sounds to me like you need a new side plate seal and new water pump seals.

ex TRUE GRIT

[Elgineddie]

Yessir, raw water cooling in salt water. I haven't run the boat in 8 months and I thought I did a 5gal fresh water flush before I left (I usually do when I know I'll be gone more than a month). But yeah, she sits in salt.
Thanks,
Ed

[Al Schober]

What's leaking there are the 8 bolts holding the cover plate. You'll find corrosion below that plate right down to the top of the oil pan.
Remove the cover plate and examine it for corrosion on the back side. You may want to replace it with stainless from Moyer. Clean up the bolt holes (3/8-16 tap) and install studs. Moyer has a kit or just use stainless set screws and JB Weld.
If you're in salt water and are happy with the A4, glycol cooling is highly recommended.

[ronstory]

Unfortunately MMi does not offer the stainless version anymore. Otherwise our new engine would have one. ;^)

Their current offering looks to be:

https://moyermarine.com/product/water-jacket-side-plate-with-lug-ovwj_07_138/

with the basic plate with the welded in support for the alternator bracket.

[DDO]

There's a nice photo of "white fur" in my post "Here's a photo for you..." in Exhaust topic. I replaced the side plate last year with the Moyer part, and it's a good project because you can inspect and fix up that side: replace the water hoses there, put a cap over that alternator output, and such. The holes did not line up with new plate, so evidently had been worked on before and those were "repaired holes", but we patiently shaved away until the bolts could go through. You will get to clean lots of black junk out of there, just bring out what you can and don't worry. Annual vinegar soaks will keep it (black goo in water jacket) under control.

[Elgineddie]

Thanks, DDO. I'll certainly give that a read.

There's a nice photo of "white fur" in my post "Here's a photo for you..." in Exhaust topic. I replaced the side plate last year with the Moyer part, and it's a good project because you can inspect and fix up that side: replace the water hoses there, put a cap over that alternator output, and such. The holes did not line up with new plate, so evidently had been worked on before and those were "repaired holes", but we patiently shaved away until the bolts could go through. You will get to clean lots of black junk out of there, just bring out what you can and don't worry. Annual vinegar soaks will keep it (black goo in water jacket) under control.