Yellow dust in engine room?

[hpeer]

Originally Posted by Paul L

On my 4jh3 the air cleaner was getting a white fluff on it. I figured it was just dust getting in. Turned out the exhaust insulation wrapping was degrading. Replaced it and the air filter stays clean now.

I have an oversized exhaust elbow because the engine sits below waterline, so I’m familiar with what you speak. But that is white and slightly covetous, not a yellow powder.

[hpeer]

Originally Posted by Boatyarddog

Any rust on those engine pulleys? Alternator?
Seems odd that it's focused more on one side in the front.
SV Cloud Duster

Agreed, and alternator was changed just before I saw the dust. I see no rust but I agree the alternator is suspect. Perhaps the cooling fins are blowing dust one direction. It’s a cheap 100A alternator, I’ve the origional 80A, recently cleaned and serviced, in spares. But still, alternator, yellow dust?

[Frugal]

Wood borers, termites in the woodwork?
A very common occurrence in bush housing in PNG. About wholemeal flour consistency.

[capngeo]

Originally Posted by hellosailor

If it is YELLOW yellow? Heavy pollen in the air accumulating in the engine space?
Been anchoring out under the jubjub trees?(G)

^^^^ My first thought^^^^^

[Catboat Willy]

We surveyed a Nonsuch 36 in the Florida Keys and saw a pile of yellow brownish powder forward of the foremost bulkhead . Our initial though was that it was a powder for killing roaches. Upon closer inspection it turns out it was termite 'fess' (the technical name for droppings) Those little critters had done a fine job of eating their way into the one inch thick plywood bulk head.

They had 'swarmed' through the hawser pipe, eaten their way through the marine plywood then laying their eggs on the bulkhead aft of the chain locker !
Research showed it happened in less than one week.
Nasty little buggers !

[Bill Seal]

Power post beetles? Sure hope not.
Powder Post Beetles - How To Kill and Get Rid of Powder Post Beetles

[hpeer]

I MAY have figured it out. Could not find source so I started engine. Found my exhaust mixer moving wildly. Because the engine is mounted low, below water line, it is a special very tall mixer. It had snapped a stud on the flange and was leaking exhaust.

I retightned the other two bolts and hobbled from Dominica to St Pierre. Yesterday I managed to get the remaining stud out, it had broken with a good bit sticking out, and replaced it with a bolt. I’m hoping that is the end of that. We shall see.