Motor soot

[saltygirl]

Good evening! My husband and I have a 1998 34 mkII. We are almost to our destination and noticed engine soot throughout the engine area. No alarms and the engine has been running fine and not hot for the last 200nm.  Any suggestions?  We have checked the oil every evening and have not seen this before. Thank you for your input, we are worried about completing our trip tomorrow.

[Ron Hill]

Salty : Sounds a though you have a problem leak with the exhaust riser.  Start at where the riser connects to the flange on the back of the exhaust manifold and look for leaks - while the engine is running.  Could be a blown flange gasket or the riser itself.

If you don't have water with the soot it's probably in the riser before the raw water mixes in with the exhaust gases going into the muffler.

Good luck tracking that down. 

A few thoughts

[Dave Spencer]

Celeste and Greg,
In addition to Ron's thoughts, although you said soot is all over the engine compartment, if the soot is primarily located near the front of the engine, it's possible that it is "belt dust" created by wear on the water pump /alternator belt if pulleys are even slightly misaligned (many are misaligned at the alternator). When you open the access door under the sink, is the water muffler covered in soot?  Are the hose and anything else you have stowed under the sink covered?  Soot smells in the area while you're operating?

[Ekutney]

Any exhaust smell at all?  Look under the head sink as suggested & see if there is any indication of soot at the muffler input or the riser where it goes into the muffler.

Have you noticed any change in water flow out the exhaust?

[saltygirl]

We ran the Motor and did not see any exhaust leaks. Soot was mostly contained to the engine compartment. Engine water output looked fine. Had too clean the air filter as it was covered in soot.

[Ekutney]

Where is the output of your crankcase going?

[saltygirl]

 After pondering on it all evening, we are thinking it could be from when we had to idle a good bit today waiting on railway bridges, locks and swing bridges to open. Maybe the carbon built up
We cleaned the sooty air filter and will keep checking on it...

[Ted Pounds]

I think Dave might have the right idea - belt dust...

[mark_53]

I'm thinking belt dust too.  Do you have an "upgraded" alternator?

[Ron Hill]

Guys : Belt dust is NOT found "throughout the engine area".

A thought

[saltygirl]

When we reached our new slip, we found that the exhaust riser was being held together by the insulating jacket.  We have been cleaning up a mess!
Today we are attempting to put on a new exhaust riser...
Thank you all for your expertise and advice earlier.

[Stu Jackson]

This may help you with tips & tricks:

http://c34.org/muffler-exhaust-riser-replacement-2015/