Oil in exhaust? - Page 2 - SailNet Community
LinkBack Thread Tools
post #11 of 15 Old 02-11-2013 Thread Starter
Learning Fast
Join Date: Aug 2010
Location: S.F. Bay Area
Posts: 41
Thanks: 1
Thanked 1 Time in 1 Post
Rep Power: 0
Re: Oil in exhaust?

Great explanation! On a 2 day cruise we just got back from, I saw both smoke symptoms. Black when I tried higher revs and thin grey smoke at low revs. I'll look into cleaning something and get some help. The boat speed was fine & as anticipated at whatever RPM I tried, so any mud on the prop is long gone.
Outrageous is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
post #12 of 15 Old 02-11-2013
Senior Member
celenoglu's Avatar
Join Date: Dec 2008
Posts: 738
Thanks: 1
Thanked 18 Times in 17 Posts
Rep Power: 9
Re: Oil in exhaust?

oil in exhaust is generally from the oil cooler. Sea water cools the oil and because oil pressure is more than water pressure, oil passes to the cooling water and finally to exhaust.
celenoglu is offline  
Quote Quick Reply Share with Facebook
post #13 of 15 Old 02-11-2013
Senior Member
Join Date: Jan 2013
Location: Montreal, QC, Canada
Posts: 363
Thanks: 0
Thanked 14 Times in 13 Posts
Rep Power: 5
Re: Oil in exhaust?

Your diesel could use a decarbonization via the fuel tank and the crankcase oil. Improvements will be noticable quit soon after using "Seafoam", obtainable from any automotive store.
sony2000 is offline  
Quote Quick Reply Share with Facebook
post #14 of 15 Old 02-11-2013
Glad I found Sailnet
Bene505's Avatar
Join Date: Jul 2008
Posts: 3,820
Thanks: 14
Thanked 51 Times in 50 Posts
Rep Power: 10
Re: Oil in exhaust?

Did you see oil on the water? If not, then you probably aren't exhausting oil.

Other than that, black smoke can mean barnicles on the prop. (At haul, out, I had 6 feet of line wrapped around the prop.)

I suggest you buy a mask, fins and a snorkle (and wetsuit). Like owning a Mast Climber, it pays for itself quickly.


Great minds discuss ideas;
Average minds discuss events;
Small minds discuss people.
The best minds discuss sailing (and a little bit of politics). I don't know why. It's a mystery!
Bene505 is offline  
Quote Quick Reply Share with Facebook
post #15 of 15 Old 02-12-2013
Senior Member
Join Date: Oct 2009
Location: Gloucester, MA
Posts: 586
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
Re: Oil in exhaust?

Have you always seen grey smoke at lower revs? If you haven't, check to make sure everything else is normal like engine operating temperature.

Have you always seen black smoke at the higher revs? A little bit of black smoke at high loads is perfectly normal on older diesel engines. They allowed them to overfuel a bit to get the horsepower rating up, the newer ones don't do this because of emissions. The only real downsides to it are it is worse for the environment, your mileage will be worse, and you can damage pistons and valves in extreme cases with high exhaust gas temperatures. If the black smoke is new and everything else being normal such as the boat speed versus the rpm, the first thing that I would look at is the air filter, a plugged filter will cause this.
klem is offline  
Quote Quick Reply Share with Facebook

Quick Reply

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
Oil in my exhaust Coronado35 Diesel 5 05-31-2012 11:54 PM
Yanmar YSM-8 Exhaust ? rjg23 Diesel 7 08-11-2010 12:10 PM
Crystals in exhaust dhornsey Gear & Maintenance 5 03-24-2009 11:25 AM
Wet Exhaust Hose 1970Columbia34 Gear & Maintenance 1 03-09-2009 08:40 AM
Wax job and exhaust smoke grinfax Gear & Maintenance 3 10-26-2008 08:19 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome