30 power twin diesel Volvo 200 - severe soot problem

[Mitchell Quintner]

We have severe black soot over entire back of boat after running
has anyone had this problem and what can be done about it.
We have tried running with engine hatch and windows open believing
it had insufficent venting, didn't seem to help any. Our engines
has less than 400 hours and have been serviced by a Volvo tech. this
year. We have only owned the boat this year so have no knowledge
of previous years.



ameloblast@aol.com

[Stuart Harrison]

Saw your comments re: diesel soot.

I have a CD 28 and have run it hard with Volvo diesel in Intra-Coastal Waterway from Freeport, Texas to New Orleans. And, cruised alot on SW Fla. Coast. I have had same soot problem. I just get in water and wash off back of boat with rag and elbo grease. I've noticed it comes right off boat if you react quickly. But, if you wait and let it set in (especially on fiberglass hull with chalking) then it is very tough to get off. So, I keep my hull always compounded down and waxed well, and I wipe or clean soot off the stern regularly.

I also bought a Bakke hand fuel filter to filter out diesel that I'm putting in my tanks, in addition to the two fuel filters (primary and secondary) I have on the engine. I'm really picky about fuel purity AFTER I had severe engine problems from taking on gritty, watered diesel at a bad boat dock near Port Arthur, Texas one time. I think fuel purity might have something to do with clean burning and low soot emissions.

Finally, I had a mechanic check my engine out. He said failing to run your engine consistently at proper RPMS can cause engine to carbon up inside, create soot problems and literally ruin valves, cylinders. He also said to make darn sure I re-checked my PROP size to make sure it was proper for engine make and size. Apparently, I was using a prop that was too big for engine, ran up RPMS, caused engine to work too hard and carboned up top of one of my cylinders - just about ruined my engine. I had the prop blade removed, ground down and re-balanced by a prop shop.

The mechanic told me some people can diagnose some engine problems by looking at smoke color. White smoke means one thing. Black - blue smoke means another. I don't know about this - sounds hocus pocus to me. But, he claimed some people swear by it. In my estimation, only a good mechanic will really know for sure.

Lots of travelled boats, I've noticed, have the soot build up on stern. That's a diesel for you. But, I think you can minimize it by cleaning hull, keeping it compounded/waxed, keeping fuel clean/pure and making sure your engine/prop are in proper running shape.

I'll be real interested in other comments for others on this subject. Soot is a real problem for me. But, I've just minimized and dealt with it as stated above. Otherwise, seems to be part of having a diesel.

Good luck,

SH



hdhlaw@hotmail.com

[Walt Bilofsky]

We have severe black soot over entire back of boat after running
has anyone had this problem and what can be done about it.
We have tried running with engine hatch and windows open believing
it had insufficent venting, didn't seem to help any. Our engines
has less than 400 hours and have been serviced by a Volvo tech. this
year. We have only owned the boat this year so have no knowledge
of previous years.

I had a pretty bad soot problem too, but it seems to have gone away. See <a href="http://www.toolworks.com/cgi-bin/tw/wwb ... d&8733">my earlier post</a> regarding a "miracle cure" which I still find hard to believe, but there it was. I haven't heard from anyone else who has had this problem, but if you have a lot of vibration at WOT (much more than at normal cruise - say 3200 RPM) then maybe you should have your couplings checked too.

Underpropping can also cause soot - as can resistance in the drive train or anything else that puts more load on the engine. Do you have 18x19 props? TAMD41B Volvos ought to hit between 3700 and 3900 RPM at wide open throttle. My book says 3600 but apparently Volvo updated the spec - maybe they were seeing some problems at the low end. My engines used to run 3650 at WOT when I got soot. What is your WOT RPM? If you are below 3700 look for resistance in the drive train somewhere - the problem I had with the shaft couplings, misalignment of the engine and driveshaft, worn cutlass bearings, etc.

As far as cleaning the stuff off the transom - I could never do very well with soap and water, but I discovered that ordinary combination fiberglass cleaner-polish works great. Just slop on and wipe/buff off, then go back and clean off the dirty spots with a second application. Don't understand why the soot doesn't just get embedded in the wax but it doesn't.

Since you are a new owner you might want to use this message board's Search function to pull up some of the previous posts on 30 powerboats. There have been other questions raised that you might be interested in.

We just got back from a trip across San Pablo Bay (north of San Francisco Bay) in 25 knots and a short chop to 3'. We got the CD 30 so we wouldn't have to worry about the Bay when it blows like stink, and this boat certainly fills the bill. We have had it six years and have no plans to change.

Good luck,

Walt Bilofsky



bilofsky@toolworks.com

[Tony Raymond]

Hi, I am actually responding to to Walt's previous note on fixes to his shafts and couplings. As it was already archived, I couldn't respond to it.
It just occurred to me that the couplings were worn out due to shaft whip, they were not manufactured that way.
They were worn evenly around as the shaft was probably pretty ballanced and straight so it was whipping in uniform concentric way. When the new gears were installed it probably aligned ok as there as consistant spacing between the flanges, just too much. Isn't spec 0.003" max.?
So, Walt you may have fixed the symptom but not the root cause. It looks like Robert Davee in a followup to your origional note might have found and fixed the root cause. That is, he stopped shaft whip by adding the intermediate bearing.
You can just immagine a discussion between Cape Dory and Diepetro-Kay in the late 80's that went something like. "Will the vibration due to the unsupported shaft length cause it to fail?" "No, it won't fail as it is within specification for a 1 1/2" shaft. It may vibrate a little more, but it won't fail"

Just my two cent's. I hope I'm wrong. But it's something to ponder as maybe another Y2k event.....

Tony



tony.raymond@worldnet.att.net

[Bob]

We have severe black soot over entire back of boat after running
has anyone had this problem and what can be done about it.
We have tried running with engine hatch and windows open believing
it had insufficent venting, didn't seem to help any. Our engines
has less than 400 hours and have been serviced by a Volvo tech. this
year. We have only owned the boat this year so have no knowledge
of previous years.

I believe that part of your problem may be in the fuel you are using it may be old. Try switching your fuel additive to MDC fuel stabilizer conditioner or some other brand, which specifically addresses sooting fuel problems caused by old fuel. Many of us buy fuel thinking it's fresh but it's been in that tank for quite a while and would benefit greatly from a cetane booster additive or other fuel stabilizer conditioners. I speak from experience, many years ago I served as First Mate aboard commercial offshore fishing boats. We would usually take on fuel once every 2 or 3 weeks running 24 hours a day unless we were in port. In one fueling I would take on between three to four thousand gallons of diesel fuel depending on how long we were out. In order to avoid down time on the engines I always would pour in several cans of fuel stabilizer conditioner to reduce sooting and waxing on the injectors and fuel pumps. In our business keeping the engines up and running was the number one responsibility of the First Mate, any down time was an impact on your paycheck. Fuel filter and oil change maintenance was performed regularly at the manufacturer's recommended intervals. Later when I left the fleet to become a service manager with a diesel service company I regularly would call on ship yards to diagnose diesel problems on ships, which 99% of the time was due to poor maintenance practices and poor fuel treatment or old fuel as usually was the case . Anyway that's my experience, keep the fuel filters clean and always treat your fuel because it's not as fresh as you would think it to be.

Bob
S/V Ranger
CD25D #144



rmalinka@spec.net