Mechanical smell????

RobWales

Well-Known Member
Joined
21 Sep 2006
Messages
1,963
Location
Gran Canaria
www.3ksengineering.com
Hi All,
So it's now 6 months since I left the UK and I live aboard my 41ft Viking sports fishing boat out here in Gran Canaria....
My boat is spotless the bilges are clean and you could eat your dinner off my twin Detroit 2 strokes..
It's a warm climate here hence the move but on leaving the boat on an evening to go for a few beers I return and upon opening the cabin door......
Yup there it is again...... what I can only describe as a mechanical odour in the salon!
Main door has been closed but salon windows left open but rarely an evening breeze to move the air internally....
I notice nothing daytime when the everything is opened up but only upon return to a warm salon (main cabin)
Not overpowering i should add but just wondering why?
Anyone else experience similar?
Engines are directly under my salon which is carpeted.
Any thoughts insights Welcome?
Regards, Rob.
 
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I’m not sure what you mean by a mechanical smell but as per a thread I started yesterday a stinking smell in my boat was due to faulty batteries producing some kind of hydrogen sulphide gas.
 
I Think I know what you mean Rob

I cannot say that my bilges are clean and Shiny and the engines are not currently but i'm working on it... however I get that same smell - I can only assume its from the Crankcase Ventilation which although gets sucked back in via the engine, I think it still settles in the engine room and fabrics and lining etc.. kinda like a faint greasy oily type smell.. From what I know about the DD - I would assume they blow a bit more than my 6btas - is there any type of Closed CCV for the DD? or are they closed as standard? - I'm currently looking at dropping a Mann Hummel provent on mine to reduce any deposits from the CCV,

Steve
 
+1 As Piers says its probably always there but a hot afternoon draws it out.
Have you tried taking the carpet out one afternoon and seeing if the smell is stronger or weaker when you return. Could just be oil fumes etc trapped in the carpet fibres. New/or seriously cleaned carpet might help.
 
Crankcase vents have been modified at some time in the boats history allowing them to discharge into the exhausts...
Defo not from the batteries as it's not that rotten egg smell....
Carpet though looking very clean could I guess be the culprit?
And yes you're correct it's probably always there but only noticeable after a couple of hours away from it....
Cheers....
 
Engines, especially clean or new engines do have a hot metal and whiff of oil perfume to them. I love it. Unless its over powering signalling something wrong I'd just sit back and revel in the aroma of the beasts. If it is OTT do you run with blowers on, if not it might be an idea.
 
Not overpowering tbh, just wondered really if this is a common thing as all my previous boats being smaller I've never owned one with the motors directly below the salon....
And with the ambient temps out here quite high I always run with the blowers on even at trolling speeds..
 
By your own account the ER is spotless. I'm assuming no engine alarms or faults thrown up and no fluid loss. I wouldn't be overly concerned if it's just engine smell. Exhaust fumes, burnt, electrical fumes yes I'd be concerned.
 
Rob, These Detroits have a couple of places where there will be some residue coming out of the engines ... and as owning Detroits onboard and having a spotless engine room is very difficult, your source most likely will be; ...

Carbon resedue drained from the airboxes.... these are open to scavenging ports in cylinder liner and drain condensation outside the block (pipes run at front and aft of the block, near the airbox covers) and usually is connected up to one or two containers (or trays) collecting the dripping condensation. These pipes are closed by pressure valves when there is pressure in the airbox(engine with blower running) and opens up when engine is stopped (no pressure in airbox from the blower). As these are two strokes, there will be some air curculation in the airbox as there is passage from intake to airbox, thrugh scavenging port and through open exhaust valve. this will of curse cause condensation in the airbox as engine cools down, hence the drains being installed. With your hotter climate, if it drains into trays, then the water will evaporate and you will be left with some carbon deposits in the trays ...

Another source could, as others have indicated, the crankcase breathers... these are usually led up to the air intake,which if simple foam, catches the oil damp with the inevitable result becomes a bit damp with oil ... or if you have air seperators installed, then the oildamp is seperated and is caught in a container.

EDIT: Forget the latter as you have modified crankcase vents..
 
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