Engine smell in cabin when boat is tarped for the week (350 i/o)

[Bob Sander]

When I tarp my boat for the week, I notice a slight engine smell in the cabin when I open it up on the weekend. I do have shore power at my dock and I was toying with the idea of running a small exhaust fan in the engine bay during the week (connected to shore power).

We use the boat for among other things, for overflow in sleeping extra guests at the cottage. It's not nice having that engine smell in the cabin for the first couple of hours of occupation.

Are other people running into this? What are you doing to combat the issue?

 

[Bondo]

Ayuh,...... So how filthy is the engine room,..??
Unless you have a leak, or spills, there really shouldn't be any noticeable oder,.....

 

[Bob Sander]

Actually it has just been cleaned and painted after a rebuild... which is kind of why I'm asking now. I still have to button up the wiring, so now is the time to do it, if I'm going to do it.

Still, it wasn't too bad before either though

 

[Bondo]

slight engine smell

Ayuh,..... Then describe "slight engine smell",.......

Gas,..??
Oil,..??

 

[tpenfield]

Yes, engine smell as in paint (from a new engine) or engine smell as in fuel/oil?

 

[Bob Sander]

No, it's not a paint smell, or even mold/mildew for that matter. It just smells more like a garage in the cabin area.

Now the boat was bought used and fully closed and tarpped on a trailer in a backyard for a number of years. I wonder if it's just the "garage" smell simply permeated into the cabin fabrics and such. All that is getting renewed though next Summer.

 

[Lou C]

How do your fuel lines look/feel? They can be cracked and not actually leak liquid fuel but can leak vapor.
Looks like you have an OMC Cobra.

 

[Bob Sander]

How do your fuel lines look/feel? They can be cracked and not actually leak liquid fuel but can leak vapor.
Looks like you have an OMC Cobra.

Well, they're certainly all good now after the refresh, but I didn't see anything too alarming even before... just a decade of grime and such
I do have a partially blocked view of the engine bay (blocked by the seller's head)... maybe you can see something which would cause the smell.
(Now I will say my wife said it smelled a little better since the engine bay refresh, but I sort of attributed that to being that I had all the ports open for a week or so.

 

[ahicks]

I'm wondering about your bilge blower/venting situation. Is it possible your canvas is covering the intake or exhaust side of that up?

 

[mr 88]

I would pressure test the tank. You should be getting ZERO smell of gas , period. Vapors are what cause explosions and you have that going on.

 

[Bob Sander]

I'm wondering about your bilge blower/venting situation. Is it possible your canvas is covering the intake or exhaust side of that up?

Both vents are open, but of course no fan running. The present fan is on battery. I suppose I could run it. There is a charger on the battery so it won't go dead. I don't like taxing the battery though. Our cabin is pretty isolated and there is no one up there during the week so if the charger fails and the battery dies, the auto bilge pumps go too.

 

[Bob Sander]

I would pressure test the tank. You should be getting ZERO smell of gas , period. Vapors are what cause explosions and you have that going on.

It's not really gas that's being smelled, but that's a good point. That tank should be tested.

 

[ahicks]

They have solar powered vents. Likely won't work with a pile of snow on them, but might help out otherwise.

 

[mr 88]

Take a pressure washer after dousing everything with Purple cleaner and let er rip. On a side note ,what the heck is engine smell if gas is not involved. Of the 10 inboard - I/Os I've owned I cannot remember ever having a engine " smell " other than gas .

 

[Grub54891]

I think it's time to shampoo all the carpet, headliner, everything related every nook and cranny to eliminate mold or other strange dirt. Boats are wet no matter how dry they seem.

 

[Bob Sander]

I think it's time to shampoo all the carpet, headliner, everything related every nook and cranny to eliminate mold or other strange dirt. Boats are wet no matter how dry they seem.

Thanks.
I think that's what I'm leaning to at this point. Clearly by the comments this is not normal, and I guess that is what I was looking to find out.
The project on the table for next Summer is a cabin refresh including new carpets, cushions, fabrics, etc .... so I think I will hang on till then. I may be dithering over nothing here since the problem may be gone with the refresh. It's probably just.... "old" that I'm smelling.

 

[Bob Sander]

Looks like you have an OMC Cobra.

Sorry, I missed this.
Yes, OMC cobra 5.7 4barrel.
It's an '87 Ciera 2755

 

[Lou C]

Same here. I've had it almost 20 years. Very few repairs to the drive and transom mount. I bought the special OMC tools to set up the shift cable and taught myself to do it in an afternoon. It shifts very well and has been very little trouble.
I did do a top end overhaul on the 4.3 V6 4 years ago but that was caused by a bad overheat 3 years before then. As it turned out it was just as well because the cooling passages in the cyl heads were getting thin and could have caused HG leaks or even a hydrolock if they rusted though all the way (salt water use). So based on this in my use a raw water cooled cast iron inboard is good for approx 15-20 years of use. After that, replacing the original cyl heads with a reman set will give the old engine a new lease on life, the blocks rarely if ever rust though here.

 

[QBhoy]

Hi. I’d say that when a boat is out the water and not sitting the same way as it does in the water…all sorts of weird things happen. Water from the bilge doesn’t stay in the bilge and can run forward. Leaks can appear that weren’t there in the water, just from the boat not being supported the same way the water does. Make sure it’s sitting stern low, as it would in the water and plenty of ventilation.

 

[Bob Sander]

Same here. I've had it almost 20 years. Very few repairs to the drive and transom mount. I bought the special OMC tools to set up the shift cable and taught myself to do it in an afternoon. It shifts very well and has been very little trouble.
I did do a top end overhaul on the 4.3 V6 4 years ago but that was caused by a bad overheat 3 years before then. As it turned out it was just as well because the cooling passages in the cyl heads were getting thin and could have caused HG leaks or even a hydrolock if they rusted though all the way (salt water use). So based on this in my use a raw water cooled cast iron inboard is good for approx 15-20 years of use. After that, replacing the original cyl heads with a reman set will give the old engine a new lease on life, the blocks rarely if ever rust though here.

Yeah, this boat has spent its life in fresh water so that makes a big difference. It's in really top condition for a 34 year old boat, and clearly someone has given it a (mechanical) refresh once before too. In fact I think that's why it sat for a number of years. When I opened up the motor I found YEARS worth of sludge in the bottom of the oil pan, but then to the other extreme, there were BRAND NEW main bearings, rod bearings, and rings!?! They had maybe 20 miles on them. But when I put the heads back on after inspection and did a quick hand compression test, the number one cylinder had ZERO psi. Opened it back up again and found the number one intake valve slightly bent. Checked the top of the piston, and sure enough, the ole' tell-tale mark on the top of the piston (intake valve hitting the piston).

I think what happened was that someone else tried a rebuild on the motor, got the valve timing marks wrong, spun it by hand, bent the valve, corrected the timing, but then didn't realize that the valve was bent. Got it all together back in the boat... boat in the water... and it ran like crap! He probably got frustrated at that point... stuck the boat in the back yard and moved onto other projects.