Fuel in exhaust (Volvo 2003)

A

AquaholicM31

Active Member
Joined
9 May 2016
Messages
55
Visit site
Hi All,
Searched the forum but no luck finding an answer.

My boat has a Volvo 2003 which starts easy even in middle of winter, doesn't burn any oil, runs smoothly and quietly (well as good as a 2003 gets). So in all aspects no issues with it.

My problem comes with the exhaust which seems to contain un-burnt fuel. When the engine is tied up running in neutral it leaves a 2m circle of fuel on the surface of the water around the exhaust outlet. I assume the same happens when motoring but obviously this is difficult to see as the water is moving.
Exhaust never gives any black smoke at low or high revs but does always have a small whisp of white smoke which i think is usual for these older engines?

Any ideas what could be causing the unburnt fuel and where i should start my diagnostics...

Many thanks.
 
AquaholicM31 said:
.
My boat has a Volvo 2003 which starts easy even in middle of winter, doesn't burn any oil, runs smoothly and quietly (well as good as a 2003 gets). So in all aspects no issues with it.

My problem comes with the exhaust which seems to contain un-burnt fuel. When the engine is tied up running in neutral it leaves a 2m circle of fuel on the surface of the water around the exhaust outlet.
Click to expand...
If that's your only problem, I wouldn't be worrying at all.
Perhaps a bit more specifically, I can't see an engine as old as that not exhausting a tiny bit of lube. oil, or maybe it's slightly over-fuelling at low load.
A very little oil goes a long way on the water surface!
 
Good point, maybe I am worrying over nothing considering how well it runs and the age of it.
My OCD coming out to try and make it perfect, wondering if there was anything i could 'tweak' to make it better.
 
When were your injectors last serviced, you may have a dribbling one. Also check for a slight weep of diesel around the top of the injector after running, there is a copper seal in there which can cause issues if misaligned.
 
Have exactly the same problem, became more obvious when I replaced the exhaust neck.

Await input from our learned colleagues.

An engineer from a Volvo agent suggested it was time for a new engine. But it runs economically, 2,5 litres per hour on the average of the last 500 hours. A little oil, maybe a few hundred CCS over 100 hours.

Will watch the post with interest.
 
We had the same issue on my dad's M31 hence the post about the injectors. You will probably find the exhaust valves are coked up and leaking slightly which also contributes to the issue.
 
The VP2003 in my M31 is likewise a good starter. A few years ago the engine had to come out fo9r a hole in the sump and while on a bench I had the top end overhauled and the injectors serviced. A slight bit a white smoke but no fuel on the surface.

I wouldn't worry about it until there was a marked drop in performance or a big increase in oil or fuel consumption.
 
Thanks for all the posts and the reassurance to leave it alone.
I did think about the injectors but after reading about the copper sleeves i am really hesitant to go down this route if i don't have too.
Now i'm not tinkering around with the engine i can go out sailing :)
 
FWIW, Drifter (1988 M31MkII, VP2003) also leaves a bit of a rainbow behind her. I hate the idea of knowingly polluting the sea, but I did in fact pull the injectors (without having first read the various posts about the perils of doing so) while investigating a different problem, and had them serviced. The rainbow is exactly the same as before.
 
We've had the same experience as everyone else - a tiny amount of oil or fuel in the exhaust is completely normal for these engines. One thing that has helped on ours was to ensure all the banjo joints are well sealed, the head bolts properly torqued (they should be re-torqued after 100 hours running if you've had the head off) and the valve clearances correctly set. Ours still emits a little white smoke on starting, but it soon clears. It also starts very easily now - I think tightening up all the banjo joints may have eliminated a tiny air leak.
 
You must log in or register to reply here.

Share this page

Top