4108 blue smoke

[Tamar]

I know this is caused by burning oil, so worn rings and such. But should it clear when the engine warms up?

 

[scottie]

Is an old girl like that not expectEd to have a blue rinse?

 

[Tamar]

Is an old girl like that not expectEd to have a blue rinse?

But does the blue rinse wash out eventually

 

[n.herring]

I know this is caused by burning oil, so worn rings and such. But should it clear when the engine warms up?

I always thought blue is unburnt diesel on start up, black is oil burning on acceleration etc

 

[Portofino]

Worn valve guides is another way oil gets in .

Is any oil noticeably being consumed?
How many hrs are on them ?

 

[oldharry]

I always thought blue is unburnt diesel on start up, black is oil burning on acceleration etc

Unburnt diesel is white and very pungent. It can havea bluish tinge. Its caused by non combustion or failure to burn all the charge because the emgine is too cold to permit a proper burn. Low compression can cause it on startup too.

Black is caused by an over-rich fuel air mix, and is normal on hard acceleration, or various faults such as blocked or reduced air intake (filter blocked?), or overloaded engine (e.g oversized prop preventing the engine reaching full revs at full throttle. Can also be symptom of injector problems giving too much fuel.

Blue smoke is caused by the engine burning lube oil because of worm cyolinders, valve seal failure, or other faults allowing lube into the combustion chamber.

The exception is a runaway diesel which will emit huge clouds of dirty white smoke: had a van that did that, and incredibly. survived. back pressure had pumped lube via the breather into the inlet manifold. Once enoug had accumulated it fed the engine until it cleared the manifold. Fortunately it was not pushing enough to keep feeding the engine! A lot of that s diesel smog, because it is running too fast to burn each charge of diesel properly.

 

[Tamar]

[/QUOTE]

Worn valve guides is another way oil gets in .

Is any oil noticeably being consumed?
How many hrs are on them ?

It's not my boat, I'm posting for a friend who's not on here. I think they are the original engines from around 1978?

 

[scottie]

As I understand it’s
Blue oil
black fuel
i suspect that it has got progressively worse over time so time for compression check etc?

 

[asabay]

does putting no smoke into oil not stop it smoking and does it do any damage to engine ????

 

[oldharry]

??

 

[julians]

??

I presume he means this stuff

No Smoke engine Oil - best stop smoke oil treatment

doesnt look like a good idea to me..........looks like a way of getting an aging car that normally fails its mot on smoke emissions through an mot test before you quickly part ex it out to someone else.

If it does what it says it does, it'll stop the engine smoking (if its burning oil), but obviously wont fix the underlying cause of the smoking.

 

[westernman]

Worn valve guides is another way oil gets in .

Is any oil noticeably being consumed?
How many hrs are on them ?

Worn valve guides can be sleeved.

Stuck or worn rings can be replaced.

Otherwise, a rebore might be needed.

 

[asabay]

does putting no smoke into oil not stop it smoking and does it do any damage to engine ?

I presume he means this stuff

No Smoke engine Oil - best stop smoke oil treatment

doesnt look like a good idea to me..........looks like a way of getting an aging car that normally fails its mot on smoke emissions through an mot test before you quickly part ex it out to someone else.

If it does what it says it does, it'll stop the engine smoking (if its burning oil), but obviously wont fix the underlying cause of the smoking.

that's the stuff, i'm about to use it on my bmc engines to get me over the season [loch lomond], what's the best remedy for this and roughly how much will it cost per engine ????

 

[gordmac]

Perhaps try an "Italian tune up" before spending much money?

 

[asabay]

Perhaps try an "Italian tune up" before spending much money?

hi gordmac, what's an italion tune up ???

 

[julians]

hi gordmac, what's an italion tune up ???

Italian tuneup - Wikipedia.

 

[penfold]

Patent potions in bottles are unlikely to resolve whatever is causing the oil burning; that will need new valve guide seals if that's the problem or a rebore plus new rings and pistons(or maybe get away with a hone and new rings if you're lucky).

 

[gordmac]

hi gordmac, what's an italion tune up ???

Make the engine work hard for a while, run it at almost full rpm or even full rpm for a while. There is a theory, particularly for older engines, that running them at low load for long periods of time will glaze up bores and cause oil consumption. There is a chance running it hard might reverse the problem a bit.

 

[penfold]

It prevents it happening but will not reverse it if it has.

 

[QBhoy]

Hi. Mostly covered above. And could be a worn engine. But an optimist man, might check and try a few things first. I’d be asking or checking;
Is she running cold ? Cold running engines like this, that aren’t getting up to temperature for any reason (thermostat issues etc) will burn oil, because they aren’t at their designed optimum running conditions. Diesels rely on solely compression to ignite the fuel. Cold means tolerances aren’t right, contraction and poor compression.

Check the condition of the oil. If she’s got a sump full of thinned/diesel diluted oil…or even the wrong oil…then her compression will be lacking…again…burning oil.

Just something’s to ponder over, before going all in perhaps. Best of luck.