Smoke on Start Up

[Orion C&C 33]

I'm back again to seek advice from the Afourian group...

All summer after the fixes the my Atomic 4 was up and running.. with no further issues till now.

All of a sudden on start up it's been bellowing smoke, not grey smoke or anything darker, but just white smoke and only for a minute or so on start up then it clears up.

I've checked the spark plugs they're all dry and not fouled or wet in any way and on inspection down the spark plug hole nothing seems wet.

I run down to the marina every 2 weeks or so to start up the motor to keep things turned over and have the engine run for 15 - 20 mins or so... You can see the orange tinge of colour close to the exhaust outlet in the photo.

Is the more due to:

1/ Head gasket gone.

2/ Exhaust manifold

3/ Heat exchanger.

The exhaust water has a tinge of orange colour similar to my antifreeze and the reservoir well drains about half a quart after some time... I don't know at what rate since this is something new.

Anyone have any ideas?

[Mo]

If there is antifreeze in it you might smell the antifreeze. If not, well the loss is very minor and not likely the cause of the white smoke.

Here's something that does happen in spring and fall. The actual exhaust air is warmer than the ambient air temp outside. At this time of year it's not uncommon to see a white smoke, especially in the morning where the ambient air temp is cooler. You might have a combination of both going on as well.

The coloring of the exhaust, after sitting two weeks, is not uncommon. Water is sitting in the exhaust system, there's a bit always sitting there somewhere and it does get discolored. If it clears in less than a minute that would be normal. I'm raw water cooled and if the boat has been sitting the exhaust will look dirty initially.

I'd just keep an eye on the reservoir for now, take a book and monitor the hours used and if you have to add antifreeze. Watch the temp gauge closely as well and see if you are heating up under load.

[ndutton]

Is it smoke or steam? It makes a big difference in chasing it down.

[Orion C&C 33]

If there is antifreeze in it you might smell the antifreeze. If not, well the loss is very minor and not likely the cause of the white smoke.

Here's something that does happen in spring and fall. The actual exhaust air is warmer than the ambient air temp outside. At this time of year it's not uncommon to see a white smoke, especially in the morning where the ambient air temp is cooler. You might have a combination of both going on as well.

The coloring of the exhaust, after sitting two weeks, is not uncommon. Water is sitting in the exhaust system, there's a bit always sitting there somewhere and it does get discolored. If it clears in less than a minute that would be normal. I'm raw water cooled and if the boat has been sitting the exhaust will look dirty initially.

Hi Moe...

The smoke is more like steam it dissipates in the air fairly quickly... It just started when the weather is still warm and the midday start up by the time I get to Pt Roberts shouldn't really cause a big billowing cloud. It's more like steam, I read somewhere on this forum that this may be the case with a leaking exhaust manifold or worse yet a head gasket that has failed.

I don't mind replacing the head gasket since it's easy enough to do. There is a tell tale sign that it has gone as shown in my next photo. One can see the blackened area where the exhaust has stained the head and block from escaping gases.

What do you think?

[Orion C&C 33]

Is it smoke or steam? It makes a big difference in chasing it down.

Hi Neil...

Nice to hear from you again... It's definitely more like steam.
I just posted a response to Moe with a picture of my head and block.

Showing staining from escaped gases...

In the end I don't mind doing a winter re-build on the head gasket and exhaust manifold if these are the two main sources that may be causing this bellowing smoke on start up.

Any thoughts you may have would be appreciated.

Cheers
Mel

[ndutton]

A cooling system pressure test is indicated - - before taking anything apart.

[Mo]

I agree with Neil. Generally if there is a leak into the combustion chamber from either a head gasket or the exhaust manifold you should find a plug or two that may look very clean. When I say "clean" it may not have any carbon on the plug anywhere as it may be literally steam cleaned during combustion. If enough water is getting into the combustion chamber a miss may develop. Also, check for signs of moisture on your dipstick.

[Orion C&C 33]

I agree with Neil. Generally if there is a leak into the combustion chamber from either a head gasket or the exhaust manifold you should find a plug or two that may look very clean. When I say "clean" it may not have any carbon on the plug anywhere as it may be literally steam cleaned during combustion. If enough water is getting into the combustion chamber a miss may develop. Also, check for signs of moisture on your dipstick.

There is no moister in the oil (no creamy colour or is the stick showing any signs )
Took the gear case cover off and no moister in there either..

The engine starts up with no hesitation or miss.. and it doesn't struggle to continue to run once it turns over...

Today when I was down I turned it over and there was very little smoke.. Not like it is when it has sat for a while.

I do a test on the cooling system once I find a kit to do so...

FYI I checked the plugs yesterday before start up since I already know it was going to bellow out this steamy smoke.

I'm have an idea where to start now... I'll follow up in the next week or so.

Cheers everyone.