White, Grey or Blue Smoke? Opinions wanted!!!

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Airstream345

Airstream345

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Joined
Jul 3, 2017
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FORTITUDE
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Kadey Krogen 54-8
Today after replacing the Racor filters I started each engine (FL 120's, 1150 hours each) to make sure the engines were properly primed. Both start right away and run well, and did again today. On start there is a lot of smoke and oil which doesn't clear up at idle in the marina.

OK, so I've read a million articles about diesel smoke already and while we're just off a fresh survey I can't help but be bothered by the amount of smoke and "slick" I get from our engines on cold start up.

After all we live in the PNW so oil slicks and smoky boats gather a lot of attention. I also want to make sure I'm treating these very old but very low hour engines well.

Here is what the port engine looks like on cold start:


My question is...dose this smoke look white, blue or grey to you. What should be an otherwise easy question for me turned hard today. I don't know if it was the overcast rainy day, the color of the water behind it or perhaps my skeptical, worst-case-scenario nature but at times it looked like all three to me!

I'd say I smell a strong diesel smell initially followed by an "exhaust" smell after a few minutes. Each engine was run independently and only at the dock. Temps only got up to 120 (as measured by my gauges and an infrared thermometer).
 
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Normal for Lehman 120s to smoke and leave a diesel sheen till above 150 degrees or so...maybe a bit higher ....
 
Engine is cold. What you are seeing is raw fuel and partially burned fuel. (White smoke) When warm it will disappear. All good.
 
Last edited:
Easting said:
Engine is cold. What you are seeing is raw fuel and partially burned fuel. (White smoke) When warm it will disappear. All good.
Click to expand...

X2
About the only thing you could do about it is have the injectors rebuilt and sometimes that won't clean it up.
Any idea how long ago any work on injectors?
 
Lehmans always mark their territory! The old technology engines are efficient at one fairly narrow speed range and one similarly narrow temperature range. Don't start them until you are ready to leave, throw off the lines and warm them up with a load and they will smoke for a shorter time and there will be less fuel in the water (another advantage is that if somebody takes umbrage at the sheen, you will be gone!). Comfort yourself knowing that most of the fuel will evaporate and the smoke will stop........shortly.

Injectors should be done at the proper intervals, see the Lehman manual. However, don't expect a huge change, you will get better "mileage" with serviced injectors but as she already starts well, little else will change (she "might" run smoother).

The Lehman is very reliable in a boat, make sure you burp the coolant as per the manual, you probably want to change the lift pump gasket as they leak, check the injector fasteners both on the outside of the block and under the valve cover, do the American Diesel catch-can mod and the Simms pump mod (change the oil in it at 50 hours and monitor) and make sure to not put too much oil in it (the dipstick was calibrated for a truck, yours are now tilted quite a bit). That's all I can think of before dinner.

There is a mod for the fuel filters on the engine too, recommended.
 
Looks just like my Perkins on cold start. My engine runs good, sounds good, and doesn't use oil between changes. I'm not concerned with the smoke.
 
Cold engine with slack in the clearances allow oil to drop down the valve guides and pistons pick up oil with pistons slack against the cylinder walls. This causes blue smoke on start up. White smoke should not really be involved on a startup. rather it indicates a cooling leak, head gasket, cracked head/block allowing water into the exhaust.
Dark gray or more black, over fueling, injector pump issue or injectors. Surprised these three observations were not first out of the box, while the ones given do fit the OP's questions, just seem to lack a bit.
Good discussion subject, trust others will jump in.

Al-Ketchikan
 
I wonder how effective Wolverine oil pan heaters would be on Lehman and Perkins etc. diesels. These are almost miraculous on Cummins B-Series at minimizing white smoke during cold starts. They are highly recommended by Tony Athens and other Cummins pro's as well as many other operators of diesel engines and powerplants.

After I installed them, I was able to completely remove the factory air heaters and they start instantly.
 
“White smoke should not really be involved on a startup.”

Strongly disagree. Most all diesels especially older mechanicals will throw white smoke ie un burned fuel when cold. White smoke can also be attributed to other issues but doesn’t normally go away after engine warms if it is do to mechanical failure. That Lehman is pouring fuel into those cylinders when it it first starts. All of that fuel is not going to burn until engine warms to designed operating temp.
 
Xsbank said:
Lehmans always mark their territory! The old technology engines are efficient....That's all I can think of before dinner...
Click to expand...
Add to this useful free-ranging advice the American Diesel upgraded raw water pumps, which overcome the drive connection breaking with instant loss of raw water supply.
 
Al, from what I've read/learned (admittedly I'm currently inexperienced with diesels and marine diesels in particular) white smoke on startup indicates unburned diesel fuel - and yes, possibly, coolant. Given I'm not losing coolant and see no other signs of a head gasket failure (coolant in the oil, oil in the coolant, hard starts, etc) I'm thinking this combined with the strong diesel smell on startup equals normal cold FL startup - which chills me out a bit.

My original question was more about what color others think this smoke is. My observations became untrustworthy and I suspect that little voice in my head was saying "it could be blue, no grey, no blue...but it's probably just white".

I can get over it as "normal" as again, a strong engine survey indicated nothing wrong except a list of updates needed (Xsbank's list covered many of them) but on a cold rainy PNW day it's easy to see things in the smoke I guess. ;)
 
Last week as part of my annual maintenance schedule, I removed the air filters
and cleaned them. Soaked them in a bucket of hot water with Dawn dish soap and also used some simple green.

It made a huge difference on how much un-burned fuel was coming out the exhaust. Soaked them in a bucket of hot water with Dawn dish soap and also used some simple green.

I'm thinking that maybe the dirty filters was from all the ash in the air this year from the forest fires.
 
Appears about the same as my 120 cold starts here in warm S. California.
 
Don't panic and keep it simple.
These old engines WILL smoke on start up AND leave an oil sheen.
They are NOT computer controlled and need to be at working temperature to burn all the injected fuel.
Basically your engine is not hot enough to be efficient, I bet you don't run a marathon immediately jumping out of your pit either.

The answer, when you wish to leave the marina keep a bottle of dishwasher liquid handy. Start your engines, be ready to cast off your lines, get your crew to check for 'oil sheen' and give a generous squirt of washing up liquid onto the sheen, this will unlock the surface tension molecules and disperse the sheen.
Now cast off and load your engines lightly whilst leaving the marina, when and ONLY when, you can open the throttle gradually, WATCH YOUR WASH, and slowly load the engines until they run at normal operating temps.

I'm visiting Miami at the moment and have been observing the marine antics at various marina's as I mooch around, and I find the lack of manners to fellow mariner neighbours regarding excess boat wash in confined area's with extremely loud radio/dvd noise is very selfish and rude.
That type of behaviour in our boating region may well to a discussion on your educational achievements and parentage, in some cases lead to a visit to your dentist.


IT COSTS NOTHING TO BE NICE TO YOUR NEIGHBOURS and you'll earn their respect.

As an aside, many marine engines do not have a paper element air filter just a simple wire net gauze.
I fitted one , it's surprising how dirty the air is in your engine room, it also cuts down the engine intake noise as an added benefit.
I wash mine once at the end of the season and replace it every other season. Clean air, clean fuel, clean oil and your engine will outlive you.
 
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Irish Rambler said:
Don't panic and keep it simple.
These old engines WILL smoke on start up AND leave an oil sheen.
They are NOT computer controlled and need to be at working temperature to burn all the injected fuel.
Basically your engine is not hot enough to be efficient, I bet you don't run a marathon immediately jumping out of your pit either.

The answer, when you wish to leave the marina keep a bottle of dishwasher liquid handy. Start your engines, be ready to cast off your lines, get your crew to check for 'oil sheen' and give a generous squirt of washing up liquid onto the sheen, this will unlock the surface tension molecules and disperse the sheen.
Now cast off and load your engines lightly whilst leaving the marina, when and ONLY when, you can open the throttle gradually, WATCH YOUR WASH, and slowly load the engines until they run at normal operating temps.

I'm visiting Miami at the moment and have been observing the marine antics at various marina's as I mooch around, and I find the lack of manners to fellow mariner neighbours regarding excess boat wash in confined area's with extremely loud radio/dvd noise is very selfish and rude.
That type of behaviour in our boating region may well to a discussion on your educational achievements and parentage, in some cases lead to a visit to your dentist.


IT COSTS NOTHING TO BE NICE TO YOUR NEIGHBOURS and you'll earn their respect.

As an aside, many marine engines do not have a paper element air filter just a simple wire net gauze.
I fitted one , it's surprising how dirty the air is in your engine room, it also cuts down the engine intake noise as an added benefit.
I wash mine once at the end of the season and replace it every other season. Clean air, clean fuel, clean oil and your engine will outlive you.
Click to expand...

I bet we could find a simple way to inject the dish detergent into the wet exhaust just ahead of the thru hull transom port.
 
Smoke? My 2011 JD 4045 hasn't ever. No smoke is good.
 
Irish Rambler said:
extremely loud radio/dvd noise is very selfish and rude.
That type of behaviour in our boating region may well to a discussion on your educational achievements and parentage, in some cases lead to a visit to your dentist.

IT COSTS NOTHING TO BE NICE TO YOUR NEIGHBOURS and you'll earn their respect.
Click to expand...

I totally agree with the extremely loud radio etc. For that reason I have not installed external speakers. I think some folks are deaf. I suspect there is a volume control for the outside speakers but maybe the do not know where to find it.
 
With the white smoke problem: First check your coolant usage. Should be none.

Excessive sheen, a sticky injector ?.... Might be time to consider having them rebuilt and pop tested.

As always, I recommend getting a good tech out there to get his opinion and recommendations. If nothing else, it will be a learning experience and save you troubles in the future.
 
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alormaria said:
I think you should just run them for the year before changing anything.
Click to expand...


Agreed, when I bought my boat in 2014 the mechanical inspection recommended replacing the injectors asap (Lehman 120) due to 2,300 hrs. I had them replaced, no significant difference in smoke or oil sheen. Run it for a while as is.
 
I love this advice. Over the years I've learned not to be too hasty with changes and improvements.
 
Be careful with the dish detergent, in many places in the US (if not all) using it to disperse a sheen is illegal.

There are legal dispersants thpugh from what I am told.
 
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If is really a problem for your neighbors or if they think you are fogging for mosquitos every time you start-up, you could install block heaters.
 
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