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White Smoke

M

mschwenz

Contributing Member
"I have 2001 3.0 carb mercruis

"I have 2001 3.0 carb mercruiser and everything seems to be running fine except alot of white smoke while im running it in the driveway. My question is could this be just normal, the white smoke comes a few minutes after startup and continues at any rpm except a few seconds after i bring her down. Engine temp runs about 160, Normal? Thanks alot guys"
 
Are you sure it is not steam?

Are you sure it is not steam? "A lot of white smoke" would not be norma. Neither would steam. White smoke it typically oil smoke.
 
"Well its white smoke and it d

"Well its white smoke and it doesnt seem like steam to me, Btw i just changed the oil and was very dirty, what would cause oil smoke?? Steam??"
 
"What would create steam? Over

"What would create steam? Overheating, Just changed thermostat, before that water poured out the engine while running muffs and after that water just sputters after 5 minutes or so when the temp gets up.. Smoke still looks too white to be steam too"
 
"burning oil makes black smoke

"burning oil makes black smoke
rich fuel makes blueish smoke
Hot exhast meeting cool air makes steam.
Antifreeze from cooling system makes clouds of white smoke.
If white smoke/steam is from cooling system, you are probably loosing coolant and pressure build up in the heat exchanger system..is so equiped"
 
?s bill. rich fuel makes black

?s bill. rich fuel makes black smoke
burning oil makes blueish smoke.
anyways MIKE does the smoke disapate into the air quickly or does it linger if it lingers its more than likely burning oil from somewhere
 
I am thinking the temp is high

I am thinking the temp is high also - you may want to check the temp rating for that model and see for sure....I have a 5.7 and the temp is around 140 - you can pick up a laser thermometer which is a useful tool - could be an improper thermostat or failing one. Just a thought!
 
"[b]"What would create ste

""What would create steam? "

Ayuh,.. Depending on the local Temp,+ relative Humidity,...
Pouring water into a Hot exhaust stream will naturally create a 'ell of a Steam cloud....

That said,...
When was the Impeller last Changed,..??"
 
"ok gotta answer lots of quest

"ok gotta answer lots of questions now, replaced thermostat, never replaced impeller due to less than 50 hours, local temp 40ish, anybody know what the temp is s'posed to be for a 2001 3.0 carb? smoke/steam disapates... just want to say thanks to all you guys too"
 
since you replied that the whi

since you replied that the white smoke disapates quickly im more apt to lean towords it being steam. smoke would take a few minutes to dissaper
 
So would a bad impeller cause

So would a bad impeller cause steam and should water pourin out of the exhaust or just sputtering out?
 
Should be sputtering out of pr

Should be sputtering out of prop at idle but coming out in steady stream from under the side of I/O at the transom. Speeded up to about 1500 rpm it should become fairly steady stream at prop too.
 
"[b]"never replaced impell

""never replaced impeller due to less than 50 hours,"

Ayuh,... Change it.... Hours really don't mean Squat...."
 
"Ok did a few more tests, took

"Ok did a few more tests, took the hose from the intake to the tstat housing off and guided into a bucket for about 10 seconds and water came out about what a garden hose makes without a nozzle. then took off the hose to the exhaust from t stat housing and at appx 150 degrees on the gauge and it came out a steady stream (filled a plastic cup in about 7 seconds) This is telling me that im getting water flow to the t stat housing and its leaving to the exhaust but im still getting lots of steam (doesnt seem like smoke because it fades quick, doesnt linger)

for some more details,
idles at abouto 145ish to 155ish (on the gauge), when I increase it to an slow to medium rev (tach dont work either) , it goes up to about 165-175, havnt seen it break 175 but im sure it would if it were in the water cruising...
On a different note there is a little less steam today but it is also ten degrees warmer...

What I really would like to know if anybody knows is how hot should this engine run, at idle, at cruise, WOP????"
 
""idles at abouto 145ish t

""idles at abouto 145ish to 155ish (on the gauge), when I increase it to an slow to medium rev (tach dont work either) , it goes up to about 165-175"

Put in a new impeller to start."
 
"Ordered a new impeller today

"Ordered a new impeller today and will put it on when it gets here. An interesting thought popped into my head after i wrapped up the boat tonight, theres only one belt on the motor which i would imagine controls the circulation pump.. I have noticed the belt may be a little loose just never got around to tighten it, would this cause water not to circulate around the engine after it pumps through the t'stat housing because i have alot of water being pushed up from the drive (as tested) and not alot leaving to the overboard. Just a thought though what you guys think"
 
"Ok its been about a week sinc

"Ok its been about a week since last posted but finally got a chance to check up on things and take it out on the bay. When I was out this is what i noticed... Idled bout around 150 degrees, but when shifting gears almost sounds like its going to stall for a second. Otherwise runs up on plane nice and had nice power...Here is where we had problems... after about 7 minutues out there cruising (155-165F) she bogged down and stalled. Took a minute to start it back up and had a tendency to stall out until i gave it enough power to push up on plane. After i ran it back to the ramp everything seemed fine, temp was still low(150-155F) , started quick, etc..

When i pulled out the plugs they were black?
I only know that this usually means she's running rich..

Right now Im not to sure what to do anybody know what I should do about the plugs besides replacing them which I will do tommorow?? Thanks guys"
 
if you know how check and adj

if you know how check and adjust carb/choke P.S what happend with the white smoke problem did you figure it out?
 
""... after about 7 minute

""... after about 7 minutes out there cruising (155-165F) she bogged down and stalled."

That has happened to me and it turned out the float was too high; meaning it stayed open too long. If that is what you find, replace the float. It just happens all of a sudden; don't know why. It could be heavy from water or maybe to many bumps on the back roads."
 
"OK turns out the ignition coi

"OK turns out the ignition coil prong was all gummed out as well as the wire so I went ahead and replaced all that, Also replaced spark plugs and got the new impeller on. Took it out on the bay and it ran fine.. same temperature range and did not bog down.

The only thing that concerns me is that there is still white smoke/Steam??

Should i just let it be and chalk it up to normal operation??"
 
"mike
You may want to read yo

"mike
You may want to read your plugs after a run if the temperature stays good, and see if one is showing signs of steam cleaning. If so you may have a cracked head or bad head gasket. What's the air temp where you're at when running.
Bert"
 
"Mike
Steam cleaning will sho

"Mike
Steam cleaning will show up as a much cleaner looking plug than the normal burn indicators on a plug. ie no carbon, soot, oil, etc.
Bert"
 
"OK so if i understand this co

"OK so if i understand this correctely, cracked head/gasket leads to water in the cylinder turning to steam which leads to steam being pushed out exhaust??

Now here is my question when i disconnected the hose from the manifold coming from the t stat housing to check for water flow out of the t stat i noticed that the steam had gone away while i ceased water from entering the manifold???? which would now leave me to believe that the steam isnt coming from the cylinders because if it was i would still see steam coming out the transom right??"
 
By removing the colder water f

By removing the colder water from the manifold exhaust "fireball" of several hundred degrees there won't be any steam. Check the plugs as the Bt Dr said. No steam cleaned plugs? Perform compression test; if it is good then all is well. Forget about it.
 
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