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Random Quote: If I wanted your opinion I would have given it to you
have a 671 turbo blowing alot of white smoke not black not blue just alot of white smoke took the valve cover off valves look ok took turbo no oil in the turbo. did a compression testone cylinder down to 200 psi . Now my question is I took the little inspection port off and noticed that there was only two cylinder rings. Has anyone ever heard of this and and would the one bad cylinder be causing all the white smoke any help would be great
Bad cylinders can lead to unburned diesel what is ejected as white smoke, but so can steam which can be created by partially blocked water injectors on the exhaust risers or from corrosion build-up within the riser.
You really need to do a compression check, look for at least 330-350psi and also get your injectors checked. Did you notice a vibration while you were running, sort of like the prop being slightly out of balace. This could be a misfire under load that is the result of a low cylinder and/or failing injector.
Don't know much about the 671, but my general understanding is that excessive white smoke is an indicator of water entering the combustion somehow. Is your engine fresh water or raw water cooled? If fresh, are you topping off the reservior occasinally (better go check its level)? If so, you may have a leaking head gasket (hopefully) or a cracked head or cylinder wall (hopefully not). It's likely not a ring problem as the smoke would be mostly blue, indicating oil seeping past the rings or valves.
If your engine is of the "older generation" ie pre mid 90s, then it is not unusual to see white vapor on startup and a lesser amount that is continuous but dissipates during normal operation.
Hey, thanks. One of those rare moments when my mind actually coughed up something that may make sense.
A two ring setup is not out of the question. The top ring alone is principally the compression ring. You may also have a third ring at the very bottom - apart from the two near the top of the piston - that's not visible.
go over to boatdiesel.com, they will help you. Check your manual for the min compression (warm and cold) - I am almost positive that your number is way off the charts on the low side....
Very common, time for a rebuild, thankfully with that old gal it can be done in place. Out of curiosity, how many hours and what model.
671TI or 671 TIB, 1800 hours??
Oh Boy.
I have a friend with a pair of 6-71 TIB's that forked over a bunch of $$ for an overhaul 2 1/2 years ago. Back in May, he noticed the exact same symptoms you did, especially the loss of compression on one cylinder.
Here's the bottom line on the 6-71's. Air comes up from the exhausts back into the engine, causing corrosion in any cylinder having an air valve open.
I spoke at great length with the mechanic about this, and he proved his point by pulling the head off the good engine and replacing it with a fresh rebuilt one. Ran the engine up to temp, and shut it down. Overhauled the bad engine, and when it was finished, pulled the "fresh" head off the "good" engine. It was loaded with rust. Elapsed time, 9 days.
The mechanic stated (and showed me in writing) that he had recommended flaps over the exhausts as well as a complete reworking of the exhaust system at the time of the original rebuild to keep the backflow of saltair to a minimum, my friend did not heed his advice.
$20,000.00 mistake.
By any chance, is your 6-71 one of two in a Viking?
question for the deisel guys!
