how to diagnose oil consumption? - Page 2
 

how to diagnose oil consumption?

Started by bevans6, December 15, 2009, 11:54:50 AM

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bevans6

I expect that I know that I will indeed pull the engine next spring when the thaw hits, and freshen it.  In the meantime, it's asleep for the winter.  I may just pull the intake off and check that it's not the blower seals and run it for a few miles to see what it's doing then. 

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

Len Silva

Brian,

You've been given a big clue here.  How easily does it start when the temps get below 40 degrees.  If it start easy, I would go with the overfill assumption before spending time and money on an overhaul.

Hand Made Gifts

Ignorance is only bliss to the ignorant.

bevans6

I understand the clue.  Not quite sure exactly how to interpret this, but it will start at 40 degrees with several - maybe 5 - 5 to 10 second rolls.  Below that it needs the block heater or a shot of ether.  above 40 degrees it can usually start without aids.  what does that mean to you?

the oil is coming out the exhaust pipe, it's not leaking to speak of.  It slobbers pretty good idling.  There is definitely oil in there not being burned at idle.  What does this tell you?  I'm kinda handicapped in that I have to work from theory, not experience  :)  In my experience, theory is trumped by experience every time...   ;D

added - it goes from full to fill on the dipstick in about the same time it goes from fill to almost off the stick.  In other words, it doesn't seem to stabilize at half-way between full and fill or anything.  If it was an over-fill issue, I would expect it to.  I'm a little handicapped also in that I can't really test it right now, and every time I have  checked it on my trip it hasn't been parked in the same spot or particularly level.

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

Len Silva

Brian

I am most certainly not an expert here, just cheap.  I would want to rule out the easy stuff first, and overfill is about as easy as it gets.

Your starting ability sounds marginal to me, but not real bad.  I would drop it to one gallon low and run it for a hard 200 miles before I did anything else.

Hand Made Gifts

Ignorance is only bliss to the ignorant.

Dreamscape

Make sure you let it sit for a while after stopping before checking it, like 30 minutes. It takes that long to drain down. I made the mistake when I first bought ours, added oil and it was already full. :-[

Paul
______________________________________________________

Our coach was originally owned by the Dixie Echoes.

wildbob24

Brian,

I sent you an email with a DD Service bulletin about troubleshooting high oil consumption. It's a .pdf file that was too large to attach to this message.

Just want to make sure it doesn't get lost in your spam folder.

If any one else would like to see it, let me know

Bob
P8M4905A-1308, 8V71 w/V730
Custom Coach Conversion
PD4106-2546, 8V71, 4sp
Greenville, GA

bevans6

Thank you very much for the bulletin.  It answers a few questions I had, and gives some good test info! 

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

wildbob24

Brian,

Glad you received it. Just be sure you're safe when doing these tests. No loose clothing; ear and eye protection are a must. You haven't heard loud until you run one with the intake housing off.

It's a good idea to remove the cooling fan belt, as well. You won't be running it long enough for temps to be a problem.

Bob
P8M4905A-1308, 8V71 w/V730
Custom Coach Conversion
PD4106-2546, 8V71, 4sp
Greenville, GA

bevans6

the cooling fan belt removal is an excellent idea!  I probably wouldn't have thought of that.  I confess I wouldn't have thought that it would run with the air box covers off, either. 

so my drill is going to be check the blower for excess leakage, pull the air box covers and look for scoring in the cylinders that might indicate rings or piston pin issues, and see what happens.  I think it's slobbering excessively too, so that could be either of the above.

Cheers, Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

wildbob24

Brian,

It probably won't run with all the air box covers off, but will if you only remove one at a time.

We don't usually remove the fan belt completely; just slack the tension, slip it off the crank pulley, and stuff up into the cooling fan compartment. Then you can move freely about the engine compartment.

Bob
P8M4905A-1308, 8V71 w/V730
Custom Coach Conversion
PD4106-2546, 8V71, 4sp
Greenville, GA