since Volvo are willing to replace the engine it is possible they know something we don't. Other engines may have problems they are not revealing. I would be reluctant to drag out the process in case they change their mind.
I guess I'm a little unclear on what the actual situation is.
Has Volvo said they will replace the engine covering all parts, material, and labor?
During this 50 hours do not baby the engine. Run it like it was designed so that oil usage can be accurately noted. A newer 4 stroke will consume about 0.03% to 0.05% oil per amount of fuel.
Has Volvo told you in writing the design oil burn rate for that specific engine?
Did you have the engines surveyed and fluids analyzed when you bought this boat? Nice benchmark to have for comparison. If not I would pull samples for oil and coolant now and have them analyzed. The Volvo dealer should be able to do a proper survey but if it was me I might be inclined to contact a third party independent maybe from up to 100 miles away.
For the record your burn rate doesn't sound that out of spec as my Luggers with 4700 hours burn roughly .0025 per unit of fuel. Your two engines are running: 7/(65*128)=.00084 and 24/8320=.0028 per unit of fuel. I'd pay a little more attention to the tight engine at this stage. Run them hard and hot at various speeds over the next 20 hours. And then pull samples again.
Via iPhone.
They ran oil samples in the fall, around 50 hours ago. I'll have them take new ones and compare.
Why coolant samples?
Thanks for your help.
RickB,
Volvo has committed to replacing the long-block, and will keep the case open until 3/31/16.
If at that time it's clear that the engine needs replacing - they'll do it.
I just love how we have dozens of threads on this forum blasting Volvo for no support and then we are treated to this hot mess.
This oil burn rate is interesting and I'll see what Volvo says what my range should be.
Do you mean .4%? Because .04% equates to .0004, which is minuscule.
65 x 128 x .0004=3.328 oz, right? But 65 x 128 x .004= 33.28 oz.
The first calculation seems low and the second seems high.
It appears you are back on the hunt here. What does an oil analysis have to do with above spec oil consumption?
Your reported high (what is it again?) oil consumption triggered alarms, it should. Volvo has published oil burn rates, yours are in exceedance from the get go.
FYI, minuscule oil burn (not drops and leaks) is indeed the reality for modern era diesels. This summer my 12 year old 2000 hour engines are around 0.07% with drips accounting for a goodly amount.