Complete rebuild - mr1 still consumes oil

[wajetter]

Since purchasing the boat, I been dealing with oil consumption on both engines. Measured every which way - cold on trailer , on water hot, on water cold. Had to consistently add up to half a cup after each use, a mere 2 hours.
So, rebuilt both engines this spring:
- new WSM pistons and rings
- new chains
- new valves and their seals
- checked (plastigauge) crank and rod bearings and replaced crank bearings out of spec (a couple were too small). Rod bearings were all in spec.
- had ECUs repaired (apparently water damage had some injector issues)
- all cylinders measured 165-170 cold and throttle open.
To my dismay, seeing absolutely zero improvement in oil consumption.

What can be some other reason for oil consumption? Usual culprits were addressed: pistons and valve seals.

 

[tdonoughue]

Question: Is your exhaust blue? With that level of consumption, if it is getting into the pistons and burning, I would expect blue exhaust. If the exhaust is not blue, then I would begin to suspect a cooling system issue perhaps, where maybe oil is leaking into the cooling system (and then ask: any evidence of oil slicks when you are idling somewhere for a time?).

 

[Divouneh]

One question: what is the oil level on the deep stick ( medium/ high/ over the high level) ? It’s strange that both rebuild engines have the same “trouble”. It’s just an idea, I will watch the pressure in the casing, you could have the same wrong pipe with suction of oil/vapor… again it’s just an idea I am not an expert…

 

[Cobra Jet Steering LLC]

What does the air cleaner filter look like on M R 1 engines if you are overfilling the oil it will clog the filter as it is sucked into the air filter through the breather tube and if you are overfilling it unintentionally it will continue to get pulled into the air cleaner . Also when you check the oil level you need to place a small level on top of the engine and have the engine completely level plus always set the oil level 1/2 quart below the full line .

 

[wajetter]

I check the level cold on trailer, then again after a hot run in the water.

What does the air cleaner filter look like on M R 1 engines if you are overfilling the oil it will clog the filter as it is sucked into the air filter through the breather tube and if you are overfilling it unintentionally it will continue to get pulled into the air cleaner . Also when you check the oil level you need to place a small level on top of the engine and have the engine completely level plus always set the oil level 1/2 quart below the full line .

The air cleaners I have are new from WSM - they are not paper but rather a plastic or metal mesh. So they won’t clog. Nevertheless, they are clean. I popped the cover and ensure no fumes are present in intake area.

 

[wajetter]

I check the level

The air cleaners I have are new from WSM - they are not paper but rather a plastic or metal mesh. So they won’t clog. Nevertheless, they are clean. I popped the cover and ensure no fumes are present in intake area.

Should the level be placed on top of the intake cover ? It’s not exactly flat

 

[wajetter]

I haven’t seen this addressed. How long do I wait before checking level after a high speed run in the water, followed by a couple minutes idling in the water? Do I wait some time for oil to drain or check right away before it drains? Manual doesn’t specify unfortunately. If the oil drains too quick from the tank, it will always show low while the crankcase is full of oil. But, that would show up as overfilled.
Is checking oil with the fine running valid ?

 

[wajetter]

The oil got dark within a couple hours, here’s a comparison

 

[Cobra Jet Steering LLC]

Should the level be placed on top of the intake cover ? It’s not exactly flat

Go to a dollar general and get a 12 inch long plastic level , place it on a flat surface on top of the engine to see if the engine is level, when you check it , as for the oil only, replace what you removed and bring some oil when you go to the water so you can then run the engine in the water and check the level , I also bring a big plastic turkey baster with a hose on the end to remove any excess oil if necessary and leave it 1/2 quart below full . If the oil got that dirty that fast there was probably a lot of old oil still in the engine

 

[wajetter]

Go to a dollar general and get a 12 inch long plastic level , place it on a flat surface on top of the engine to see if the engine is level, when you check it , as for the oil only, replace what you removed and bring some oil when you go to the water so you can then run the engine in the water and check the level , I also bring a big plastic turkey baster with a hose on the end to remove any excess oil if necessary and leave it 1/2 quart below full . If the oil got that dirty that fast there was probably a lot of old oil still in the engine

Thank you. This is a completely rebuilt engine with all new oil, all 4.5 QTs. New pistons, rings, crank bearings (some were out of spec).
Isn’t measuring on water guarantees the engine is level and proper? I measured cold after dropping off at the lake. Observed below Low mark, so add a few ounces until it shows we Low mark. Then go cruising. Next day, repeat, measure cold and have to add.

 

[Neutron]

You dont check oil cold on a mr1, you run it get oil up to temp, shut off and check after turning off. If you wait too long it bleeds back to the oil pan. Your service manual should show proper procedure

 

[wajetter]

You dont check oil cold on a mr1, you run it get oil up to temp, shut off and check after turning off. If you wait too long it bleeds back to the oil pan. Your service manual should show proper procedure

I ensured the engine is leveled front to back and side to side. Checked before warming up, as instructed. Oil was barely on the tip of the dip stick. Manual mentions to add oil on cold if the dip stick doesn't reach it.
Idled on trailer for good 10 minutes. At some point, I can see little steam out of oil tank - meaning oil is hot enough, should have expanded. Shut down and checked immediately: Oil not on dip stick at all, but I can see inside the tank it is there, it just went down a millimeter.
This is opposite of what I am expecting - the level should rise when warmed up.
Added 12 oz and it was showing mid-way between the tip and Low mark. Idled for another 6 minutes on hose. Checked again - it showed half way between the tip and Low mark.

 

[wajetter]

Performed compression and leak-down tests on the Starboard engine (Port engine is removed due to bearing failure, see this thread).
* Compression on hot engine, throttle fully open):
#1: 170 psi
#2: 170 psi
#3: 168 psi
#4: 170 psi

* Leak down tests (I am aware that proper test is at 100 psi input, but posted lower inputs for comparison):
All 4 cylinders are identical:
100 psi: <5% loss
90 psi: ~10% loss
80 psi: ~20% loss
70 psi: ~30% loss

I listened where air is going. I could hear air out of intake port and out of oil tank. With exhaust pipes on, not possible to hear if there's any air out of exhaust.

 

[wajetter]

Using Yamalube now. What if I switch to a higher viscosity oil like the VR1 20-50? Just throwing it out there.
I’ve read online that in some cases higher viscosity oil leads to more consumption. So, go figure.