-
Oil tank not staying full
250 pro xs 2010 been at shop for two days. Oil tank on engine not staying full. They have ran compression test. Leak down test, and checked for leaks. They don't know what else to do.
-
They also checked reels. All good.
-
Pressure test the system.
Replace check valve.
-
I believe that the tank is fed via vacuum. Sounds like a vacuum issue may be occurring. Check the caps on the main oil tank in the boat to make sure they are not loose. Then they can go from there.
-
Not with Vacuum...The oil is pushed to the tank via PRESSURE.
-
Mercury 3L/4 Stroke/Verado Moderator
A knowledgeable tech can easily confirm if the system has any air leaks, and if the oil "can" feed to the engine mounted tank by pressurizing the pressure line with a gearcase pressure tester (6-9 psi max).
As Savage indicated- the Crankcase Pressure Check Valve is a likely suspect.
If the tech does not understand this- you might seriously consider finding another.
-
They checked check valve on exhaust. It screen was clean and could not blow into it crankcase. When they pull 10 psi on that line it push oil to engine. Was that too much Psi? Tech said compression was 135 on all cylinders. That seems high. He also stated that leak down test was about 10%. Thanks for your help. Next closes motor tech is long drive.
-
Mercury 3L/4 Stroke/Verado Moderator
135 is "not believable" for compression.
10% leakdown percentage indicates an engine that is heavily worn and in need of rebuild.
10 psi is high for the purposes of pressure testing the oil system. Important to utilize a "hand-pump device" that will hold the pressure steady after it is applied (not a constant flow from some compressed air source).
There must be NO air leaks in the lines, fittings, connections, caps, o-rings, etc.
JMHO... and I don't know "them" from Adam, but I don't believe the Compression, I don't believe the Leakdown, and that makes it pretty hard to have faith in the rest. 
-
-
I went by today and questioned them about compression test. They did it wrong, they didn't remove all plugs. They did it the old way that doesn't work for a optimax.
They stated, they found problem and had ordered parts. They ordered the hull fill kit from Mercury for $95. Leak was from lid on hull to lid on tank in boat. Seems like overkill to order whole kits but I want it right.
-
Mercury 3L/4 Stroke/Verado Moderator
Normally can get the individual components, but there's a point at which it's better to just order the kit (sometimes more cost effective).
On the compression test: Been in the trade north of 40 years and don't recall ever seeing an "old" method like that in any OEM manual. At least you know what's going on now, and why it was not accurate.
Reply With Quote