I have a 2004 250 XS that everytime I check the engine oil tank , it is approx 3/4 inch low. All my caps are tight and there are no apparent leaks anywhere. What exactly should I be replacing or checking? It has only once gotten low enough that I got the four beeps, but ever since then I check it every outing and it always needs topping up...
does your onboard fill from the top or the side ?
From what I understand the ones that fill from the side will not fill over the oil line intake. If they do they will bleed back down as the tank will eventually loose pressure.
But Im sure Don will be on here t o advise,
If you have ABSOLUTELY no leaks (this can be confirmed by disconnecting the hose from the crankcase pressure fitting, and performing a pressure test on the hose):
I would recommend that you replace BOTH the crankcase pressure fitting (Starboard front lower end of the crankcase), and the 90 degree check valve fitting just below the oil tank itself.
Your engine mounted oil tank should remain FULL TO THE BRIM at all times.
Our parts department should have both fittings on hand.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
So by the sounds of things there is a check valve that doesnt allow the oil to return to the boat mounted tank ?
I have a 2002 300X and was told by a reliable source that when the line enters from the side of the motor mounted reservoir that the oil level would not go above that inlet as once the pressure is eventually lost in the tank it will drain back.
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by onttr22 »</td></tr><tr><td class="quote">So by the sounds of things there is a check valve that doesnt allow the oil to return to the boat mounted tank ?
I have a 2002 300X and was told by a reliable source that when the line enters from the side of the motor mounted reservoir that the oil level would not go above that inlet as once the pressure is eventually lost in the tank it will drain back.
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Incorrect. The engine mounted tank should ALWAYS remain COMPLETELY full.
Disappearing or siphoning back oil level is an indication of a leak in the system, OR a faulty/leaking check valve.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Check valve part number ?
"Tee" check valve: 42425 4 (the usual culprit)
If you want the pressure check valve for the crankcase: 878105 1
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by EuropeanAM »</td></tr><tr><td class="quote">If you have ABSOLUTELY no leaks (this can be confirmed by disconnecting the hose from the crankcase pressure fitting, and performing a pressure test on the hose):
I would recommend that you replace BOTH the crankcase pressure fitting (Starboard front lower end of the crankcase), and the 90 degree check valve fitting just below the oil tank itself.
Your engine mounted oil tank should remain FULL TO THE BRIM at all times.
Our parts department should have both fittings on hand.
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i had the same issue.don recommended these parts and i got them from him and it fixed my problem!!!
Should this be filled to the top even when the engine is not running? Is there an alarm if it is not filled properly?
It should always be completely full... There will be four short beeps with steady intervals...
Thanks. I'll take a look next time my cowl is off. No beeps or anything; just curious and learning something new everyday!
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by EuropeanAM »</td></tr><tr><td class="quote">"Tee" check valve: 42425 4 (the usual culprit)
If you want the pressure check valve for the crankcase: 878105 1
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I had the same issue with mine...I got the "Tee" check valve from Don and have no problem anymore.Thanks Don!!!
"Give a man a fish and feed him for a day...teach a man to fish and, he'll lay out of work, miss dinner dates with the wife....and live happily ever after"
"He, who dies with the most toys, wins"
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