Sterndrive oil Change on 4-cyl GM Alpha One

andrewsilver

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May 2, 2001
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Wondering if anyone knows if I can change the engine oil by unscrewing a drain plug under the engine, instead of drawing the used oil up the dipstick tube.<br /><br />I have a 1990 Mercruiser 4 cylinder 3.0L GM with Alpha One sterndrive, and there seems to be a fair amount of space under the engine. <br /><br />So if there is a drain plug, I probably could get to it, if someone can tell me where it is. I don't want to buy a dipstick oil remover if I don't have to...<br /><br />Thanks!<br />Andrew
 

hoot

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Sep 8, 2002
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Re: Sterndrive oil Change on 4-cyl GM Alpha One

removing the plug is a preferred way, it gets sediment out of the pan and removes more of the old oil. i have never seen a pan without a plug, but maybe you have one. is there room for an oil catch pan and a path to remove the pan once it is full of oil? a sump full of oil is a nasty thing. i have used two heavy duty garbage bags inside one another to catch oil, must be careful removing bags so they don't tear and leak.
 

MFG197

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Aug 26, 2002
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Re: Sterndrive oil Change on 4-cyl GM Alpha One

if you do have a plug and get it out (or pump out the first time) get one of those hoses that threads into the pan and can be pushed out the drain hole of the boat to drain next time. if you don't want to buy a pump try and borrow one.
 

crazy charlie

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May 22, 2003
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Re: Sterndrive oil Change on 4-cyl GM Alpha One

Go for it!!!!! The oil pan must have a drail plug and if you can get ti it thats how I would change the oil.The other thing you must consider is how to get the oil out of what you drain it into.Charlie
 

Rhadley

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Jul 20, 2003
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Re: Sterndrive oil Change on 4-cyl GM Alpha One

I hold a funnel under the drain plug, with a tube attached to the funnel. The tubing runs out the bilge drain hole into an oil pan. Then I just open the drain plug far enough to control the flow into the funnel, down the hose, and into the pan outside the boat.
 

Bayrider

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Apr 4, 2004
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Re: Sterndrive oil Change on 4-cyl GM Alpha One

Andrew.Put your hand on the bottom of the sump well(lowest part of the sump)and move it towards the back.When you reach the back corner of the sump well you will find the plug about 1" up the back wall of the well.
 

andrewsilver

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May 2, 2001
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Re: Sterndrive oil Change on 4-cyl GM Alpha One

Holy moly! Bayrider - you are 100% right! The drainplug is right behind the sump, and it's in full view! There's so much room there to work, I think it'll be easier than changing my car oil!<br /><br />It seemed so simple - I didn't believe you at first. so I decided to open it just to check - and sure enough you were right.<br /><br />If you don't mind - I've got two more quick questions: <br /><br />1. How much oil does it hold (1990 Mercruiser 4-cylinder GM block). <br /><br />2. What viscosity do you recommend. I'm in Texas and ride all year round, summers are over 100. Last oil change was Aug02, I used Castrol Syntech (fully synthetic) 10W40.<br /><br />Thanks to all for your advice. Much appreciated.<br />/Andrew
 

Bayrider

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Apr 4, 2004
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Re: Sterndrive oil Change on 4-cyl GM Alpha One

Hi Andrew.It will take 4 US Qts (3.8L).I use a 15W40 HD/Diesel oil and it works very well in my 3.0L 135HP ALPHA 1 GEN 2 . Over here in N.Ireland we are lucky to get 80 of heat so my oil works OK.If the Castrol syntech works for you then keep using it.I would suggest you change the outdrive gear oil as well.One last thing Andrew,I would change the oils at the end of each season along with a full service, plugs etc.and remember don,t over fill the sump. Regards Raymond. ;)
 

MFG197

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Aug 26, 2002
Messages
236
Re: Sterndrive oil Change on 4-cyl GM Alpha One

good luck with that funnel idea, I could just see the oil coming out faster than it will go down the tube...big mess. but then again I have never tried that.
 

andrewsilver

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Joined
May 2, 2001
Messages
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Re: Sterndrive oil Change on 4-cyl GM Alpha One

Thanks Raymond, much appreciated. Just curious - where abouts in Ireland do you ride your boat? I trust not on the River Liffey... ;)
 
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