Mercruiser 4.3L Alpha Oil Change

monkey710

Cadet
Joined
Jun 11, 2007
Messages
6
I was trying to change the oil on my Mercruiser 4.3L Alpha today for the first time. The engine has the installed drain apparatus and was all set until I went to loosen the oil filter to vent the system. I cannot find the oil filter. The manual is of no help.

Can someone please describe to me where it is located? The only place I couldn't look is all the way aft near the transom and if that is the case, how do I get to it?

Thanks in advance
 

WAVENBYE2

Lieutenant Commander
Joined
Apr 28, 2007
Messages
1,636
Re: Mercruiser 4.3L Alpha Oil Change

I have a 97' block 4.3L Alpha , mine is located on the port side right below the manifold toward the back of the block on port side.What year is it???
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: Mercruiser 4.3L Alpha Oil Change

Location depends on year, carbed or efi, and/or if the previous owner did something wierd with the location.
Also, were you trying to change the oil on your Alpha or the engine?
 

monkey710

Cadet
Joined
Jun 11, 2007
Messages
6
Re: Mercruiser 4.3L Alpha Oil Change

I have a 97' block 4.3L Alpha , mine is located on the port side right below the manifold toward the back of the block on port side.What year is it???

Thanks I found it, now just having a hard time finding the replacement part and a wrench that will fit.
 

Liquid_force

Petty Officer 1st Class
Joined
May 7, 2003
Messages
318
Re: Mercruiser 4.3L Alpha Oil Change

If you need a wrench someone put it on too tight.
The 1st oil change after we bought our boat someone had CRANKED the filter on -- we had to drive a screwdriver through it to remove it. No probs in 4 changes since then. Never needed a wrench.

Unless it's a remote mount weird size filter get a Supertech 3980 :)
Good filters - about $2.50 IIRC
 

WAVENBYE2

Lieutenant Commander
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Apr 28, 2007
Messages
1,636
Re: Mercruiser 4.3L Alpha Oil Change

I had very little room to get the standard oil wrench on there, I bought the type that slips on the bottom using a 3/8 ratchet, can you see what is written on the filter? If so tell the person at the auto store what it is and he should give you the right one for it. I agree with Liquid-Force if all else fails pound in a screw driver through the side and loosen it that way, as far over to the right that you can pound it in straight and pull to the left should get it by hand the rest of the way, BE WARNED make sure you have some thing underneath to to catch any oil that might spill.
 

fourwinnsdook

Petty Officer 2nd Class
Joined
Jun 12, 2007
Messages
176
Re: Mercruiser 4.3L Alpha Oil Change

just got my boat, changed the oil, and some dumb *** had the oil filter cranked on. even after i put the screw driver through it and turned it 1/4 turn it was still to tight to get off by hand. Mine's an 86, and it's under the manifold as well. I bought a marine oil filter from a boat store because my dad told me to only use a marine oil filter is this true? Is there a difference? The one i bought didn't fit so i had to go to wal-mart and look up the filter for an 86 astro van with a 4.3L, It worked perfect.:D
 

Liquid_force

Petty Officer 1st Class
Joined
May 7, 2003
Messages
318
Re: Mercruiser 4.3L Alpha Oil Change

from what I've read marine filters are SUPPOSED to be more of a "high-flow" filter, since a marine engine runs at high rpm's a lot of the time. Other than that I would think they're a little more resistive to corrosion.

The first filter I bought was a Sierra marine filter, but from then on it's been Super-tech. We wakeboard, not drag race - 2600-2800 is our typical rpm - I'm not worried about flow rates.
 

bayliner3

Recruit
Joined
Apr 27, 2008
Messages
2
Re: Mercruiser 4.3L Alpha Oil Change

I have a 2007 Byaliner 185 with the 4.3, i cannot find the filter to cahnge the oil...any help?????????
 

Antelope

Recruit
Joined
May 2, 2008
Messages
4
Re: Mercruiser 4.3L Alpha Oil Change

I think I may have a similar engine. It is a Yamaha engine with a Mercruiser outdrive. It's a 5.0L though. By the descriptions above it has a similar layout. The oil filter is in the bilge. As mentioned - port side basically at the stern, under the manifolds. Hard enough to see, let alone remove. Mine is at the cottage and I am at home sourcing parts for it to revive it for the summer. If anyone knows what oil filter I need to replace it, can you let me know. It will save me a whole extra week!

Thanks
 

BIGSTRIPER80

Seaman Apprentice
Joined
Jan 22, 2008
Messages
48
Re: Mercruiser 4.3L Alpha Oil Change

For the type of filter you are supposed to use is going to be some debate. Depends on how you feel about it. I have an 86 4.3 and it's a project right now and I have only been using automotive oil filters. Some guys will tell you to only use merc and merc oil.

I think if i had a nicer boat or a new boat I would probably use more expensive parts bust since mine is just to beat around in I go the cheaper route and I don't think it should be a problem. Just my 2 cents.

Andrew
 

Bondo

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Apr 17, 2002
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71,098
Re: Mercruiser 4.3L Alpha Oil Change

Ayuh,.......

You guys Do realize this thread is a Year Old,..??..??..??

On your motors,.... All of you,.. The oil filter, if mounted on the motor,+ Not remotely, is on the lower port aft corner of the Block, under the manifold.....

I run Napa Gold filters on My boats,.... They're actually rebadged Wix filters,+ Wix is 1 of the Best.......

There used to be a link to an in-depth study of Oil Filters floating around here, done by a Member, I think,......
If I remember correctly,... Hastings,+ Wix came out on top, and Purolator,+ Fram were on the Bottom...... The OEMs are just Rebadged somebodyelse's,+ came in the middle of the pack......
I don't have the link,.. But I'm pretty sure somebody might.....
 
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