correct oil weight

[andrewterri]

My boat is a Monterey 196 with a 4.3 mpi ect mercruiser.(2A176701). My problem is the boat had an oil change before I got it and was told the dealer did it but there is no marking on what brand and weight was used.. There is a mercruiser oil filter on it so I figured he is telling me the truth and the dealer would likely use mercruiser/quicksilver oil. so now I am trying to figure out what weight to add. the boat has used a normal about of oil and it is still show 1/4 on the dip stick. I want to add more since it is getting low and the boat is in the water so not sure how perfectly level the boat is when checking. oil pressure is great so its not to low. I know some of the older mercruiser's used 25w-40 but not sure if my engine does. I can not find the weight stamped anywhere. What weight should I get and add to it? Would mixing lighter weight with a heavier weight of the same brand hurt? Thank you in advance.

 

[Bondo]

I know some of the older mercruiser's used 25w-40 but

Ayuh,...... Whether the dealer used this or not, You usin' it won't hurt a thing,.....

 

[andrewterri]

Awesome, thank you bondo. I will pick some up and throw it in.

 

[achris]

... and the dealer would likely use mercruiser/quicksilver oil.....

Very UNLIKELY... Marinas tend to use a lot of oil, so they'll be buying it in 205L drums, and definitely not from Merc (too expensive!). Likely a Shell or Gulf Western or.....

Use whatever oil you like, just follow the advice in the Owner's Handbook (you know, the one everyone throws away, still in the wrapping ) on weight and 'S' specification.

Chris........

 

[andrewterri]

That's my problem achris, I don't have one from mercruiser only from Monterey which does not cover the engine. I ordered one that never came after nearly two months waiting, just thinking mercruiser was taking forever, I found out the order was cancelled because my card zip code did not match my address since we just moved. Need to order another but at 90 dollars im trying to make it fit when everyone needs school clothes at once :facepalm: I was hoping one of your guys knew off the top of your head what they called for.

 

[achris]

$90 for an owners handbook? OUCH! Are you sure that's not for the SERVICE manual?


As a guide, I use Delvac 15W-40, same as I use in my Landcruiser with a GM 6.5L Turbo diesel... I figure if it can take the stress of me and that 6.5 engine, it's just fine in the boat engine.

Here's what the owners guide says.

 

[andrewterri]

Thank you achris. Yes, that is the service manual price I need to know how to drain the engine for winterizing and where the plugs are at. I am surprised in the manual page you posted for me it says not to use synthetics. Again, thank you very much that really helps as I have been looking for that.

 

[achris]

The Owner's Handbook also contains winterizing information. Except, we do not refill the system with AF, air don't freeze! Well, actually, it does. But at that temperature, the last thing you'll be worrying about is the boat!

 

[andrewterri]

ya if we hit absolute zero we all have bigger problems.

 

[Scott Danforth]

I use shell rotella T4 15W-40 because its $11 a gallon

 

[andrewterri]

I just got off the phone with mercury/mercruiser. They gave me great information and helped me get the correct owners manual ordered. It was only 30 dollars shipped. They advised 25w40 synthetic blend and to fully seat the dip stick when checking. I guess that is their newest recommendation on oil. Thank you guys for all your help.

 

[andrewterri]

Scott, do you happen to know if that Rotella is catalyst compatible?