How much oil does a Universal M25 diesel need

May 7, 2011
222
Catalina 30 Lake Lanier
I have a 1985 Catalina 30 with a Universal M25 diesel inboard. The engine manual does not say how much oil it needs, and it desperately needs a change.

Does anyone know, and are there any 'Gotchas!' I need to be aware of when changing the oil and the filter?

Is the 'Filter Removal Tool' the manual speaks of the typical one used on cars? (The strap that locks around the filter housing.)

This is my first inboard and first diesel...

Thanks!
 
Feb 8, 2014
1,300
Columbia 36 Muskegon
Capacity should be 4.3 quarts. It's the same filter used in many cars, so, same filter wrench.
Shell Rotella 15w 40 and Fram Ph 3593 filter is what I use. AutoZone or WalMart are the cheapest I've found.
 
Feb 26, 2004
22,986
Catalina 34 224 Maple Bay, BC, Canada
Some of the filters used on M25s are smaller than automotive filters, so buy the right strap wrench, they come in at least two sizes. Some oil will always be left in, so before you refill with 4.3 qts. put in "some", let it settle and use the dipstick. The dipstick has a seal on it. To check the oil, remove it part way, let it sit for a moment, reinsert and then check the level.

This is more info for you:

Engines 101 - The BIGGEST & BEST collection of M25 Series Universal Engine Information on the Internet, plus some M35, too :)

http://www.c34.org/wiki/index.php?title=Diesel_Engine

Critical Upgrades http://c34.org/bbs/index.php/topic,5078.0.html
 
Aug 2, 2005
1,155
Pearson 33-2 & Typhoon 18 Seneca Lake
Unless you have room to work at a drain plug under the engine (if there is one on your engine) you will need to suck out the oil through the hole where the dipstick is inserted. Electric model pumps for that purpose are available, but I have found those to be short lived and the tubes leak at the connections. Of course, being frugal (or thrifty, or just plain cheap) I opted for the least expensive model. The brass barreled, hand operated pumps are slow and give your forearms a good workout. However, so far I have found them to work best.
 
Jun 11, 2004
1,734
Oday 31 Redondo Beach
I have a 1985 Catalina 30 with a Universal M25 diesel inboard. The engine manual does not say how much oil it needs, and it desperately needs a change.

Does anyone know, and are there any 'Gotchas!' I need to be aware of when changing the oil and the filter?

Is the 'Filter Removal Tool' the manual speaks of the typical one used on cars? (The strap that locks around the filter housing.)

This is my first inboard and first diesel...

Thanks!
Check out the specs here.

http://www.marinedieseldirect.com/universal/200157/universal-owners-manual-m25-specifications.html
 
May 24, 2004
7,164
CC 30 South Florida
Get a manual vacuum pump to soak out the old oil. You will not get it all so when refilling do it slowly by adding and checking, repeat until you get a fraction short of the full line on the dipstick.
 
Feb 26, 2004
22,986
Catalina 34 224 Maple Bay, BC, Canada
Lake Lanier

Since you're on the lake, please find our friend Dottie Toney who is the fleet captain of a very active Catalina 34 Association, including many other vessels. Not only a lots of fun group, but a great resource for your inevitable questions.