Engine oil type

[Mike and Joanne Stimmler]

I am getting ready to change the oil on my Cat 34's  m25xp for the first time since I bought it. I see that the manual recomends a 30w or 10w-40 with a CF,CF-4 or CG-4 designation. Anyone have a favorite brand? I see Shell Rotella 15w-40 as well as Castrol DELO 15w-40 and Valvoline Premium blue diesel.I know that the CF designation is critical but how about the weight? Ron has talked about Mobol 1 Synthetic oil but would there be any problems using this on an engine with high hours on it (3000). Also everyone seems to pump the oil out of the dipstick hole. Is there anything wrong with just using the drain plug? I know some boats have drain hoses attached to the drain plug fitting(mine doesn't)is this a good idea?

Thanks,
Mike

[Ted Pounds]

I too use Mobil 1, 10w-30.  It's great for high time engines.  Where you don't want to use it is on a new engine as it wont break-in properly.  I found that out the hard way with my first new car.  I have the drain hose on the oil pan plug.  It works great.    I connect to one of those gas can like things with the hand vacuum pump (I can't think of the brand name  ).  You can just drain it out the drain hole, but I think you'll have trouble getting a big enough container under there to catch all the oil.  If you want to add the drain hose you'll probably have to pump most of the oil out the dipstick first.

[SteveLyle]

This is probably a good candidate for one of the 'questions of the month' - what oil do you use and how do you change it?  Lots of options and opinions.

I stick with the manual recommendation.  Multi-weight is really intended for cold weather operation, 30w for 'normal' operation.

Re: synthetic.  Synthetics have two advantages that I'm aware of - their additves last longer, and they 'cook' at a higher temperature than organic/natural oils.  The first advantage is a moot point for me - I change my oil annually, and have never put more than 50 hours on the engine in a year.  The second point is a peace of mind topic - your engine temp alarm goes off at about 200 degrees or so.  Normal oil breaks down at approx 250.  Synthetics are ok into 300 degrees plus.  A larger margin of error.

The only 'con' I've ever heard of for synthetics is cost.  Which obviously gets into opinion - how much is the extra peace of mind worth?

I've never heard of a problem with synthetics and high-hour engines.  I have heard of concerns about lightweight oils (e.g., 5w30) and high hours.  Nothing major, just a bit more oil burning due to slipping past the rings and valve seals.

The oil change options I'm aware of:
1) Use a hand pump, from either the dipstick tube or the drain hose.
2) Use a vacuum pump, from either the dipstick tube or the drain hose.
3) Use the drain plug.

Option one is likely the most popular, lots of people have hand pumps and drain hoses.  But I've never done it this way, so can't speak to it directly.

I've used options 2 and 3.  Option 3 was the choice of the first C34 Tech Editor, it's written up in an early Tech Notes.  Use gloves, get the largest container you can find that will fit under the engine (16 oz cups, or a cut down gallon jug work).  Have plenty of paper towels handy.  Open the drain plug, fill the container, holding it in your right hand.  When it's about full, stop the oil flow with your left thumb, dump the contents of the container into a jug, replace it, remove your thumb, etc..  It works, I've done it this way, but it can be messy if you slip up.

Option 3 is my favorite.  I use an Oil Boy fluid extractor, it was $60 at West.  Stick the extractor tube down the dipstick tube, pump it about 10 times, and the resulting vacuum pulls the oil out.  When it starts sucking air, I remove the drain plug and get the last pint into a cup, then suck that into the Oil Boy.  All done in about 5 minutes or less.  The Oil Boy works great on power equipment and cars as well.

Steve

[Stu Jackson]

I adapted the end of the oil change hose with fittings from a plumbing store to connect directly to a Par hand pump. 

30 W synthetic Mobil 1 or equivalent.

Try searches on the words "oil" and "change" - you'll have to wander through other topics with those words, but this is a popular subject.

[Robert Mann]

I use Pensoil marine diesel oil 15W 40.  Previous owner used Amsoil, which seemed to do just fine.  I don't know much about synthetics except in very high load applications and as our usage is far from that I stuck with mineral oil.

To change it I have a Jabsco pump that is driven from an electric drill.  It connects to the drain extension hose and gets the job done in a very short time, (don't let the hose slip out of the milk jug you are collecting the old oil in!!).

[Ron Hill]

Mike : As you said I like Mobile 1, but any synthetic will do the same job.  Be careful as I picked up one synthetic brand on sale and when I got home found it was NOT rated for diesels ("C" for compression and "S" for spark ).  Took it back and traded it in on a C rated synthetic. 
On your older (hi time) engine watch and see if you start burning oil.  If so you might want to try a synthetic blend.   

[Mike and Joanne Stimmler]

Ron, I use Mobil 1 in my car so I think I'll try it in the boat. Am I missing something on the draining explanation? Why would you have to pump the oil out if you had a drain hose? Wouldn't it drain out by gravity as it would if you used a drain plug? It wousd seem that a drain hose is just a convenient extension of the drain plug.

Mike

[Stu Jackson]

Mike

The drain hole is at the bottom of the oil pan.  There is almost NO clearance there.  I've tried the "Herb Schneider" method mentioned above, then the dipstick, now my new fitting on the end of the oil hose.  The first method required disconnecting a sensitive nut and using a finger encased in a plastic glove on hot oil, the second -- a thin dipstick that took a long time to work  --  the smaller the hose the longer it takes to move the oil; then my use of the hose, which is around a 3/8 inch, to match the 3/8 inch on the Par hand pump.

Here's a picture of my design sketch.

[Mike and Joanne Stimmler]

In changing the oil is there a problem with taking out the drain plug? It should be the same as the drain plug on my car or am I missing something. It looks like I have room to get at the plug but the space is a little narrow to get a collection pan in there but I think I can find something to fit. Are the drain hoses available from Catalina and do they just take the place of the plug?
Mike

[Stu Jackson]

Mike

There shouldn't be a "problem" removing and replacing the drain plug.  I believe that since people have found easier ways to do it, why go back to the "dark ages?"  I tried it that way the first time.  I used the dipstick the second time.  The dipstick hose is so thin that it reduces the flow, so I came up with my idea to simply connect to the free end of the drain pan hose.

In answer to your other question, try this from Projects:  http://www.c34.org/projects/projects-replaceing-oil-change-hose.html

[Sailing Steve]

I don't know if this applies to any other engine configurations, but on the M35, the cap that holds the dipstick, spins off much the same way the oil fill cap does.  This provides a hole about an inch or slightly larger to insert your pump tube into.  I thought it was worth mentioning in case others where unaware of this, or perhaps I'm misunderstanding the comments regarding the small size of the distick tube for pumping oil out of the engine.

Steve
'90 L'Abri
Hull# 1080