5.0 MPI real world oil change how much did you add?

[Presentation]

I was reading another members post regarding changing the oil in a 7.4L big block V8. I was surprised that at least one member got almost all the oil out based on the stated capacity via the dipstick method.

I have the small block 5.0 MPI V8 and use the ‘suck it out the dipstick’ method.

Per my official mercury marine manual #31 the total crankcase oil capacity with an oil filter change is 5 ½ quarts.

I suck out all I can, remove the oil filter, suck again, install new oil filter, add oil, run engine for a bit, check dipstick then add if needed. Check again the next day or so.

My real world amount of oil that I need to add after sucking out all the oil I possibly can, only air remains plus changing the oil filter is 3 1/2 quarts.

This amount was the same on both of my engines.

I’m asking how this compares to other members who also have a 5.0L MPI motor.

 

[jason78]

I believe my manual says 4 quarts capacity. I will check will check when I get home. Initially I was worried because I only got about 4 quarts out. A mechanic told me some of the manuals had a misprint. Ill let you know what I find.

 

[Lazy Daze]

I'm surprised that's all that came out. When I suck it out the dipstick tube (with an identical engine to yours), I'll put in a solid 4-1/2 quarts. If I suck it out the "quick drain", it'll be a solid 5 quarts.


EDIT: Disregard this next paragraph - I didn't read your initial posting thoroughly enough.

Did you run it after you changed it to verify oil level? The lines to and from the remote filter assembly (along with the filter, of course) will account for about a 1/2 quart so if you don't run it, leave it a little high (half of the distance represented by the "cross hatch"). But even at that, it leaves you shy.



Was the engine at least close to being level?

Was it full before you started? Maybe the level was down to start with?

 

[jason78]

OK, now that I am at a PC rather than the Blackberry app....


The Capacity according to my Owners manual is 4.5 quarts (see pic below). My owners manual was revised in 2004. My #31 Mercury Manual States the capacity at 5.5 quarts as you has seen. My #31 was printed in 2001.

I was puzzled with the 280 initially since my 03 225WE with the same engine called for 5.5. When I changed my oil on the 225 it was with the pan hose. As I recall it took 5.5 and stayed in the normal range.

Whenever I changed my 280 oil the first time, (which I had emptied with the tube) I noticed that it was showing full after 4.5 quarts. (I always put in 1 quart less than recommended then start checking as I add the last quart. I also fill up the filter half way before re-installing.)

It was then I talked with a Merc mechanic and was told that the early manuals were a misprint, that they only take 4.5 as reflected in my later manual.

My "theroy" is that the true capacity is somewhere between 5 and 5.5 quarts. I "think" that what may have been happening was people doing tube changes were not getting all the oil out and ended up adding an extra quart with each change when adding 5.5 without checking. They figured it was better to print 4.5 and have the pan guys ~1 quart low than have the tube guys (ones not paying attention as they filled) running a quart high. Again, this is just theroy.

I have changed my oil twice and my friend's oil once by the tube ('03 300DA T5.0MPI). I can tell you on all 6 engines, 4+/- quarts was removed from the tube and 4 quarts was added back in as new to bring it in to the Normal range on the stick. I know it was 4+/- quarts because I was able to dump the oil back in to the gallon containers form the change bucket. Of course there was some oil left in the bucket and in the old filter so thats why I say 4+/- quarts.

Final thoughts- I believe the true capacity is 5~5.5 quarts and that the tube removes 4~4.5 quarts. I just check, add, check, add, run the engines, check again.

* Also, the footnote indicated in my manual states "Always use the dipstick to determine the exact quantity of oil required"

 

[wish2fish]

I get a full gallon out using my plug drain. It takes forever. is this normal?

 

[jason78]

I get a full gallon out using my plug drain. It takes forever. is this normal?

If you are talking about the length of time, then yes, I believe it is normal. I was about 10 minutes in to my first change on the 225 with the hose when a dealer mechanic walked by and asked what I was trying to do and told me I would be there forever. He then brought out the pump bucket, hooked on to the end of the hose and done deal in less than a minute.

I would say get a pump bucket.

 

[wish2fish]

If you are talking about the length of time, then yes, I believe it is normal. I was about 10 minutes in to my first change on the 225 with the hose when a dealer mechanic walked by and asked what I was trying to do and told me I would be there forever. He then brought out the pump bucket, hooked on to the end of the hose and done deal in less than a minute.

I would say get a pump bucket.

tell me more! how did he hook to the hose?

 

[jason78]

tell me more! how did he hook to the hose?

He just stuck the hose from the Jabsco oil changer right over the end of the fitting on the end of the oil change transom hose and sucked away.

The Jabsco unit (I believe) comes with the right hoses.

The Shurflo changer needs the hose and fittings modified to suck oil at a reasonable rate. That is what I use and it comes with the thin tube to stick all the way down the dipstick tube. We had to change the tube to get it to to fit around the dipstick tube then it still pumped slow as he** so we changed out the fitting that attched hose to pump because the orifice was too small- problem solved.

Save time and trouble and just go with the Jabsco unit. It will make your life easier.

 

[Presentation]

Thank you Jason!

 

[wish2fish]

Pres,
I don't know what type of pump you are using but I have an old hand oil pump. When I helped my brother change his oil through the dipstick I had to replace the tube with a longer piece to get to the bottom of the oil pan. I just used refrigerator ice maker tubing.

 

[jason78]

The problem I had with the thin hose that goes down to the pan was that I could not tell when it got to the bottom and it started coiling up in the pan. First time I used it on a buddy’s boat we thought we had all the oil out but were able to get even more from the top of the dipstick. Also due to the small size of the tube going to the pan it was a painfully slow process. After speaking with some of the mechanics, they told me they always attach to the top of the tube and told me other shops they had worked at do it the same way. They also told me they never use the remote transom hose even if the boat is in the shop.

Based on my experience thus far, I think most should be able to be sucked out of the tube. After changing the oil and running the engines, there are no obvious signs of “contamination” from old oil that was lurking in the pan. This does leave the possibility of a buildup of sludge in the bottom of the oil pan. Since my boat has always been slipped I don’t think it has ever been done from the hoses.

When I do my next oil change in the Spring, I will be switching to Synthetic. I will do that when it is out of the water so I can use the transom hoses and probably try and coordinate future changes with my Spring and Fall pull. I had thought about buying extensions for the hoses so I could get to them without going through the drain plug but the hoses are pretty expensive.

On a side note, my friend who has a 340 with 8.1s does not have a remote hose so he has to use the tube. He seems to be able to get 9 quarts out, which is his stated capacity. I seem to remember a discussion here on CSR a while back where it was said by “someone in the know” that all of the later model Merc engines were designed to suck from the top of the dipstick tube and get most of the oil but there was a risk of sludge buildup over time in the pan. Maybe Boat Tech will see this and comment as I am sure he would know.

I would love to see a pic of an oil pan off an MPI engine to see how it is designed.

 

[Lazy Daze]

Yes, always avoid sticking a little hose inside the dipstick tube, if you can - it absolutely is "painfully slow" when you use a smaller diameter hose. That being said, our preferred way is to suck it out through the "quick drain oil hose". If that's not available, then stick your oil sucker hose right on the top of the dipstick tube... 3/8" inside diameter hose, if memory serves. We use the same diameter hose when going through quick drain - we just screw in a $3, 3/8" male pipe to male barb adapter (by hand - doesn't have to be really tight).

 

[wish2fish]

Dennis,
How low does the dipstick go into the pan? Just wondering because if you used the dipstick top connector there would have to be a little oil left.

 

[Lazy Daze]

Dennis,
How low does the dipstick go into the pan? Just wondering because if you used the dipstick top connector there would have to be a little oil left.

You're right, there is a little left when going through the dipstick. That's why we use the quick drain whenever possible. I can't say "exactly", but it seems like I get about 1/4 to 1/2 quart more out when going through the quick drain.

 

[Gunn]

Dennis,
How low does the dipstick go into the pan? Just wondering because if you used the dipstick top connector there would have to be a little oil left.

That was my concern when I read to do it that way. By sucking out of the top attachment to the dipstick, I doubt the dispstick tube goes all the way to the bottom of the pan. And if not, you're no going to get it all. The hose inserted into the dipstick might take forever, but at least you're on the bottom of the pan. My unit has a pretty stiff hose and I can hear it knocking against the bottom of the pan when I push it down there.

 

[jason78]

That was my concern when I read to do it that way. By sucking out of the top attachment to the dipstick, I doubt the dispstick tube goes all the way to the bottom of the pan. And if not, you're no going to get it all. The hose inserted into the dipstick might take forever, but at least you're on the bottom of the pan. My unit has a pretty stiff hose and I can hear it knocking against the bottom of the pan when I push it down there.

Honestly I don't think you are going to get much more oil like that (we’ll call it the “straw method”) than just using the tube. I only say that because this was discussed a while back and I seem to recall someone posted a pic of a late model Small Block oil pan and the tube does go pretty much to the bottom. I think the reason it does not get the last ½ quart or so is because the tube is towards the front of the pan so unless to can get a line beyond the base of the tube I think it is going to be the same result as using the tube. I have searched this morning and cannot find that thread so it is possible it may have been on another forum or maybe I am just crazy.

I think no matter what you do, there is no way to get 100% of the oil out, especially if the engines were recently run to warm up the oil. Everyone has to do whatever they are comfortable with. Like I said, I will use the transom lines next time, mainly because I am switching to Synthetic and want to get as much out as possible.

I just don’t get why Merc would not just make the hose longer so it could be easily used in while in the water. Or make a reasonably priced (in Boat dollars) extension for the hose for those who wanted it.

 

[Woody]

Honestly I don't think you are going to get much more oil like that (we’ll call it the “straw method”) than just using the tube. I only say that because this was discussed a while back and I seem to recall someone posted a pic of a late model Small Block oil pan and the tube does go pretty much to the bottom. I think the reason it does not get the last ½ quart or so is because the tube is towards the front of the pan so unless to can get a line beyond the base of the tube I think it is going to be the same result as using the tube. I have searched this morning and cannot find that thread so it is possible it may have been on another forum or maybe I am just crazy.

I think no matter what you do, there is no way to get 100% of the oil out, especially if the engines were recently run to warm up the oil. Everyone has to do whatever they are comfortable with. Like I said, I will use the transom lines next time, mainly because I am switching to Synthetic and want to get as much out as possible.

I just don’t get why Merc would not just make the hose longer so it could be easily used in while in the water. Or make a reasonably priced (in Boat dollars) extension for the hose for those who wanted it.

Have you actually priced this out? I shouldn't be that bad.

 

[jason78]

Have you actually priced this out? I shouldn't be that bad.

As far as I know there is not one to price out.

I guess it could be made if one had access to the correct hose and had access to what is needed to add the brass compression fittings to the hose.

 

[Lazy Daze]

I agree - I don't think there is really that much difference between the "straw" and "tube" method. I've never looked at the tolerance before, but I vaguely remember asking a technician this a few years ago - his response was that the tube is actually a lot closer than what most would think and that using a "straw" wouldn't offer any advantage.

You guys are right - the extension would be very easy. Although, I remember working on a boat about a month ago where the quick-drain hose was actually routed up the back side of the engine and was laying on the top of it (backside meaning flywheel side... just in case anyone with v-drives is reading this). I remember thinking "Huh - I didn't know the hose was long enough to reach all the way up here".

 

[jason78]

You guys are right - the extension would be very easy. Although, I remember working on a boat about a month ago where the quick-drain hose was actually routed up the back side of the engine and was laying on the top of it (backside meaning flywheel side... just in case anyone with v-drives is reading this). I remember thinking "Huh - I didn't know the hose was long enough to reach all the way up here".

Dennis,

I wonder if there were different lengths. I feel if I could turn mine 180 degrees and have it come under the engine I would have enough length to get to it with the pump hose. Right now they go through a drain hole in the stringer and lay in the back center of the bilge.

I have always been afraid to turn the L-Shaped fitting that connects the hose to the oil pan for fear that it would loosen and start leaking oil. I wonder if the L-Connector has a swivel built in or if it is a hard 90 degree fitting? Never held one just saw a drawing in a diagram once.

Jason