Merc 470, oil forced out at oil filter. Need a Guru.

[sasngang]

Sorry this is a bit long, but I want to give all the detail.

OK, this is a new (old) boat for me. 1983 Galaxy Bow Rider with 470 I/O purchased from storage facility (so I have no history). Before I did a bunch of work to it I checked oil (looked OK), cleaned carb and flushed fuel system. Started and ran the boat for about 15 minutes on local lake. All seemed well. Then the boat sits for a month or so before I can get back to it. Replaced bellows and gimbal bearing (fun job). Go to start and run it in the driveway with cups and ended up with a 3/8" stream of oil shooting out of the engine side. Turns out to be the seal for the oil filter... Weird! To compound the problem, the oil is a milky brown (like coffee with cream in it). So obviously there was water in the oil pan. When I purchased the boat (late winter), the oil filler cover was off, so it's possible that the water was in it when I took my initial 15 minute lake spin (seperated and sitting in the bottom of the pan) and then during the lake joy ride it mixed together with the oil.

Anyway... After shutting the motor down to stop the oil fountain shooting 10' into my yard, I drained the contaminated oil out and replaced the filter and oil. Upon the restart the new oil filter gasket popped out of place (almost immediately) squirting more oil all over the place. Obviously the oil pump is working!

Here's what I think might be going on. Once the water mixed with the oil it contaminated the oil filter. The water in the filter caused the paper filiments in the oil filter to disintegrate inside. Then when I restarted the motor (a month later), the filter material was allowed to enter the lubrication system and clogged it up at the 1st small clearance area (at least).

Does this seem right? If so, can anyone shed some light on where that 1st place might likely be? OR what the block lubrication path is (after the oil filter). I would love to avoid disassembling the entire motor to figure it out (although that may be necessary anyway).

I guess I don't understand the By-Pass valve completely. To me it looks like it should dump any un-used pressurized oil back into the pan... So "if" the lubrication system was plugged up someplace after the oil filter, "then" wouldn't all the extra pumped oil end up going thru the by-pass back into the pan?

This is a link to show the block and bypass valve. http://www.mercruiserparts.com/Show_Pictures3.asp?dnbr= 99958&ivar=images/CRUISER/99958/21.png&inbr=1075&bnbr=100&bdesc=CYLINDER+BLOCK%2 C+ OIL+PUMP+AND+OIL+PAN

I do not have much hope of any easy solution, but any help or other thoughts/ideas would be appreciated.

 

[Bondo]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Ayuh,... Have you removed,+ Checked part #7, the oil by-pass,..??

 

[Don S]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Take the oil filter off and look! Also check to see if there is 2 filter gaskets.

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Are there 2 pressure releif valves? One in the oil filter cavity and one built into the oil pump?

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Well, my worst fears have surfaced! After inspecting the old oil filter, the media indeed has deteriorated and is coming out of the filter. It appears as very small wads or tufts of cotton/wet paper. The next question is: where is the most likely place of restriction/contamination of the lubrication system downstream of the oil filter??? Does anyone know?

I assume the motor will need to be pulled and completely cleaned unless I can locate the 1st restriction area. If I can find that area, it may be possible to remove the restriction and then flush the whole system out with a mixture of fuel oil and engine oil with a couple of new oil filters.

Of course this does not explain why the neither of the 2 pressure releif valves are re-routing the oil back to the pan. I guess I should be thankful, in that, I avoided running the motor without lubrication.

ANY Thoughts will be appreciated.

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Someone suggested that there is a plug in the engine front to the oil gallery. Can anyone think of a reason I wouldn't want to back flush the lubrication system from there to attempt to remove the contamination from the oil filter particulate?

Here's my thinking... The blockage is most likely at the 1st restricted area after the oil filter point. IF I can send pressurized fluid the opposite way thru the lubrication system, I may be able to flush the contamination out without having to completely dismantle the engine. ANY THOUGHTS???

 

[searay3]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Well, my worst fears have surfaced! After inspecting the old oil filter, the media indeed has deteriorated and is coming out of the filter. It appears as very small wads or tufts of cotton/wet paper.

I am very interested in what could have caused the filter to break down like that. Never seen water in the oil do that. But I never had an engine with water sitting in it for very long be worth starting. Did you use some kind of aggressive solvent in the oil maybe to clean/flush the engine? I would think it's a gamble to even attempt to flush it out without a complete teardown, block boil in chemical etc. The passages in the lifters, the tight clearances of bearings, rockers, etc. would not allow passage of debris larger than a couple of thousanths. IMHO, tear it down. You risk bearing/crank damage or cam bearing damage if it starves for oil.

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Nothing was added to the oil (that I am aware of). But then I don't have a history on the boat either as it was purchased from a storage facility. When purchasing it, I did check the oil dip stick that showed oil in the case (not milky looking). AND I did get it started and running before attempting any other repairs.

The boat sat for 4-6 (maybe 8) weeks before running it again in the driveway with cups. The engine fired almost right away and ran for maybe 10 seconds before popping the oil filter seal. After I replaced the oil and filter with new, the new seal popped almost immediately after the engine start.

I agree that oil starvation to any of the internal components is BAD, but don't think I can justify completely dismantling the engine for cleaning and reassembly (I would guess a $500 cost at a minimum, with me doing most of the work maybe 15-20 hrs). The boat doesn't have that kind of value... and I am not interested in throwing money at an upside down depreciating asset. SO I might give it a shot.

We just replaced all 3 bellows and gimbal bearing. Outdrive ran smooth when on the water.

What to do???? |

 

[Gary H NC]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

All of this still does not explain the milky oil...or how it got that way..
Best of luck...

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

If you read the original post, I think you'll see my thoughts. It may have gotten in as a result of the missing oil filler cap. BUT, you are correct. I do not know for certain if there is an interal water leak. AND I wont know unless we disassemble and inspect... OR get it running and watch the results. Are there any other options you can think of?

 

[Gary H NC]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

I wish i could help but i avoid those engines. The most i do to them is a tune up and oil change.
Some of the other guys here really know the 470...

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Thanks for the reply.

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Good point. But why then didn't the seal oil filter seal pop out during my initial 15 minute joy ride? I guess it could be coincidence.

 

[parrisw]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

See if you can pull the relief valve apart and free it up. Then if that works, run it with fresh oil, and monitor to see if more water gets in there. Is your engine fresh water cooled or raw water cooled? If fresh, check to see if the level is low.

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Here in WI it would be used in fresh water only. It does have the isolated cooling system (4" canister), but I did wonder if I could convert it to a raw water system easily.

I hope to tear into it later tonight. My gut tells me to attempt to back flush the oil gallery toward the oil filter inlet, then to inspect the pressure releif valve in that same area and finally refill with oil and try to start it again.

 

[parrisw]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Here in WI it would be used in fresh water only. It does have the isolated cooling system (4" canister), but I did wonder if I could convert it to a raw water system easily.

I hope to tear into it later tonight. My gut tells me to attempt to back flush the oil gallery toward the oil filter inlet, then to inspect the pressure releif valve in that same area and finally refill with oil and try to start it again.

You need to try to free up the relief valve, its stuck for some reason, best way is to pull it out, you could try to back flush it wont harm anything.

 

[JustJason]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

My gut tells me you need to buy a new oil pump....

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Yes, I'll work on the releif valve. The reason for the back flush is to try to remove the contaminates that "MAY" be in the system from the oil filter guts. (see the earlier posts).

I noted that one of the gaskets for the impeller cover is NLA (27-72099)... Can that be right?!

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

Why buy a new oil pump? The one in the motor is certainly pumping oil.

 

[sasngang]

Re: Merc 470, oil forced out at oil filter. Need a Guru.

ParrisW - Are you talking about the pressure releif valve (PRV) in the oil pump OR the one by the oil filter? I can get to the PRV by the oil filter easily. Do you have any suggestions or instructions for removal, inspection and reinstallation on that one?

Getting to the oil pump is a much larger project. And I am not ready for that just yet.