Logo

Merc 470 popping oil filter seal Need a Guru

sasngang

New member
"Sorry this is a bit long, but

"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? 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."
 
"time for a new bypass valve.

"time for a new bypass valve.

when they stop working, the first item to start leaking is the oil filter gasket. Make sure you install it oriented correctly."
 
"Use a quality oil filter; Mer

"Use a quality oil filter; Merc., AC, Purolator 1, NAPA, WIX - stay away from FRAM; poor quality. Also prime the filter w/fresh oil before installing it."
 
"Makomark and Guy Gaspar... Ar

"Makomark and Guy Gaspar... Are you thinking there may NOT be contamination in the lubrication path after the oil filter??? That would be great news. How likely is it that a deteriorated oil filter could pass contaminates into the lub system?

I will replace the bypass and go to a different filter (primed before install), but please give me your thoughts on the above.

Thanks for any help on this."
 
"Possible, yes; likely, I thin

"Possible, yes; likely, I think no. If there, are they from the filter? Again, I wouldn't bet on it. If there is crud in the gallies, the first time full oil pressure hits it, it will be blown out into the bearings. Hard to say being as you don't have any history. If that's the case, its time to pull the engine.

I'd keep an eye on the oil once you get it running. Any return of the 'coffee syndrome' will indicate you have another water leak source than the omitted filler cap (let's hope that was the cause, not a manifold or block issue from no/poor winterization).

The valve opens, usually during a cold cycle, when the oil is thick, to keep the oil pressure seen by the filter to a reasonable level. If it is stuck close, the filter can see well above its burst pressure (most are 300 PSI). the gasket is the weak link and usually goes first. I've seen engines where the filter was wrenched down so the gasket 'wouldn't leak' - they were right - the canister cracked!"
 
"Guy Gaspar, please keep in mi

"Guy Gaspar, please keep in mind that 1 month ago I had the motor running fine with good oil pressure. Then after sitting 4-6 weeks without running at all, the water was still emulsified in the oil (milky look). AND I think the block on this engine is aluminum. Could you clarify where you might think the rust could have caused the restriction?

Are any special tools required to replace the valve? I haven't been back in the boat since yesterday."
 
""...sitting 4-6 weeks wit

""...sitting 4-6 weeks without running at all, the water..."

Over that period some water could separate out from the oil. Add a little O2 and rust forms on steel and iron components which is how some engine cylinders sieze. Hope not."
 
"The 470 is an aluminum block

"The 470 is an aluminum block engine, it also comes with a closed cooling system. If the system had good anti freeze which is also an anti corrosive, I think your chances of corrosion are pretty small. I would guess the by pass valve is bad or you just have lots of sludge in your system. Try the by=pass valve first with a fresh oil change and add some seafoam. Run your engine for a couple of hours and change the oil and filter again. See if that helps. If your system was clogged too bad you would hear your lifters clattering pretty bad. Good luck."
 
"Well, my worst fears have sur

"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."
 
Per SELOC SM #7

Some oil go


Per SELOC SM #7

Some oil goes to #4 crank shaft bearing and the rest is routed to the main oil gallery located above the camshaft and runs the entire length of the block.

JMHO: Use of an oil filter w/a synthetic media vs. paper would prevent media distruction. I use them in my SUV's and truck; probably should start using them in my boat.
 
"If the filter media has '

"If the filter media has 'disintegrated', something besides oil and water has been added to the crankcase."
 
"Guy, Yes I will also be conve

"Guy, Yes I will also be converting to a synthetic core filter in all of my vehicles (especially my boats!), any suggestions on brand or model of filter to use with a synthetic core?

Does anyone know if there are any areas of access to the lubrication path where I might be able to back flush upto the oil filter galley?"
 
Great Article - Yes I can agre

Great Article - Yes I can agree with Mobil 1 filters... Merc filter for the boat seems like a good idea too. Do you know if the Merc filters use synthetic media?

There was no response on the a possible solution to back flushing the lubication system. Anyone have any thoughts (aside from complete disassembly and flush?) I don't know that this boat is worth that much work.
 
I haven't touched a 470 bl

I haven't touched a 470 block in a while but seem to remember it having the galley plugs like most 4-cycle blocks. Getting to them would mean removing the front cover and the flywheel. You could always check the parts breakdown/service manual to get a better fix on their locations.
 
"Do you know if the Merc f

"Do you know if the Merc filters use synthetic media?"

Don't know; google them.
 
"Yes, there is a plug in the e

"Yes, 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???"
 
I haven't yet looked at th

I haven't yet looked at the Pressure Releif Valve in the oil filter area. Someone mentioned that it must be installed in the correct orientation. Can someone shed some light on what needs to be done there... or is it somewhat obvious?
 
I'd be inclined to run s g

I'd be inclined to run s galley cleaning brush thru first - like running a snale thru a pipe. If there's any 'filter residue' the brush may 'grab' it. a fluid flush by itself may send it somewhere else you don't want it.

the flush after the brush should get any 'free' remnants afterwards.
 
"That's a good idea. Is t

"That's a good idea. Is the gallery the same size as the plug (shows as 5/8")? And do you know if this is a pressed in plug or a treaded item? I've never had one apart, so any info you have would be helpful.

Thanks to all for the input."
 
"SOLUTION!!!! There IS a plug

"SOLUTION!!!! There IS a plug (1/8" pipe thread) on the side of the engine near the rear of the oil gallery (easy to get to). We back flushed to the oil filter area. Found no contamination (Yea!). Added about 50% fuel oil to the oil and started the motor. Blew out the oil filter seal again! (OH No!). I reseated the seal and really tightened the oil filter down, then restarted the motor and the seal held. We flushed the lubrication system 2x using 50/50 fuel oil and new oil. Then finally replaced the oil filter and added all new oil. Works fine, running 60-80 psi oil pressure.

I paid to speak to a local Merc technician today. He suggested the oil viscosity increases dramatically when mixed with water/coolant and it was possible the high viscosity was causing the seal to pop out of place. At this point I would have to agree, that was likely my problem. He (Randy of Reeds Marine - Delavan, WI) also indicated the most common places where water/coolant can enter the engine. 1. where the coolant reservoir attaches. 2. the exhaust riser 3. The camshaft/coolant impeller seals (2).

I want to thank you all for your input and help, you have been a blessing!

Thanks again! Steve"
 
Back
Top