Whatever that stain is it isn't the current cooling system leak problem. The successful pressure test eliminated the possibility. That is, if the pressure test is to be believed. It makes no troubleshooting sense to perform a test and ignore the results.
However, I reviewed the pressure test protocol described in post #48, item 3. There is still one component that can deliver water into the crankcase that remains untested, assumed good because it's relatively new: the raw water pump. This is the third time I've mentioned it in this thread and it needs to be tested if for no reason other than to eliminate it positively without the assumption factor.
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others
This is the third time I've mentioned it in this thread and it needs to be tested if for no reason other than to eliminate it positively without the assumption factor.
Neil -- sorry, didnt mean to minimize your comment -- i will park the verdict on new MMI until proven innocent.
So i can use the same pressure test procedure on the water pump, eg plug one end, bike pump at the other and see if pump holds 20 PSI?
I apologize as well, been aggravated lately with some post content (not yours).
I cannot say that the pump will hold 20 psi but neither can I say it won't. I recently performed a full cooling system pressure test, pump and manifold included that held 5 psi for two weeks. IF there's a pump seal leak it should make itself known @ 5 psi IMO.
I'm not completely convinced the pump is the culprit but in truth, it's the only component remaining with a water/oil interface that has not been fully tested. As I said, this may be an exercise in eliminating it.
The intermittent nature of the water intrusion has me scratching my head. Changing out the H2O pump appeared to cure the problem only to have it reappear a few months later.
Maybe there is a pinhole leak in a cylinder that was blocked in the pressure test. Perhaps by a piston ring? So repeat the pressure test with #1 at the top of its travel (compression or exhaust) then repeat the test with #1 at the bottom of its travel.
I've never torn an A4 down (and hope I never have to) so I'm really talking through my hat here.......
This advice and $5.00 will get you a small coffee at Starbucks (where have I heard that before?)
BTW: Did you retorque the manifold?
The intermittent nature of the water intrusion has me scratching my head. Changing out the H2O pump appeared to cure the problem only to have it reappear a few months later.
Maybe there is a pinhole leak in a cylinder that was blocked in the pressure test. Perhaps by a piston ring? So repeat the pressure test with #1 at the top of its travel (compression or exhaust) then repeat the test with #1 at the bottom of its travel.
I've never torn an A4 down (and hope I never have to) so I'm really talking through my hat here.......
This advice and $5.00 will get you a small coffee at Starbucks (where have I heard that before?)
BTW: Did you retorque the manifold?
TRUE GRIT
Au contraire - your post makes a helluva lot of sense. I too am not convinced the block is sound. The manifold would indeed pass a pressure test even if leakage were occuring from that stud. Breaches in cylinder sleeves almost always develop low in the cylinder's travel and may not be detected until an engine is torn down (remember Ebben?). I concur with John; test the block again and while the pressure is on rotate the engine.
I have mentioned periodic water in oil earlier in this thread. After some oil changes this winter, launch on Saturday, and running for 30 mins or so yesterday, oil looks good now.
So question is where did water in oil come from late last season?
1) I had one episode of leaking thermostat housing. Water sprayed around head so possible intrusion through plug holes (even though plugs tight)?
2) Excessive healing on wild ride one day? But exhaust loop seems pretty far above waterline
3) Neptune messing with me for laughs
A few reminder facts from last year. Oil level never went much above normal, so couldnt have been much water. Pressure test appeared fine on block, manifold. New Moyer water pump.
At this point, will keep running and keep a careful eye after every sail. Thanks for prior concern and hope i'm not back at you on this one.
Whippet, no it would of been fun to mess with you a bit but I have been occupied elsewhere.
Perhaps the water you speak of was just a bit leftover form the original episode. It can take a long time to get it all to BOIL off as you can't possibly get it all by sucking it out with the oil.
Keep an eye on the filler cap after running, once it cools it should be dry or oily but no moisture. The moisture will appear as long as there is still some in the oil.
As part of this episode, I read Don Moyer's writing about the steel pipe plug that can go bad.
Has anyone ever replaced this -- and is it recommended as part of "preventable maintenance"? My serial number is over 194,000.
From Don Moyer guide to "water in oil"
2) Remove the valve cover to inspect for water entering into the valve chamber through a hole in the very center of the water jacket behind the valve springs. In some of the later model engines (usually with serial numbers over 194,000), Universal used a 1/4" pipe plug to close a hole in that area. The problem is that they used plain steel plugs which have a strong potential to fail after the 25 or so years since they were installed.
Steve, I would not just replace "the plug" unless I was in the valve galley. I would probably inspect the plug when adjusting the valves though.
I would also "goop the plug up" with P'tex #2 when doing an R&R.
I have several gallons of various grades of Mobil 1 sitting here. Already paid for and nowhere to use it. I have to pump out the grey water/oil mayonnaise from my A-4 soon. Any problem doing the flushing-oil- changes with a synthetic oil to get all the water out before before changing back to the 30 weight oil I typically operate the A-4 with?
It's OK to do that...just run the engine a couple of minutes prior to changing it again....if you use the boat the reversing gear may not work properly but to start up the engine, let it run a few minutes and change again....do it 3 to 5 times...should be fine. FWIW I use 15w40 diesel oil in mine and have for a number of years now...engine runs quieter and the oil has better protection...ensure you don't put synthetic in for your last change when you put the engine back in service.
Ryan, are you sure the water got into the oil? IE did the oil level go up?
The good thing about water is it is heavier than the oil and will "just sit" at the bottom until mixed up by cranking or running. If you did not crank a bunch you can suck the water off the bottom, then run the engine with that oil to emulsify the bit left and then change the oil. May only need it once. The water will also evaporate away in a warm engine while running. The water won't hurt anything unless it is allowed to sit, get it out ASAP.
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