Oil Pressure Dropping

[edwardc]

There's only a limited number of places that could leak that much oil.
One, (the pressure sender port), you've already found.

Others I can think of are

• The oil pressure adjuster screw
• The capped-off port next to it
• The big plug down low on the block, under the carb
• The rear seal

Any chance you could clean & dry your bilge, spread some talcum powder, run the engine for an hour, and look for trails in the talc?

[sailingchance]

There's only a limited number of places that could leak that much oil.
One, (the pressure sender port), you've already found.

Others I can think of are

• The oil pressure adjuster screw
• The capped-off port next to it
• The big plug down low on the block, under the carb
• The rear seal

Any chance you could clean & dry your bilge, spread some talcum powder, run the engine for an hour, and look for trails in the talc?

Thats my plan for the morning. Instead of talcum powder though I will ahve to use oil cloths. There is no wayI can get all this oil cleaned up without a hose and and dock.and I dont feel right bilge pumping it. I've been putting oil cloth after oil cloth down there to soak it all up.

I will check all those areas. Could the rear seal actally leak that much oil? i did replace the gaskets recently - meaning it was messed with. i dont even know what I could do if it was the rear seal, except disassemble and try and fudge new gaskets. I'm really hoping its one of the other things. lol

[Mo]

You will get it.

If you put a new gasket on the cover recently it should be good. Generally we can reuse the same one there time after time without any problem. If you can manage to pick up some engine cleaner go for it.

Pick up 2 jugs (4 quarts each) of 15w40 as well. I'm convinced she's using so there'll be some left in one after the oil change. You will have what's left of number 1 jug and the second for top-ups as required. After a few days running like you described you will see where you are with it and will know the intervals to check and add oil.

You mentioned you have the old style engine...is there any chance oil is getting up through the oil filler hatch located near the back of that? Rear seal...yes a rear seal can leak a considerable amount of oil over time cruising...also look for tracking on the engine compartment where oil spatter would be slung.

Expect to see consumption drop when you move to 15w40.

[sailingchance]

Feeling a little better....

If you put a new gasket on the cover recently it should be good. Generally we can reuse the same one there time after time without any problem. If you can manage to pick up some engine cleaner go for it.

Pick up 2 jugs (4 quarts each) of 15w40 as well. I'm convinced she's using so there'll be some left in one after the oil change. You will have what's left of number 1 jug and the second for top-ups as required. After a few days running like you described you will see where you are with it and will know the intervals to check and add oil.

You mentioned you have the old style engine...is there any chance oil is getting up through the oil filler hatch located near the back of that? Rear seal...yes a rear seal can leak a considerable amount of oil over time cruising...also look for tracking on the engine compartment where oil spatter would be slung.

Expect to see consumption drop when you move to 15w40.

You sound calm and confident. lol. I wish I felt that way. I dont know where the oil filter hatch is. I dont have any sort of external oil filter. just the screen at the bottom of the pan (which is internal).I really hope it isny the rear sealm it would mean pulling the entire engine again. Weird Vdive setup.

I have some food for thoght and will keep this post updated tomororw when I have cleaned things up and added oil. I think I will have to take her out and run her under load to see what is going on.

Thanks Mo.

[Mo]

You sound calm and confident. lol. I wish I felt that way. I dont know where the oil filter hatch is. I dont have any sort of external oil filter. just the screen at the bottom of the pan (which is internal).I really hope it isny the rear sealm it would mean pulling the entire engine again. Weird Vdive setup.

I have some food for thoght and will keep this post updated tomororw when I have cleaned things up and added oil. I think I will have to take her out and run her under load to see what is going on.

Thanks Mo.

Mispelled....oil filler hatch. I'm calling it a night. Rest up and things will look better in the morning.

[sailingchance]

Mispelled....oil filler hatch. I'm calling it a night. Rest up and things will look better in the morning.

I dont have one of those (that stack that sits on top of the reversing gear plate?) My reversing gear plate is just a plate, shaped like a tombstone.

That said, I do have a weeping leak there. I have cut new cork gaskets. My reversing gear cover has cracks at the screw holes and is a little warped. I am going to try 2 gaskets. Is there a reason at all that I should cut out the center of the gasket? The reversing gear doesnt need it for clearance. It seems to me it would be more effective if it were one piece across the cover (matching the plate)

[Mo]

OK, if the cover is warped a silicone gasket might be the answer. Remove the cork and clean it up with a scraper. Wipe all oil away with a towel or something along those lines.

Next put a bead around on the reversing gear and let it sit for 1/2 hour. Place the plate on the reversing gear after that but don't push down. Genltly start the bolts but don't turn them in and draw the plate down. Allow to sit like that overnight then remove each bolt one by one and put some silicone or locktite on the bolts ...then snug them all in a criss cross pattern. The silicone should make up for any cracks or warp....worth a try.

That said "weeping" doesn't sound like it's pouring oil out there. Have a look near where the shaft and reversing gear meet at the coupling. Look around there and see if oil is on the adjacent bulkheads as it got flicked off by the turning shaft. If you don't see that a major leak at the coupling is not likely.

[ndutton]

I hate what I'm thinking

Jason,

Is there any chance the bilge water is high enough for the engine pan to be sitting in it? For a long time? Like years?

[sailingchance]

Jason,

Is there any chance the bilge water is high enough for the engine pan to be sitting in it? For a long time? Like years?

No, I have bilge pumps out the wazoo. It has not risen that high.

[sailingchance]

Thank you!!!

So, I went through all the possible areas oil could be leaking. I tightened the oil pressure screw 1.5 more complete turns. Checked the oil pressure pipe, sender, the oil fill under the mech fuel pump, reversing gear cover ( made new gasket).I also changed oil to 15W40 as suggested.

I put oil cloths down whereever I thought there might be a leak, and baby powder along the edges of the oil pan gaskets.

I ran the engine today for about an hour in the anchorage, under load going back and forth at about 1900 RPM. Oil pressure started at 40PSI which is normal. It hung around 35 PSI much longer than normal, before settling down to 20 PSI after about 45 minutes of operation. This is where she usually holds.

I checked the engine every 5 minutes, looking for the oil leak that has been dumping 3.5qts into my bilge every 5 hours. I only found a very minute (1/4 teaspoon) of a weep in a spot where the reversing gear housing meets the oil pan. it was pretty high up near the fuel pump though so it cold be just some heated residue that i didnt clean up. Regardless... it wasn't the culprit. I dont know if that means that the failure point required longer operation, or if it means I fixed the problem. Only time will tell.

When I checked the oil, I had the same I amount I started with. So that's good. It was blacker than I'd like, but I'll take.

I am heading out on a 100mile crossing tomorrow and will likely have to motor a bit. I will let you all know how it goes under longer operation. But so far so good.

[Mo]

Not looking too bad at all.

So, I went through all the possible areas oil could be leaking. I tightened the oil pressure screw 1.5 more complete turns. Checked the oil pressure pipe, sender, the oil fill under the mech fuel pump, reversing gear cover ( made new gasket).I also changed oil to 15W40 as suggested.

I put oil cloths down where ever I thought there might be a leak, and baby powder along the edges of the oil pan gaskets.

I ran the engine today for about an hour in the anchorage, under load going back and forth at about 1900 RPM. Oil pressure started at 40PSI which is normal. It hung around 35 PSI much longer than normal, before settling down to 20 PSI after about 45 minutes of operation. This is where she usually holds.

I checked the engine every 5 minutes, looking for the oil leak that has been dumping 3.5qts into my bilge every 5 hours. I only found a very minute (1/4 teaspoon) of a weep in a spot where the reversing gear housing meets the oil pan. it was pretty high up near the fuel pump though so it cold be just some heated residue that i didnt clean up. Regardless... it wasn't the culprit. I dont know if that means that the failure point required longer operation, or if it means I fixed the problem. Only time will tell.

When I checked the oil, I had the same I amount I started with. So that's good. It was blacker than I'd like, but I'll take.

I am heading out on a 100mile crossing tomorrow and will likely have to motor a bit. I will let you all know how it goes under longer operation. But so far so good.

Very Good Jason. Shut the engine down every 2 hrs and check your oil during the trip. Once the engine works hard it starts to use a tad...it will be less with the 15w40, but you still have to watch it. Ensure you have lots of oil with you. If motor sailing ensure the level doesn't drop and top up as necessary. See if there is any change with the leak pattern you observed when motor sailing as well.

The oil looks blacker because it has more detergent and cleans the engine...with your 30 hr oil changes you will find that, after a while, the oil doesn't look much different on removal than when it went in. Took mine about a year to notice it clean changing at 20-25 hr intervals.

I have a feeling the ball inside your oil adjustment is sticking or gunged up. Something is wrong there because the changes you have made should have made a difference on start up and idle pressure. When you get a chance you should remove it and clean it up. I think you said you did that. Need to ensure no paint or rust on the threads when the nut backs off...that nut should turn with your fingers until you lock it onto the block once you have set the pressure where you want it. If no progress from there I'd call Ken at MMI and order a new one...the old version are supposed to be the best.

I haven't see one A4 out there that hasn't used oil when used hard. Always a constant vigil on oil in these older designed engines. Check oil everytime you get on the boat and every 2 hrs underway. The switch to 15w40 will eliminate allot of oil consumption but you still need to check it. I can run mine 5-6 hrs at low rpm and doesn't use...once I get into a sea and have to use a few more HP I can be guaranteed to add after 5-6 hrs...might only be a pint, but it is what it is.

[sailingchance]

Gotchya

Very Good Jason. Shut the engine down every 2 hrs and check your oil during the trip. Once the engine works hard it starts to use a tad...it will be less with the 15w40, but you still have to watch it. Ensure you have lots of oil with you. If motor sailing ensure the level doesn't drop and top up as necessary. See if there is any change with the leak pattern you observed when motor sailing as well.

The oil looks blacker because it has more detergent and cleans the engine...with your 30 hr oil changes you will find that, after a while, the oil doesn't look much different on removal than when it went in. Took mine about a year to notice it clean changing at 20-25 hr intervals.

I have a feeling the ball inside your oil adjustment is sticking or gunged up. Something is wrong there because the changes you have made should have made a difference on start up and idle pressure. When you get a chance you should remove it and clean it up. I think you said you did that. Need to ensure no paint or rust on the threads when the nut backs off...that nut should turn with your fingers until you lock it onto the block once you have set the pressure where you want it. If no progress from there I'd call Ken at MMI and order a new one...the old version are supposed to be the best.

I haven't see one A4 out there that hasn't used oil when used hard. Always a constant vigil on oil in these older designed engines. Check oil everytime you get on the boat and every 2 hrs underway. The switch to 15w40 will eliminate allot of oil consumption but you still need to check it. I can run mine 5-6 hrs at low rpm and doesn't use...once I get into a sea and have to use a few more HP I can be guaranteed to add after 5-6 hrs...might only be a pint, but it is what it is.

Thanks Mo! I plan to keep a very close eye on it. I was lucky she didnt seize when she dropped to zero before. Two hour intervals sounds about right. When I get to GT, I plan to pull the engine all the way out to get to the stuffing box. When I do that, I will take a good hard look at the oil pressure relief valve again and clean it up if need be. I have several parts I plan to order from ken when I get back to the states - including a new reversing gear cover. That will likely be on the list as well.

Thanks again for help and for all the fast responses. It means alot considering I get spotty internet and am hundreds of miles from any real help.

Cheers!

[Mo]

No worries....safe travels.

[Marian Claire]

SC. Glad to hear that the oil leak may be contained/slowed. A 1.5 turn in on the oil pressure adjustment should have made a big difference in your oil pressure. Sounds like it made no difference after some warm up even with the higher viscosity oil. My mechanically inclined grading contractor told me "pressure is pressure" 10/30, 15/40, water, air it matters not.
Do you have a magnet aboard? It makes extracting the oil pressure assembly easier. I am assuming you have the cone type normal in an early A-4.
My normal start up oil PSI is 60 and it slowly drops to 38 to 40 after warm up, one to two hours, at cruising 2000 RPM and 20+ at idle. The only time it drops below this "norm" is when the adjustment is not working correctly and I have to clean/dress it. If you have access it is a fairly straight forward task.
Only exception to this was when I had a pin hole in the line to the oil pressure gauge. But that PSI drop was fast. Dan S/V Marian Claire

[geekeasy]

My normal start up oil PSI is 60 and it slowly drops to 38 to 40 after warm up, one to two hours, at cruising 2000 RPM and 20+ at idle.

I'm having the same problem as the original poster. My engine settles at 40 PSI right after it starts up. Then sometime later it drops down to 20.

It sounds like I should follow your example and tighten the oil pressure adjustment screw such that it starts at 60. Does that sound like a reasonable approach?

Also... unlike the original poster, my water temperature goes up when the pressure drops. My engine which already runs hot starts running very hot, so I've been dropping the throttle which lowers the temperature, but does not seem to further lower the pressure.