4-Beep Oil(?) Alarm

Ever since I've had my 1998 Promax 300 on my bass boat, which I bought new, every once in a long while, after towing a couple of hours to a lake, upon startup I'd get the 4 beeps, even though it would initially smoke like hell, as usual. The beeping, and smoke, would go away shortly. I attributed it over the years to the engine being tilted up and bouncing all over the road back from a trip, sitting in my garage for a few weeks, then bouncing around again to another lake. It would go many trips without beeping, sometimes years.

3 trips ago, it beeped upon startup. After a couple of runs the beeping stopped, as has been common.

Before the next trip, I topped up the oil in my 2 gallon reserve tank, even though it was already a little over half full. Looked at the engine-mounted reservoir, and it was 2" or so from full, as it's always been. Looked at the 1/4" clear hose at bottom of engine-mounted tank and it's full with no bubbles. No beeping at all on that trip, not even on startup. Boat run was quite short and easy, to the tune of about 12 gallons of gas the entire day, because we were on fish from the very first stop.

This past Wednesday, after driving over a couple of hours to a lake, it beeped upon startup. Smoked like hell, as usual. Even after turning it off and back on several times, it beeped on a 12 mile run. 6 hours later, on the 12 mile run back, it beeped. Took the engine cover off, looked at everything again, and all looked fine.

Could it be the sensor? If so, how do I test that it? Anything else I should look for?

Thank you.

99% sure the onboard oil tank is supposed to be full. Not 2" from the top. The oil warning for that is 4 beeps every few minutes.

Full... like up into the neck of the tank. :cheers:

Thank you guys for responding so quickly. So, do I just remove the engine-mounted tank cap and fill it there?

Also, will the system beep if the motor is not running and that tank is low, or does the motor have to be running? I am asking so I know what to do to see if the beeping stops after filling that tank.

Pull the cap on the engine tank, run the engine. if it fills up then replace cap. If it won't fill fairly quickly, the check valve on the air pressure hose (star lower part of the engine) is bad.

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Originally Posted by XstreamVking

Pull the cap on the engine tank, run the engine. if it fills up then replace cap. If it won't fill fairly quickly, the check valve on the air pressure hose (star lower part of the engine) is bad.

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Just so I am clear:

Because of what I described, and the fact that the engine tank has pretty much always been 2" low, it's possible that I might just need to bleed it, correct? I assume the procedure you describe is how to bleed the system, so when you said if it starts to fill up, "replace" the cap, you meant to simply put it back on, not get a new one, correct?

Also, I was actually wondering if there was a filter or something that might need looking at, but since the engine tank has oil that means nothing must be blocking the oil path from the remote tank clogged, right?

Thank you.

Yes, just put the cap back on (securely so it doesn't leak under pressure).

It should beep with the key "on" but engine "off" if the tank is low... also there is a "buffer" (timer) built into the system so it will take maybe a minute or two after the tank goes low or you turn the key on with the tank low, for the buzzer to actually go off.

Also, the excessive smoking at start-up could be oil in the boats main tank getting pushed back into the engine by the residual air pressure and a non functioning check valve after shut down. The valves clog and fail often since they lie at the bottom of the crankcase. Easy fix.

You have all been so helpful in helping me understand how the system works, and providing such informative insight. Thank you for that.

I forgot to mention this, but when I said I inspected the engine tank level, I looked at it with the engine off. My question here is, should the level in the engine tank be the same whether on our off? If, when I go try the bleed procedure, it fills quickly and is full when running, but the level drops when off, is that indicative of a problem or is that normal? I would think, based on the info you've all provided, the level should always be full, but just thought I'd ask, to be sure.

Also, during my inspection, i noticed the engine tank cap is on so tight I'm thinking i might end up needing to use channel locks to unscrew it. Of course, I will try wearing rubber gloves first. Or, do any of you have any tips in this regard?

You should be able to bleed the tank by just loosening the cap. It takes about a minute to build pressure in the remote tank before the on board tank will fill up. If the level drops after you shut it off, you have a leak.

It should stay full.

Somebody tightened the one on my brother-in-law's boat so tight that it cracked the tank up by the filler neck... so the tank would leak down to the crack below the neck and he had oil leaking down the sides of the intake.

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Originally Posted by skialot2

You should be able to bleed the tank by just loosening the cap. It takes about a minute to build pressure in the remote tank before the on board tank will fill up. If the level drops after you shut it off, you have a leak.

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I remember at the dealership when I bought it in 1998 that they said not to touch the engine tank cap because it needs to be tight and you don't want to tear the gasket. When you fill oil, fill the remote tank. So, that's what I've done over the years. I had it professionally serving e for many years, but sure if they ever loosened that cap. So, I am very concerned about loosing it if it hasn't been opened in all these years, and that it's so tight I might ruin the gasket. If that happens where do I get a replacement gasket? No one wants to service my engine near me, and parts seem to be far and few between out here. Can I make a gasket out of something, if need be? Of course, all this is moot until I look at it today or tomorrow.

Quote:

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Originally Posted by XstreamVking

Also, the excessive smoking at start-up could be oil in the boats main tank getting pushed back into the engine by the residual air pressure and a non functioning check valve after shut down. The valves clog and fail often since they lie at the bottom of the crankcase. Easy fix.

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Where do you get those? Parts for this motor are hard to find local to me. Will look at motor today or tomorrow, but is it a simple thread out, thread in?

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Originally Posted by David - WI

It should stay full.

Somebody tightened the one on my brother-in-law's boat so tight that it cracked the tank up by the filler neck... so the tank would leak down to the crack below the neck and he had oil leaking down the sides of the intake.

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Thankfully, it doesn'took like that's the issue for me, but I will be careful with that tank and cap.

Most merc dealers will have them. Boats . net is also a good place to look parts up online. Just look by serial number and part type. I think you may need part # 7 off this diagram. https://www.boats.net/catalog/mercur...ck-and-end-cap CHECK VALVE
Part #432783 is what I come up with. 33 bucks or so But do a search with your serial number and double check. Pull yours and try and blow back thru it. It should only go one way.

If it was the check valve, I would think the tank would leak down further when it sat longer?
With the crack in the tank it only leaked down to the crack, regardless of long it sat.

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Originally Posted by Basnova

I remember at the dealership when I bought it in 1998 that they said not to touch the engine tank cap because it needs to be tight and you don't want to tear the gasket. When you fill oil, fill the remote tank. So, that's what I've done over the years. I had it professionally serving e for many years, but sure if they ever loosened that cap. So, I am very concerned about loosing it if it hasn't been opened in all these years, and that it's so tight I might ruin the gasket. If that happens where do I get a replacement gasket? No one wants to service my engine near me, and parts seem to be far and few between out here. Can I make a gasket out of something, if need be? Of course, all this is moot until I look at it today or tomorrow.

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I think it's a rubber gasket. It should be fine. But if not, the gasket part number is 27-42999T It is available just about anywhere. I like the parts catalog at Mercurymarine.com it gives you all the superseded part numbers too.



Amazon.com: Jetunit 27-42999T Oil Tank O-RING for Mercury Mariner Outboard Oil Reservoir Level Cap Gasket 25-11332 Sportjet 105/135/140/150/175/200/225/250/275HP DFI EFI JET : Automotive

Attachment 544128

Could be several things. Got to give it a good check visually for oil leaks. Follow the lines etc.

Quote:

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Originally Posted by skialot2

I think it's a rubber gasket. It should be fine. But if not, the gasket part number is 27-42999T It is available just about anywhere. I like the parts catalog at Mercurymarine.com it gives you all the superseded part numbers too.



Amazon.com: Jetunit 27-42999T Oil Tank O-RING for Mercury Mariner Outboard Oil Reservoir Level Cap Gasket 25-11332 Sportjet 105/135/140/150/175/200/225/250/275HP DFI EFI JET : Automotive

Attachment 544128

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This is all excellent information for me. Thank you. Just so I know, looks like there is no screen or filter on the remote tank pickup hose, correct?

I'm going to be looking at it right after breakfast, here in California. My thoughts are to:

1) Eyeball everything when cold, to see if I can see anything obvious.
2) Start it and look at the engine tank to see if I see oil going into it.
3) Stop engine and ensure I can loosen the engine tank cap, then snug it back up.
4) Start engine, loosen cap, and watch for oil to fill tank. If it does, tighten cap.
5) Turn off engine and observe oil level to see if it drops.

If tank does not fill in step 4, at that point I should remove check valve to see it I can blow through it one way, correct?

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Originally Posted by David - WI

If it was the check valve, I would think the tank would leak down further when it sat longer?
With the crack in the tank it only leaked down to the crack, regardless of long it sat.

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OK, I will look at level before I do anything, to see if I can determine if it's lower than when I last looked at it.

Do you think it's possible that it's always had a little air in the system since the very beginning, hence why it's randomly thrown beeps since 1998? And, maybe I only need to be bleed, or is that wishful thinking?

I would've thought that one of the service shops would have said something when performing routine maintenance and such, but maybe not.

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Originally Posted by Basnova

This is all excellent information for me. Thank you. Just so I know, looks like there is no screen or filter on the remote tank pickup hose, correct?

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#34 is the remote tank screen, If I remember correctly there is a check valve on the side of the motor that pressurizes the in boat oil tank (air pressure forces oil into the motor oil tank)

It's been a while for me on the 3 litres but your rich condition after sitting could be a leaking check valve in the vapor canister! (I'm assuming the oil pump pressurizes the oil into the canister, and maybe at shut down, the pressurized oil in the boat tank is finding its way into the canister, lowering the oil level and causing the rich mix) My $.02

There is a screen at the bottom of the pickup tube in the remote tank. #34. Part# 32-99802

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Originally Posted by Basnova

OK, I will look at level before I do anything, to see if I can determine if it's lower than when I last looked at it.

Do you think it's possible that it's always had a little air in the system since the very beginning, hence why it's randomly thrown beeps since 1998? And, maybe I only need to be bleed, or is that wishful thinking?

I would've thought that one of the service shops would have said something when performing routine maintenance and such, but maybe not.

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I don't think so, and yes any halfway competent mechanic would see the level down and look into it... but they probably just bled the air out and super-tightened the cap for you. :rolleyes:

I have two 3 liter EFI's and four 3 litre opti's that I own. The check valves have always been #1 problem child for me. 2nd thing would be the float in the tank on the engine failing. # 3 is the 90 deg check valve fitting where the oil hose connects to the tank on the port side of the engine leaking. (easy to see leak) Have only had 1 in boat tank crack in 20 yrs. jm 2cts...

i had the beeping thing going on, i was cleaning the remote tank[soap/water] where the lanyard attaches, invisible cracks showed bubbles, new cap problem solved..

Quote:

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Originally Posted by skialot2

Amazon.com: Jetunit 27-42999T Oil Tank O-RING for Mercury Mariner Outboard Oil Reservoir Level Cap Gasket 25-11332 Sportjet 105/135/140/150/175/200/225/250/275HP DFI EFI JET : Automotive

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Ok, checked it all out.

The only possible place it could have been leaking was at the barb connection at the bottom of the engine tank, where the clear hose is zip-tied. Not enough to even drip, but i could feel wet residue. I was able to move the hose up and down ever so slightly on the barb, but not enough to easily have the zip-tie slip down over the barb. Nevertheless, I replaced the zip-tie with the the type that has the curve on the connector, designed for hoses. The hose no longer moves up and down that teensy bit.

I measured how low the oil really was and it was 3" from the top of the engine tank. I, then, removed the cap on the engine tank. I remember the original dealer being pretty adamant that I don't ever remove that cap because the gasket could tear easily, so instead of just loosening it enough to bleed it, I decided to take it all the way off to inspect the gasket. Lo and behold, the gasket was torn right where the gasket goes under the lip on the cap. I removed the gasket from the cap and placed it on the tank to see where exactly that tear would be, and it was right on the outer edge of the neck. I took the gasket off the tank, and placed it back in the cap.

Leaving the cap off the engine tank, I started the motor and looked inside the tank. I could see oil being pushed up into the tank. I assume this means there is no air getting into via any other place in the system, otherwise it wouldn't be filling. I watched until it started filling up the neck. Don't know if this is correct or not, but while it was rising in the neck, but before it overflowed, I replaced the cap. With the cap on, I could not see any air in the neck. Please tell me if I did this wrong and should let it overflow, or if I should drain some.

Turned off the motor at the switch, then started it again. Let it run for several minutes, no beeping. Apparently, the sensor works. Rev'd it slightly, let it sit a few more minutes and shut it off. Tilted the motor up enough to get the oil level "leaning" on the cap, waited 10 minutes, checked tank and cap. Still full and no leakage. While I give it more time to see if it leaks at the cap or drops level, I came inside to post this.

Here's what I think:

I kind of wonder if the original dealer tore the gasket but didn't replace it because of where the tear was, and it wasn't leaking. That might explain why they were so sure to tell me specifically not to remove that cap. I know it's been 27 years, but I distinctly remember them telling me that the gasket tears easily, and "you don't want to do that!" They scared me, which is why I never removed it over all these years. Of course, this is just conjecture, but I think it's possible that the tear allows a tiny bit of air to bypass the seal. Over time, based on how long it sits, how much jostling while tilted depending upon far I tow the next time, pressure based on temps, etc., the air would take up space while the oil dropped and I would get the beeping until it ran long enough to fill the tank up enough to stop beeping. Because, after all, this has been going on over 27 years!

Now, me not touching that cap for 27 years, not even to snug it, perhaps after being compressed over all these years the gasket began to allow more air in through that tear, to the point where even though oil is being pushed into the tank, it's now competing with the air that's being sucked in. Just a theory, so, anyone, feel free to comment, even if to tell me I'm wrong. I don't mind. At this point, I'm just happy things seem to be working the way they are supposed be.

Based on my theory, I think I should replace that gasket. After all, even if it's not leaking oil, as I said, I think that a gasket that contiguously goes under a lip in the cap is designed that way for a reason. All this said, would you use this Jetunit gasket previously linked to above, or should I hunt down an OEM Mercury branded one?

Thanks again!

Quote:

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Originally Posted by KIRCHNER

i had the beeping thing going on, i was cleaning the remote tank[soap/water] where the lanyard attaches, invisible cracks showed bubbles, new cap problem solved..

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Was your engine tank still filling with the cracked cap? I would think not, correct?

If the motor tank cap/gasket leak, the tank will overfill and leak when the engine is running... just like if the cap is off. He was talking (I think) about the cap on the "remote" tank in the boat.

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Originally Posted by David - WI

If the motor tank cap/gasket leak, the tank will overfill and leak when the engine is running... just like if the cap is off. He was talking (I think) about the cap on the "remote" tank in the boat.

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I'm talking about a leak so small that oil won't pass but air will given enough time. That's why I should replace the compromised gasket. Or, are you suggesting that if oil isn't leaking out, leave the torn gasket as is?

You initially said, "Looked at the engine-mounted reservoir, and it was 2" or so from full, as it's always been."

If the cap/gasket was leaking air, the engine-mounted reservoir would fill to the top (or overfill) every time you ran the motor.

OK, well I ordered an OEM gasket anyway, and will put it in when it arrives. In the meantime, I am not scheduled to fish for at least another week, so in the meantime, I will keep the motor tilted just above the trim rams to see what happens, if anything, to the oil level, as well as monitor that cap for any leakage.

On another note, I have always stored the motor in this position because I didn't want to keep pressure on the rams. Is it ok to store the motor in the vertical position, which puts pressure on the rams?

I don't think it matters. Running, you have probably 1,000# - 2,000# of thrust (depending on the prop) at the prop... with maybe 2:1 leverage on the rams.

I trailer and store mine trimmed all the way down.

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Originally Posted by David - WI

You initially said, "Looked at the engine-mounted reservoir, and it was 2" or so from full, as it's always been."

If the cap/gasket was leaking air, the engine-mounted reservoir would fill to the top (or overfill) every time you ran the motor.

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I just re-read your post, and thinking I must've mis-interpreted it the first time I read it.

That said, well, if it's not leaking air, and you say it would've filled up the tank even if it was, why was it always 2-3" low? I mean, it filled up pretty quickly when I removed the cap. I do realize that this motor chows the gas and oil like there's no tomorrow, but there's no way it drinks the oil faster than it was filling, so I take it the fill speed is good. So, that, in combination with what you're saying, would indicate that it must always have been low, right? It's not leaking oil in any appreciable amount that would allow the oil tank level to drop into beeping range. One thing I did notice was that the fill tube was not nestled in the clips on the side of the tank. Does that mean anything? I know for a fact that it used to be in the clips, so I put it back upon first inspecting this morning.

Unless something is allowing it to drain back down the fill tube? Skialot2 mentioned a check valve on the starboard side, but I thought if it was bad it wouldn't allow the oil to fill at all. He did mention removing it and try blowing through it, and that it should only allow passage one way. Hmmm, I didn't make note of how low in the tank that filler is, but if it's at 3" below top, maybe that is the culprit. But, If it does allow passage both ways, would it still be able to fill the tank when the engine is running?

On that same vein, what happens if I try to unscrew that fitting (check valve?) at the block that the tank fill hose is connected to. Will oil come rushing out? And, does it have some sealant in those threads?

Thanks again.

I'm just guessing that a bad check valve would allow the engine-mounted tank to drain completely... say over the winter; but maybe the oil draining back adds pressure to the boat mounted tank and it stops???

I dunno. :confused:

Quote:

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Originally Posted by XstreamVking

Most merc dealers will have them. Boats . net is also a good place to look parts up online. Just look by serial number and part type. I think you may need part # 7 off this diagram. https://www.boats.net/catalog/mercur...ck-and-end-cap CHECK VALVE
Part #432783 is what I come up with. 33 bucks or so But do a search with your serial number and double check. Pull yours and try and blow back thru it. It should only go one way.

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My serial number goes right to what you linked to above, so thank you for that link. As you can tell, I've not pulled one before, but in case I end up having to test the check valve, I have some questions:

When I disconnect the hose from that connector, I'm thinking of sticking some kind of bolt or something into the hose to prevent oil spillage, but won't oil also come pouring out of the block through the valve? If so, any recommendations on what to do about it? And, what about when I remove the check valve? Will oil continue to come pouring out of the block, too?

As far as inserting it, or a new check valve, back in, do I need to use a thread sealant or something, is there an o-ring in the seat, or does it simply seal when the check valve seats in the block? Also, any idea how tight it should be?

Thanks again.

Quote:

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Originally Posted by David - WI

I'm just guessing that a bad check valve would allow the engine-mounted tank to drain completely... say over the winter; but maybe the oil draining back adds pressure to the boat mounted tank and it stops???

I dunno. :confused:

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The fill point on the engine tank is up high. So, once the oil drops below that point, wouldn't it not be able to continue draining? I wonder if the tank is specifically designed with a high fill point as a safeguard against the exact scenario we are talking about here.

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Originally Posted by XstreamVking

I have two 3 liter EFI's and four 3 litre opti's that I own. The check valves have always been #1 problem child for me. 2nd thing would be the float in the tank on the engine failing. # 3 is the 90 deg check valve fitting where the oil hose connects to the tank on the port side of the engine leaking. (easy to see leak) Have only had 1 in boat tank crack in 20 yrs. jm 2cts...

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When the check valves failed, did the engine tank drain all the way down, or to just below the point where oil enters up high on the tank?

If your engine oil tank filled quickly at idle, the check valve is probably good. The oil should not drain out of the engine tank under normal use. Now that it's full run it and check it next day just to see if the level stays full. If it does, you are good to go.

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Originally Posted by XstreamVking

If your engine oil tank filled quickly at idle, the check valve is probably good. The oil should not drain out of the engine tank under normal use. Now that it's full run it and check it next day just to see if the level stays full. If it does, you are good to go.

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I just checked it, and the level has dropped overnight to right below the point where the oil normally enters the tank. To be clear, I have the motor tilted 30 degrees or so, and the oil level now is right below where it would normally enter via the hose opening near the top of the tank. I'm going to check in the morning, but if the level stays where it is, it must be running back down into the remote tank.

Quote:

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Originally Posted by XstreamVking

I have two 3 liter EFI's and four 3 litre opti's that I own. The check valves have always been #1 problem child for me. 2nd thing would be the float in the tank on the engine failing. # 3 is the 90 deg check valve fitting where the oil hose connects to the tank on the port side of the engine leaking. (easy to see leak) Have only had 1 in boat tank crack in 20 yrs. jm 2cts...

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I can't tell, but is one of the functions of #3 you mentioned above back-flow prevention? That's the only thing that looks like it would prevent the oil in tank from running back out through that hose filler opening 3" from the top of the tank.