water in lower unit

[jp6]

I have a 1978 volvo penta AQ 280A engine with water in the lower unit(coffee like color oil). Would just like to Know what the possible ways water could get into the gear oil. Also when boat is in neutral and idling I can hear a kind of rattling noise somewhere in the gear housing. Seems like the top of the housing. Thank you

 

[Roady1]

Re: water in lower unit

jp6, I had the EXACT same problem just last week with my Merc 3.0 lower unit. Now I have no experience with your type of motor, but I presume that most lower units are designed the same way. <br /><br />As far as where the water is coming from, it could be several different places. The only way to know for sure is to have it pressure tested by a professional. They can pinpoint the exact spot and save you a lot of guesswork. Now the rattling noise I can say with pretty much certainty what that is. The water in your lower unit has caused the bearing in the vertical driveshaft to fail. When that happens, the pinon gear gets off-center and it just eats it up. As someone told me here, water does not lubricate and the first thing to fail is the bearings. If you want to confirm this is the problem, remove the top cover, and drain the oil. You should be able to see the gear set and any damage that has been done.<br /><br />I had a lot of metal in my oil, you may to. Run a magnet thru the drained oil to see if you pick up any. Even a small amount is no good. My automotive experience tells me that even if I replace the damaged gears and bearings, I still had metal go thru all the other bearings in the lower unit and given time, they will also fail. My only option is to purchase a rebuilt lower unit.<br /><br />Here are 2 pics so you can see exactly what broke on mine.<br /> Pic1 <br /> Pic2 <br /><br />Now please, don't take my reply as gospel. I am no boat mechanic. I just wanted to try and help because your problem was the exact same as mine last week. Good luck and please let me know how you make out.

 

[summit1]

Re: water in lower unit

What color should the gear oil be when it comes out? I drained my lwr unit out last night and the oil was real dark, but it was not 'milkshaky' or 'creamy' or swirley as I have seen a lot of people with water in the oil complain about. I put syn 75w-90 back in, and it was clearish gold color, quite different from what came out. Is something wrong when the oil comes out dark like that? The drain plug also had very small amount of metal on it, but a magnet didn't pull any more metal up when I put it in the old oil. Am I okay to roll?

 

[tommays]

Re: water in lower unit

the oil should come out very close to how it went in other than water there is nothing in a correctly running gearcase that should discolor the oil if it is changed on a regular basis<br /><br />if you have water in the oil besides the milky color you should be able to see some small beads of water which will be easy to see if you let some of the drained oil sit in a glass<br /> <br /><br />if the oil was not changed for long periods of time by other owners it may take a few oil changes<br />to flush out all the dirty oil<br /><br />i find that syn oil holds up much better and have found mercs gear lube to be better than any thing else i have tryed<br /><br />tommays

 

[summit1]

Re: water in lower unit

I called a few mech's (2 were merc certified) before your post Tommays, and they said the same. <br /><br />My mistake from their standpoint (and anyone else agree here???) is that I used Syn Castrol 75w-90, not Merc or some other outdrive lube to refill last night. All three said without hesitation to drain and refil with Merc or another outdrive lube before I take it on the water becasue I was about to ruin the outdrive with Castrol Syn. What does everyone think?

 

[summit1]

Re: water in lower unit

They also said to ditch the WIX oil filter I put on last night, because I would ruin the motor because it doesn't flow enough. I have read the oil filter study put on here, but I can only compare filter to filter, not the impact that the filter will have on the motor (if 8.4oz vs 10.8oz is enough flow). Several respected people on here use them (or NAPA) so I figured I'd run with it. I do run the boat pretty hard (pull skiers and like to WOT sometimes). Will I get enough flow, or am I doomed to change everything I did last night?

 

[tommays]

Re: water in lower unit

i have run a fram on my 3.0 for 9 years the boat is heavey 2800# and at least hafe of the hours were with about 800 # of crew and camping gear the motor is as good as the day it was made<br /><br />IMHP once you have oil pressure you dont need a huge flow on a stock engine i find that the fram keeps the oil very clean and free of particles that would cause motor ware <br /><br />a filter can pass 20 oz of oil but if its dirty how does that inprove engine life you can only flow a limited amount of oil through crank,rod and cam bearings if they are at the correct clearence i never have less than 40# of oil pressure unlesss im dead slow<br /><br />funny thing if your into motorcycles harley has just had a huge problem with filters that are not keeping the oil clean enough and causeing engine damage<br /><br />tommays

 

[summit1]

Re: water in lower unit

They are probably just trying to scare me into getting parts/supplies from them. Everyone I have talked to that doesn't sell boat supplies says similar things (just use a quality filter/oil, parts etc.), Tommays. I am just a pup and still learning, trying to do the right things for the boat. I appreciate your help on this and the other threads.

 

[Bondo]

Re: water in lower unit

My mistake from their standpoint (and anyone else agree here???) is that I used Syn Castrol 75w-90, not Merc or some other outdrive lube to refill last night. All three said without hesitation to drain and refil with Merc or another outdrive lube before I take it on the water becasue I was about to ruin the outdrive with Castrol Syn. What does everyone think?

BS.........<br />I run Either Valvoline Syn 75W-90,<br />Or<br />Mobil 1 Syn 75W-90.........<br />

They also said to ditch the WIX oil filter I put on last night, because I would ruin the motor because it doesn't flow enough.

Another BS.......<br />Wix is about the Best money can Buy.........<br />NAPA's are rebranded Wix filters......<br />

They are probably just trying to scare me into getting parts/supplies from them.

That, I Believe to be True..........<br />

I have a 1978 volvo penta AQ 280A engine with water in the lower unit(coffee like color oil). Would just like to Know what the possible ways water could get into the gear oil. Also when boat is in neutral and idling I can hear a kind of rattling noise somewhere in the gear housing. Seems like the top of the housing.

Sounds Serious.......<br />Any Seal can be Leaking.......<br />The Rattling doesn't sound Good......<br />Time for a Rebuild....??.......

 

[fastimz]

Re: water in lower unit

I have an Alpha one drive an I use the Castrol 75W -90 in my unit and I haven't had any problems and it comes out clean and isn't breaking down. Keep boating!!!

 

[jp6]

Re: water in lower unit

Thanks for the reply. I ran a magnet thru the oil and found no metal to speak of. Just got the boat this year with 300 original hours on it. Not sure when the last time the bellows, U-joints, or seals have been looked at. Could any of these be a source of a slight rattling noise in neutral at idle. It sounds like it comes from the area of the vent screw, just bellow it. Should my first step be to have it pressure tested? Thank you

 

[Roady1]

Re: water in lower unit

jp6, the pressure test will be something you need to do, but unit you fix the rattling noise, fixing the water leak won't do much good. As you inspect for the cause of the noise, you could just re-gasket the whole unit and kill two birds with one stone. just my 2 cents.