Engine oil color. MD7

[hpeer]

Had the boat laid up for quite a while. I changhhed oil shortly before layup. Now just took off on a trip.

I noticed the engine oil had a medium grey appearance. I dipped the stick a couple of times and it went away. I ran the engine for a bit the other day then checked the oil. Fine.

I ran the engine for an extended period yesterday, many hours over night. All is well. Just now, 12 hours after last operation, I checked oil again. Medium grey on stick.

Soooo,mi sticker it a few times and, all of a sudden, the grey goes away. Seems to be be just a bit in the tube? Does not seem to be making oil.

2 cylinder, sea water cooled, 13hp Volvo.

What do you think is up?

[tkeithlu]

You mean opaque grey? As in an oil-water emulsion? If so, where is the water coming from? Any chance of a bunch of condensation? Some other minor and correctable source? If not, it should be causing hair to rise on the back of your neck.

[Shawn67]

Originally Posted by hpeer

Had the boat laid up for quite a while. I changhhed oil shortly before layup. Now just took off on a trip.

I noticed the engine oil had a medium grey appearance. I dipped the stick a couple of times and it went away. I ran the engine for a bit the other day then checked the oil. Fine.

I ran the engine for an extended period yesterday, many hours over night. All is well. Just now, 12 hours after last operation, I checked oil again. Medium grey on stick.

Soooo,mi sticker it a few times and, all of a sudden, the grey goes away. Seems to be be just a bit in the tube? Does not seem to be making oil.

2 cylinder, sea water cooled, 13hp Volvo.

What do you think is up?

If you are getting water into your oil it is likely the raw water pump. There are two versions of that pump. Both have seals at the crankcase side and at the impeller side of the pump. The earlier version has tiny weep holes between the two seals. If the water pump side seal goes bad it is supposed to just let the water out the weep hole (which will rust the heck out of the inspection cover the water pump is mounted to). Sometimes the weep holes clog and the water ends up being forced through the second seal and into your crankcase.

The second later version of the pump (with ball bearings) had much larger openings between the two seals to prevent this from occurring.

Shawn

[tkeithlu]

Shawn67, thank you so much for that very informative and reasuring post. Not knowing the engine, the original had me concerned- if it were my engine, it would be very serious indeed.

[leftbrainstuff]

Typically grey or white creamy look indicates moisture.

Pressure test cooling system and check coolant level. If ok look for other source of moisture.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[hpeer]

Shawn,

Replaced water pump with ball bearing variety a few years ago.

I'll look at the oil again this morning and if any indication I'll do a change then see what develops. Maybe just some condensation. She sat about 18 months.

[hpeer]

I just checked the oil this morning. It's fine, no grey at all. I've only 25 hours on the change and need to move 50 miles to do any work so I think I'll just observe for a bit to see what happens.

One of life's little mysteries to keep us awake at night. If I let them have their way I'll never get any sleep.

[barnakiel]

I think you have water in the oil.

I think you want to open the small bolt under the bottom of the oil pan, drain ALL oil. Open the oil dipstick and the oil top cap. Remove the filter. Turn the engine by hand at least twenty times, wait, give it another twenty turns, wait.

The above is because MD7 'locks' quite some amt of oil somewhere in the works. Turning by hand and draining by the bottom bolt helps get all of it out.

Now you want to lock the oil pan bolt, place a new oil filter in, fill the engine with new oil. ETC.

Start, use some, watch the dipstick every time before and after use.

b.

[Compass790]

Dont know this particular engine but agree it's moisture causing the greyness. Does it have a crankcase breather? If so check that it's clear & working. I would have suspected condensation after a long layup if the level isnt changing but a bit surprising that you still have the problem after a few hours running. Leaking head gasket is another possibility. If the moisture is only in the dip tube most likely only condensation. If tappet cover easy to remove you could look at that as well to see if moisture up there.

[reed1v]

Yup. You got water. Congratulations. Oil turning gray or whitish means water is entering your system. Really not a good idea to keep running the engine until the source of the water is found and the problem fixed. Unless you like to buy a new engine.

[hpeer]

Thanks Barnikle, ill try to do that. Not sure I can reach that bolt.

But it will have to wait until I get to a dock somewhere. A day or two.

[k. michael marquardt]

Some Volvo-Penta engines do have an manually operated oil drain pump connected at the same fitting as the oil pan drain plug. Saves a lot of bended knuckles and dirty engine compartment.

But most important and before you start any oil change you have to find the source of your water entering the engine. Condensation does not provide that much moisture. If it's not the circulating pump you want to think of siphoning back exhaust cooling water.

[hpeer]

Ran engine 6 hours today, checked oil about 90 minutes after shut down. Looked normal. Will see what the morning brings.

Yard is about 50 miles away now. Be there Saturday. Perfect timing!

It's OK, by now we need a personal bottom job anyway. ��

[hpeer]

Ran engine 6 hours yesterday. Oil looked fine last night and this am. So maybe it was just condensation? I typically run the engine at 2,000rpm and the temp never gets much above 140/150. It's sea water cooler and they run cold. Maybe it just takes a long time to boil out at those low temps?

Still intend to do Barnikles super oil flush at next change which is soon.

[Compass790]

Yes certainly sounds like it was just condensation. Big relief for you :-) Was that under load the 6hrs running? Our sea water-cooled engines oil wont get hot unless it's loaded.