Oil Analysis Poor Sample

[Lou C]

What motor oil are you using?

 

[otteray]

What motor oil are you using?

 

[otteray]

Rotella T4 15W40 Diesel oil for the last 3 years.

 

[Lou C]

Well that oil should be good enough to protect the engine, but I guess the combination of the sodium from salt water and fuel dilution of the oil is what's showing in the oil analysis.
I'd do the clear hose test with the boat in the water next.

 

[otteray]

I'd do the clear hose test with the boat in the water next.

I agree that is a good project for me in the next day or so.

 

[otteray]

Well that oil should be good enough to protect the engine, but I guess the combination of the sodium from salt water and fuel dilution of the oil is what's showing in the oil analysis.
I'd do the clear hose test with the boat in the water next.

It has been too windy to go out, so I did the clear hose test from stat to exhaust manifold at idle; connecting the garden hose to the flushing hose on the engine, not the muffs on the outdrive.
At 2500 rpm in idle position, there were some steady bubbles, and at low idle (650-700 rpm) there were no bubbles.

 

[otteray]

At this point, I need to take a sea test and find out if the bubbles were from the garden hose hookup, or from the engine itself. 6 wind swells this week so not yet.

 

[Lou C]

Yep thinking back, I did this test even before I had the overheat, tested it in the water and I had bubbles. And, I was getting sodium in my oil report back in 2011, so the head gaskets were starting to leak then, but I didn't really put 2+2 together, or maybe figured that I'd wind up replacing the engine anyway. Knowing what I know now, the right move would have been to pull the cyl heads, inspect the sealing surfaces, and have the heads checked at a machine shop. Here in NY you can buy a set of reman heads for a 4.3 for approx $300 each, good marine gaskets are about $125 and at the same time I'd replace the cyl head bolts ($100). Doing that, will give your engine a new lease on life IMO.

 

[otteray]

Taking the boat out Monday.
Little swell or wind!
Will see what the fiber reinforced clear water line going from the thermostat to the exhaust manifold does. Going to be awkward having a fishing buddy hold open the engine cover a little bit with the wide throttle open.

 

[otteray]

Is it safe to leave the pvc reinforced clear tubing on for a few hours with the engine running, for bubble test at sea; or is that risking the tubing to fail.

 

[Lou C]

I think it would be ok just take a look at it make sure the clamps are tight

 

[otteray]

Well, as i walked out of the house this morning, on the way to test the boat issue, I noticed a couple big chunks of brake pad on the driveway. So first things first, I started a thread on that topic in the boat trailer section.

 

[otteray]

I think it would be ok just take a look at it make sure the clamps are tight

Brake pads replaced! So, took the boat out into the bay. No bubbles in clear hose while engine running under load. Caught a couple halibut, too.

 

[Lou C]

Great news now to figure out where else the water could have come from. Good fishing too!
2 possibilities are exhaust system & intake manifold

 

[otteray]

Great news now to figure out where else the water could have come from. Good fishing too!
2 possibilities are exhaust system & intake manifold

Exhaust Manifolds and risers are new last year, torqued to specs; oil level hasn't risen or gotten milky, sparkplugs look good. I think I will hold off on removing the intake manifold (no visible hairline cracks) and, for now, put another 20 hours on the boat then send another sample. I just have a feeling that I may have done a poor extraction sample. If it shows not so great again, then I'll proceed checking.
The ol' boat has other issues needing attention in the meantime.

 

[Lou C]

What you can do is take another sample toward the end of your season. To check the intake you don’t need to pull it; you can drain the water out of the block & remove the thermostat housing. Poke around in the area right under the stat and see if the cast iron there is solid or not. A rottted area there will put water right in the oil. Not cylinders like manifolds….