Mercruiser 5.7 EFI Water in Oil

[sarnone]

Hello to everyone is helping me solve my issue. I pulled my exhaust elbow for starters because of minerals and such at the joint. Noticed at least one bolt was loose. The gasket surface doesn’t look like a good seal and black exhaust dust appears to be traveling to the water ports. Looked straight down and a few ounces of water directly below. A tiny bit of water, just wet, aft in the exhaust manifold and no water forward. I used my snake camera and no signs of rust or anything just black on the walls and ports. The two bolts aft on the elbow have scale where the joint would be. My plan is to do the gaskets on both sides and make sure the surfaces are true. Run it, change the oil again and run it again.Any objections? Here are some pictures…
Thank you in advance for your support.
Steve

 

[alldodge]

I don't see an issue with the gaskets. The only possible sign of a leak goes to one of the bolts but that would not let water into the block

 

[flashback]

I see a crack in the elbow. The snout looks ok.

 

[alldodge]

I see a crack in the elbow. The snout looks ok.

I'm old, eyes not the best, where's the crack?

 

[flashback]

I'm old, eyes not the best, where's the crack?

Maybe just a crack in the paint but looks like a crack in the 3rd pic on the bottom of the elbow,

 

[alldodge]

Don't see it and zoomed in, but again my eyes are not as good as they once were

 

[sarnone]

All, The "crack" i think you are talking about is from the two halves of the casting from manufacturing.

steve

 

[Scott Danforth]

looks like a parting line in the casting.

however with water pooled in the bottom of the manifolds, I would file the surfaces flat, install new gaskets and run it for a run. if you still have moisture, get new manifolds.

 

[sarnone]

All, I am seeing exchange between water and exhaust. But, I am not an expert...lol. See pic...

Steve

 

[flashback]

This is what I saw, maybe nothing?

 

[sarnone]

This is what I saw, maybe nothing?

Yes, thanks. That is the parting line caused by the manufacturing process.
steve

 

[flashback]

Not too sure of that, look at the rust on the mani.

 

[alldodge]

If the elbow is cracked there the water will not enter the motor

Don't see an issue with the other gasket area because it seems to just be layers and gasket just separated when removed

my opinion

 

[flashback]

If the elbow is cracked there the water will not enter the motor

Don't see an issue with the other gasket area because it seems to just be layers and gasket just separated when removed

my opinion

I agree but what if the elbow has an internal crack?

 

[Scott06]

Maybe just a crack in the paint but looks like a crack in the 3rd pic on the bottom of the elbow,

Pretty sure that is a casting line

to op doesnt look like water is streaking down exhaust side. Think water in bottom came when you took it apart

 

[Lou C]

Not sure about the possible crack/casting parting line.
I would be cleaning the sealing surfaces up the best I could and trying it again, like Scott said.
BTW, my exhaust system used in salt almost 5 years now does not have that corrosion you see where the manifolds and elbows mate.
Since you were in freshwater, that might be just poor quality paint, hard to say.
Clean em up with a mill bastard file, check em with a straight edge and feeler gauges, use OE gaskets, follow their instructions to the letter.
PS did you drain em before you took em apart?

 

[sarnone]

Pretty sure that is a casting line

to op doesnt look like water is streaking down exhaust side. Think water in bottom came when you took it apart

Scott06, thank you. However, cooling system was fully drained before I took it apart. Also, there is a drain point directly below this location.

 

[tpenfield]

Not having read the entirety of the thread, but my initial thoughts were the gasket between the exhaust manifold and the riser/elbow.

I would do a cylinder leak test to rule out a head gasket and then do a maintenance iteration on the exhausts cleaning out the passages, prepping the mating surfaces, new gaskets, etc.

The other engine might need the same TLC as a preventative measure.

 

[sarnone]

Not having read the entirety of the thread, but my initial thoughts were the gasket between the exhaust manifold and the riser/elbow.

I would do a cylinder leak test to rule out a head gasket and then do a maintenance iteration on the exhausts cleaning out the passages, prepping the mating surfaces, new gaskets, etc.

The other engine might need the same TLC as a preventative measure.

Tpenfield, thanks you for the input. And the other engine did overheat from a busted belt for a moment about 4 years ago and I had to do the gaskets, boots and butterflies. So, that should be holding up okay for now.
I’m getting the impression during the tear down that this might be the original gasket and then of course it having a loose bolt and signs of water leakage on the outside as well as inside.
Sarnone

 

[Lou C]

When you install the gaskets keep in mind that proper torque is very important. I would use a thread chaser to clean the threads for the bolts that thread into the manifolds, and clean the threads on the bolts itself. Follow the manufacturer’s instructions about how to install the gaskets and use a torque wrench. Some need to be retightened after the initial warm up.
The ultimate solution (but very expensive) might be converting the wet exhaust you have to dry joint if you need to replace these. However properly installed you should be able to get then to seal with no leaks. Seeing as how you’re in freshwater if they pass the acetone test they should be ok.