Premature rust found on manifold and leaks at the nylon elbows

[blackout_58]

Hey guys, I need some advice. I went to summerize my 2011 21V and noticed there were 4 leaks at all of the nylon elbows. I also noticed rust on both undersides of the manifold. Should this be happening so soon in a freshwater only boat? Take a look at the images and let me know if anyone had seen this. I was told by my dealer that this was a wear item and wouldn't be covered by warranty.14047

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The engine is an indmar 5.7 325hp.

[CornRickey]

If water is leaking from between the riser and manifold then the gasket needs replacing. If it fails internally then you could have significant issues. The rust looks like the paint has been stripped off of the manifold. Possibly starter fluid? The leaks on the elbows are fixed by removing, applying Teflon tape the reinstalling

[blackout_58]

Thanks for the reply, two of the elbows cannot be reached without removing the riser due to design, trust me I've tried. I have replacement gaskets on order so hopefully I can resolve it this weekend. Any idea why this would occur so soon? Can you clarify what you mean by starter fluid?

[Kma4444]

The paint is missing on the exhaust manifold because that area is before the water jacket on the manifold. It's just from heat, no worries and it is absolutely nothing to worry about. Using some teflon tape on the elbows will correct the leakage there. Nothing too shocking there either, pipe threads are an abomination, they are also ubiquitous. Tape will seal them, until they start to weep again. The fact that they are plastic doesn't help either, but they are cheaper, lighter and will seal,,,, kinda,,, without any sealant on them when new. So that makes them quicker to install. Saves money, yadda yadda yadda.

[CJD]

You can hit the rust spot with high temp spray paint. Mine looked exactly the same. Part of my winterizing is to touch up anywhere the paint has chipped or burned like that. Even though it states doing that in the manual, I have yet to see a shop that does.

[blackout_58]

Thanks for all the feedback guys, I'll take a few photos on the steps to get those elbows taped and replaced as I verified one elbow as being moderately deformed after removed and would not go back in. The remaining two have such limited access that I'll have to raise the riser to get to them. I'll go ahead and replace the gaskets while in there and paint over the rust after a light sanding for cosmetic purposes using a high temp paint and hopefully be on the water by this weekend as Memphis in May begins.

[cadunkle]

I would replace those cheesy plastic fittings with brass. Use either teflon tape of a liquid thread sealant. Just wire wheel/brush the rust and put some hi temp engine paint on them to keep from getting all crusty.

[wotan2525]

I would replace those cheesy plastic fittings with brass. Use either teflon tape of a liquid thread sealant. Just wire wheel/brush the rust and put some hi temp engine paint on them to keep from getting all crusty.

This is exactly what I was going to post. The rust isn't really an issue and since these manifolds are so thick -- rust will actually protect them from further oxidation. This is why you can see old cars/trucks (pre 1950s) that are completely covered in rust but have not rusted through. Rust is a surface oxidation and does not continue on thicker materials. (Also think of railroad rails....) The reason "rust" is such a negative term these days is that modern cars have such thin sheet metal (to save weight and cost) that they rust all the way through and then it just keeps going.

[blackout_58]

Thanks for helping put my mind at rest guys. I'll be sure to get some before and after pictures.

[blackout_58]

Finally got the elbows in place last night and took her out for a run today with no leaks. It wasn't a complex job, but having to make your our Allen wrench was a little silly. I happily shared my customer opinion with indmar during our back and forth. Anyhow, here are a few pics:

Gaskets were a bear to remove....
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Another engine shot showing both sides.
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Up close shot of the inside of the manifold with the riser removed.
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[CJD]

Did you go with brass elbows? I assume they were just standard pipe thread?

[blackout_58]

I was going to, but after talking to customer service at indmar I decided against it. They basically said I would need to retap the holes and that just wasn't going to happen due to limited clearance. So far the Teflon tape is a legitimate fix as I didn't notice any leaks while out yesterday.