Help. Steam coming from engine compartment
 

Cruising along this am and my wife noticed steam. Stopped and saw that the fitting blew. What is it. Doesn't look hard to replace. Is it a sign of another issue? Thanks.

I believe that's part of a known issue with the Indmar cat motors. Can't tell from your pics but it looks like you are a candidate for a recall/update with longer dump hoses and new fittings. Is the fitting that blew out nylon or brass? If it's nylon, your motor never got the update.

It is all nylon. Do you know if I need to take it to the dealer to have it done?

It's a simple install if you're handy, I've done 6 or 7. I believe it was originally a warranty update. Kit consists of fittings, a couple molded hoses, and 10 or 12 feet of straight hose. Do a search over on the Malibu or MC boards you'll probably find a bunch of threads about it.

Same thing happened to me two summers ago. Both sides on mine went the same day. Ended up installing this

http://www.bakesonline.com/detail.aspx?ID=3433

And all new these

http://www.bakesonline.com/detail.aspx?ID=885

I read all of the threads but no one seems to know if this will be covered by indmar. If it is a covered repair I was thinking about just replacing the nylon elbow for $6 and get the rest done after the season is over.

Svn. How long did the upgrade take? What about brass fittings instead of the nylon ones?

I'd run to Home Depot and get brass elbows and slap it back together and go on.

It was an easy install ... maybe an hour? It's not recommended to use brass fittings inplace of nylon. Apparently it can lead to corrosion due to a metallurgic difference . It's stated in the description of those elbows on the bakes site

I'd use brass ones t get me through a weekend, but that's about it.

The brass has me lost. I put brass fittings in for my heater install and the heater core is brass. I'll need to google what it does with the two metals.

That's about the dumbest place indmar could have put a plastic elbow. With all the heat coming off the cats, that's the last place I would ever put a plastic fitting. Put a brass fitting in it and forget about it. It does absolutely nothing as far as corrosion goes.

How do you know this?

I was going to try and contact indmar for their thoughts on using brass and possibly the upgrade but I could not find any contact info on their website.

"EngineNut" on this forum works at Indmar.

You can replace the nylon fittings with brass if you want to. The thread is 1/2 NPT. You might also benefit from installing the replumb kit from Bakes mentioned above. Bakes probably also has the brass fittings, P/N 605104

thanks

I work on boats for a living. I see all different makes and models in various conditions daily. I've never seen a brass fitting cause any corrosion. MFGs do it in plastic to cut down on costs.

Brass and aluminum are NOT compatible metals in a marine environment. Google it . If you run brass fittings in those extcat manifolds, the manifolds will eventually begin to corrode

http://www.boats.com/reviews/keep-al...-in-the-marine

Aluminum is going to start corroding the minute water touches it in a marine environment. On a marine engine the exhaust manifolds and risers will always be wear items regardless if you have closed cooling or not. The newer manifolds yes last a lot longer than the cast iron manifolds, but they still have a constant flow of raw water flowing through them while the engine is running. You're never going to stop the electrolisis in a lake or ocean.

Sure but it will happen faster around an area where a dissimilar metal is touching it

I had a 2010 and after the second elbow failed, Indmar replaced all of them with brass. It was wild, every single one would have eventually failed. Heat + flow-rate do not mix with plastic.

Also, everyone talking about Galvanic Corrosion, I wouldn't worry about it much. Cast-iron and nickel, it can be an issue if conditions are right, but carbon steel and Brass. I wouldn't worry about it at all.

That's not always the case. If this was a fitting that was on the outside of the hull and in the water 24/7 then yes, but this fitting is not. I've seen 25+ year old brass fittings an an aluminum case on outboards that when we replace the fitting the threads and the inside of the case still looked like the day they were put in. I've also seen where an aluminum fitting in an aluminum gas tank both completely corroded away. This is something you're not going to see until 15+ years down the road.

This is not a carbon steel and brass scenario. It's aluminum and brass. Those extcat manifolds are aluminum