What if....Overheat

[shrew]

I had to laugh as I started this thread because this happened to a friend of mine. However, the story is just embarrassing enough that I'm sure you're all thinking "A friend of your's, eh Shrew?". Kind of like the kid in Jr High who claims to have a girlfriend you've never seen "Because she lives in Canada....ya, that's it. That's the ticket. She Canadian" (A la John Lovitz).

So a buddy bought a new boat and he's very green, however, he's a bright guy and tries to do his homework. He decided to replace the impellors on his Volvo 5.7's. Apparently, he forgot to reattach or tighten an intake hose.

He overheated his Raw Water Cooled engines to the point that he started baking the paint on the manifolds and risers. When we opened the engine hatch you could hear the steam in the manifolds and risers.

This Volvo has a one-piece aluminum manifold, riser, and elbow. They also have these plastic plugs that look like either casting holes or freeze plugs. They all melted, included his sensors.

I'm curious what additional damage could have been done. My thoughts are:

1) burned out the rings
2) burned out, or tuliped the valves
3) warped the head
4) compromised the head gasket.

I'm curious what some of the mechanics and mechanically inclined think.

Again, no it's not me. It's for a friend. LOL!!!

[Gugi47]

Good for toaster from now....Never check the gages? Wow...

[mmwjr]

shrew what year is this boat and engines? The Volvos I am familiar with use a crank driven raw water pump and one only needs to remove the front cover to replace the impeller. These impellers are easier to install as the vanes can be folded must easier than the Bravos. Therefore no need to remove any hoses.

Since the hose was off I am assuming the seacock was closed as well.

I don't think 1 and 2 occurred but 3 and 4 are definite possibilities.

Tell your friend to replace the impeller and damaged exhaust components. Then run the engine till it gets to operating temps to see if any overheating occurs. If all good take temps with an IR temp sensor and if these look good perform a compression test. If all this checks out ok use the boat but keep a check out for temps and water in the oil; I had a friend do the same and after a month of use after repairs the engine made milkshakes (oil/water).

[shrew]

Originally Posted by Gugi47

....Never check the gages? Wow...

This is why I sometimes had technically. (Weird for a computer engineer, right?) He doesn't have analog guages. He has a single LCD display. When teh engine goes into 'alarm' mode, the only thing on his display was "Warning, Engine Temp. Reduce Speed or shutdown". At that point, I would simply shut down the engine. I wouldn't care whether it was 200F or 225F.

Again, he's a greenhorn.

[shrew]

Mike,

I've been harping on him to do an oil change and inspect the oil. He ran it for 20 minutes and was celebrating. The first thing I asked..."Did you check oil levels?". His face sank.

We did a trip this weekend. He said the engine ran great and temps were great for the 28-mile run. I said "Great!! Did you check oil levels when you got here to see if you 'grew' any oil during the trip?" Again his face sank and he asked me if I thought that was necessary. LOL!!

[jrsick]

Originally Posted by mmwjr

shrew what year is this boat and engines? The Volvos I am familiar with use a crank driven raw water pump and one only needs to remove the front cover to replace the impeller. These impellers are easier to install as the vanes can be folded must easier than the Bravos. Therefore no need to remove any hoses.

Since the hose was off I am assuming the seacock was closed as well.

I don't think 1 and 2 occurred but 3 and 4 are definite possibilities.

Tell your friend to replace the impeller and damaged exhaust components. Then run the engine till it gets to operating temps to see if any overheating occurs. If all good take temps with an IR temp sensor and if these look good perform a compression test. If all this checks out ok use the boat but keep a check out for temps and water in the oil; I had a friend do the same and after a month of use after repairs the engine made milkshakes (oil/water).

Mike, did you ever hear the cause of the milkshake? Maybe cracked manifolds or burnt flappers? I just had overheat myself and want to make sure I'm checking for secondaries.

[Gugi47]

Originally Posted by jrsick

Mike, did you ever hear the cause of the milkshake? Maybe cracked manifolds or burnt flappers? I just had overheat myself and want to make sure I'm checking for secondaries.

Most common are from, head gaskets, warp heads from over heat, but can be from many other to. Like exhaust manifolds gaskets.
Wait for Mike suggestion to.

[mmwjr]

Originally Posted by Gugi47

Most common are from, head gaskets, warp heads from over heat, but can be from many other to. Like exhaust manifolds gaskets.
Wait for Mike suggestion to.

You nailed it, for some reason the warped heads did not result in an immediate failure of the head gaskets but wasn't much long after.

[shrew]

This is what makes me wonder what the long term is going to be with raw water cooled, aluminum manifolds. He did remove and replace the manifold gaskets. The Volvo aLuminum manifold, riser, and elbow are one single cast piece.

[mmwjr]

Originally Posted by shrew

This is what makes me wonder what the long term is going to be with raw water cooled, aluminum manifolds. He did remove and replace the manifold gaskets. The Volvo aLuminum manifold, riser, and elbow are one single cast piece.

Time will tell, keep us posted.

[Overboard]

Originally Posted by shrew

This is what makes me wonder what the long term is going to be with raw water cooled, aluminum manifolds. He did remove and replace the manifold gaskets. The Volvo aLuminum manifold, riser, and elbow are one single cast piece.

Hey Shrew, any new developments in your buddy’s overheat? Has it kept running good for him?


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[shrew]

We'll see when he does an oil change in the fall.