OH NO!!! Big BOO BOO!!!

[Condor1970]

I finally got my shift cable set to where it will work right, and got the engine up and running well. I got it to shift into forward and reverse without cutting out.

My neighbor had to work tonight, so I decided to hook up the muffs and fire it up to test myself.


Then after a few minutes I noticed the temperature was in the red.

I looked in the back, and the Muffs slipped off. AUUGGGHHHH!!!!!!

I have no idea how long they slipped off for. Maybe a minute or two.

When I put them back on, I noticed no water would come out of the two little exhaust ports on the bottom of the transom. Exhaust would only come out the prop, and it was hot.

The engine, thankfully, seems to run fine (hopefully Mobil 1 did its job), but what is the deal with my temperature?

Now what?!?!?!?!

 

[rmoreaux1]

You smoked your impeller. Time to get a new one. They can burn up after only a few seconds. Oil will not keep you from cracking a head if overheated too much.

 

[Condor1970]

I know, I think I got it shut down quick enough.

What I am wondering, and maybe you can tell me.

If the impeller was bad, shouldn't the garden hose still push water through the engine?

Why was no water coming out the exhaust?

 

[H20Rat]

I know, I think I got it shut down quick enough.

What I am wondering, and maybe you can tell me.

If the impeller was bad, shouldn't the garden hose still push water through the engine?

Why was no water coming out the exhaust?

When the cold water hit the really hot metal, it caused it to steam up which could actually temporarily cut off water flow. You get a pressure bubble and backflow.

Also, just a FYI but M1 is generally a pretty poor oil overall, ESPECIALLY in high temp/stress situations. M1 5w-30 in particular will sheer down to something close to water fairly quickly. MUCH better oils out there, even cheaper than M1. (rotella T6 is a very good oil for many applications)

 

[o'neal]

I know, I think I got it shut down quick enough.

What I am wondering, and maybe you can tell me.

If the impeller was bad, shouldn't the garden hose still push water through the engine?

Why was no water coming out the exhaust?

It dont take long to burn up the impeller and if it is toast you wont get water circulating through esp out the exhaust.

 

[Condor1970]

All I can do now is I just ordered another impeller of Amazon, and replace it.

I'm praying the engine is ok. I still had oil pressure when I shut it down, and within a couple minutes, the temp gauge dropped below the red.

The starter still rotates it fine, and it will start and run fine, so I think it is ok.

 

[ktbarrentine]

You had better check your exhaust shutters, too. Temp in the red will quickly melt them and they will fall off and go down the Y-pipe. Sorry......

 

[Condor1970]

Exhaust shutters? Are you kidding?

Can anything else make my day worse?

 

[stonyloam]

With no water flow out the exhaust the shutters will burn off pretty quickly. Yes your impeller it shot and probably your pump housing too, especially if it is an Alpha I witha a plastic housing. Any sign of heat damage to the housing, replace it, or better yet just replace it. When you change the impeller, it will be best to pull the entire drive and look to see if you have shutter pieces in the exhaust port.

 

[Bt Doctur]

Hope your getting a full pump kit, I`m sure the water pump base got scortched too

 

[NHGuy]

Well yeah, split the drive and inspect the entire water pump and housing, not just the impeller. Expect to do the kit, which is the impeller and the base gaskets that go beneath it. Check the pump housing and tube for any distortion. Do a pump if there's any remote possibility of trouble. Also look up inside the upper for the water pocket cover, if it got really hot that could have changed shape, but that's less likely. Lastly the rubber exhaust hoses to the outlet pipe can get melted if it was run too long without water.
Sorry to hear that happened.

 

[Condor1970]

The big exhaust hoses up top to the transom look good. Nothing melted I can see.

I ran a snake wire up the two little exhaust ports at the bottom of the drive. They were no obstructions on the way up into the main exhaust pipe. I didn't feel anything rattling around in side there either.

To get to the exhaust shutters, can I access them just removing the exhaust elbow on top of the engine and the rubber hose?

Isn't the shutters up there?

 

[theBrownskull]

That is where the flappers should be. I attached a link off of youtube for a reference point. This person is working on a 4.3.

 

[Condor1970]

Ah ok. So, they should be near the top of the exhaust, just below the top rubber hose, and not way down low on the second lwoer hose. Got it. Hoepfully, this won't be too bad replacing them. My biggest fear is pulling the lower tomorrow to see what happened to the pump.

DAGNABBIT!!!! I just changed that flippin' impeller too!!!!

One thing I now remember. When I was testing the forward and reverse drive, I did notice all of a sudden the exhaust coming out of the prop started smoking a bit. White smoke, I was like, "that's wierd", but everything still ran fine. A couple minutes later I noticed the high temp, and it dawned on me there was no more water coming out the exhaust or the propeller.

 

[pmill]

You might want to consider buying the oem muffs also, pinned on so they can't fall off.
Part # 91-44357q2

 

[Condor1970]

Ok, I got it apart.

YEP!!! It's toast. "Most" of the impeller was still there though. I found a lot of little pieces of rubber down in the intake, but don't really see anything in the upper water pipe. I hope I didn't shove any of those little pieces into the engine when I slipped the muffs back on with the water running. That could be bad. Although, from what came off, any pieces that may have made it into the engine, would probably pass through, as there are pretty small bits.

Now I need to pull the exhaust. Great!!

The issue with this exhaust, is I need to pull the elbow off the top of the manifold, because it has this nub sticking out that prevents you from just sliding the rubber hose it up, to get at the shutters below it.

I wonder if I can re-use that exhaust gasket...hmmmm.....

 

[Condor1970]

Ok, a quick update, and a little question from you guys who know part numbers better than I do. I looked everywhere for the right part number on the shutter, and of course they aren't numbered. Also the exhaust elbow gasket.

Anyway, this is everything I picked up off Amazon for my repairs.

I got the Sierra pump from Teleflex:

http://www.amazon.com/gp/product/B00144D09O/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

I picked up the 3-water hole gaskets for the exhaust elbow. Also Sierra.

http://www.amazon.com/gp/product/B000LN4ITA/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

And the real kicker..... is the exhaust shutter. The shutter has absolutely no damage at all. It is in almost perfect shape, with exception to a few tiny cracks in the rubber due to age, but not heat damage. I think I got lucky and didn't get my engine too hot. However, because the shutter is old, it was sagging a bit, and not staying sealed against the sides of the exhaust pipe simply due to gravity. So, I figured I might as well replace it, since I have it apart.

http://www.amazon.com/gp/product/B000N9LWKK/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

I am assuming this shutter and gaskets are the right ones, because they look identical, and the shape of this one looks like it will fit the 2-3/4" inner diameter of the exhaust pipe.

Anyway, if you guys see anything wrong with my order, let me know.

 

[slag]

When the cold water hit the really hot metal, it caused it to steam up which could actually temporarily cut off water flow. You get a pressure bubble and backflow.

Also, just a FYI but M1 is generally a pretty poor oil overall, ESPECIALLY in high temp/stress situations. M1 5w-30 in particular will sheer down to something close to water fairly quickly. MUCH better oils out there, even cheaper than M1. (rotella T6 is a very good oil for many applications)

Im curious as to why you say this. Can you post some documentation on mobil1 vs other oils? Every other oil analysis or oil blog usually lists mobil1 as being a pretty decent oil.

 

[gibbywmu2000]

Your engine will be fine. I've had mine overheat a few times (back when I was an inexperienced boat user, and I bought my boat). I had the impeller go a few times and one was out on the water. I was pretty stupid and limped it back home, and it got so hot that it burned right through my exhaust elbows..........and on the starboard side it even damaged my gel coat near the exhaust (my thru hull comes very close to the bottom of my swim platform). Was very nice work on my part......thankfully I never damaged the engine!