Clogges Exhaust Manifold of Therostat??

So I just replace the Impellar, Started the boat using a Fake a lake I noticed there is very little water coming out the Exhaust.

Then it starts to heat up, If Rev it up it seems to Cool down. I rev it up and water is coming out with steam

Also there seems to be alot of Steam coming out of the Exhaust and the manfoldsare much hot then I remember. I basicly burned my hand when i touch the top of one of them.


So I start pulling hoses. The hoses that go to the Bottom of the Exhaust manfold has alot of Brown scale in it??.

I cleaned that out.

The hose come from the Top doesn't seem to be Hot and there is no water in it ( or very little ) when I take it off.

So could the be a Clogged thermostat ( i hope) or a Clogged exhaust manafold??

Enginer is a 2008 5.7 Black Scorpion with 190 hours.


Any help would be better. suppose the be leaving for a trip next Tuesday


Chris
Any Ideas is some I can Take apart to Check??

I should ready read before I post that should say "Clogged Exhaust manifold or Thermostat"

I so I don't thin is it clogged Manafold I just ran water throught it just fine.


I put water hose on the the bottom inlet and it came out the Top if i plug the top it comes out the Exhaust ports, so I think that seems fine.

any guesses where the Thermastat is??

Chris

Do you have the new impellar veins angled the correct way?
Was the old impellar missing rubber, and stuck somewhere?

first of all soory about the Spelling I am very frustrated.

So I just pulled the Impellar to recheck and the vains are all going the Correct direction.

The old impeller had 80hours and looked Perfect.

This is the third impellar in this boat and I haven't destroyed one yet. So I there wouldn't be old peices stuck in there.

Chris

Start where you left off.
A few thoughts.

First, I dont give a rats behind what direction you install an impeller, in one rotation it has sorted itself out without damage. Enough of that..

Did you have a problem before changing the impeller?

To find a blockage, look for a hose that is hard or swollen from pressure while running.

Thermostats rarely give crap on these engines.

I/m thinking air leak at the pump from bad gasket seal, hose clamp, fake-lake issues etc. etc.

OK so it FIXED!!

Must have been a Airleak somewhere I disconnected and reconnected every hose then re- Tighted everything.

Hard to beleive that a Airleak could make such a bigger differance.

So one last Question is there anything I need to recheck or worry about becuase it got so hot the Alarm went off.??

thanks for the input glad I didn't start tearing out Therastats.


Chris

Chris-
As long as you shut her down went the alarm went off, I think you should be OK. A few things sound a little funny to me though about your problem. Were you drawing water out of a bucket while running, or was the garden hose connected directly to the cooling hose in the boat? I always connect directly to the hose on the pick-up side of the water strainer. In this case, an air leak would not have caused your problem as the pressure from the hose would have been pushing water through your system. I am not familiar with the Black Scorpion engine, but on every marine cooling system I have worked on, water is always flowing through the exhaust, regardless of the thermostat. The stat allows water into the block when it opens, when closed all the water flows out through the exhaust. In other words, the hose going to the front our your manifold should have water in it at all times. Also, for future reference, if you follow that hose from the manifold up, the other end should be somewhere very near the t-stat housing.

I hope it is fixed, but I would keep an eye on those manifolds and risers. They should never get so hot that they would burn your hand with a quick touch (actually you should be able to lay your hand on them for several seconds, again, not familiar with a Scorpion engine, but I am assuming the same holds true).

Chris, not familiar with the BS engine either, but I assume it is connected to a VD or DD. If that is the case you need to check the transmission cooler. Almost all of the over heating issues that I have heard about or experienced were either an impeller that went bad or a clogged trans cooler. It should be located on the strbd side of the engine and looks like a black sausage with 2 smaller hoses coming out of it. The easiest way to find it is to follow the output hose on the raw water pump until you hit the metal tube, it will be the first thing you find inline on the hose. Pull the hose off the bottom and finger or shop vac it out. Good luck

I had the Garden Hose hooked up to the Fake a lake.

The water didn't start coming out until the Engine until it Warmed up, then steam and Water started coming out.

I had added a can of Sea foam and thougth at first it was the Sea foam was causing the Steam. ( boat has sat in the Garage for the last 7 mo)

The boat is a Vdrive I think I found where the " Black Sausage" is but it is on the forward side of the Engine it has two smaller hoses coming out of it going forward. At little further down the system on Starboard side on the botttom of the engine is a Black Box with Metal Hoses coming out of it. I am Assuming this is the trans cooler?

I will Pull all these hoses next if it start to heat up again.

But last night after draining all the water and retighten every hose clamp. I started it and Water came out the Exhaust immediately and the Boat heated up to 160 and never moved, the Exhuast Raiser stayed cool to the Touch.

I let her run for about 5 mins no change in Temp, No Steam.

Now let hope it doesn't happen again at the lake.

Again thanks for everyones input.


Chris