overheating, water in hull, 0* on temp guage

remia99

Cadet
Joined
Sep 12, 2009
Messages
8
Newie here...

I just bought an '89 Regal Sebring w/ 4.3 Merc I/O. The previous owner tells me he bought it used with a new engine 3 years ago. He reported that when he bought it, it was overheating and he found unusual amounts of water in the hull... his mechanic found that the "water pump was cracked" as it was not replaced at the time of the engine replacement (suspected cause for replacement is improper winterization). It's now two years later and on my maden voyage... I have the same symptoms. My temp guage doesn't budge. I put the volt meter on the guage this evening, and I get 16volts-ish.

Where do I start looking?
 

Bifflefan

Commander
Joined
May 27, 2009
Messages
2,933
Re: overheating, water in hull, 0* on temp guage

Welcome to iboats.

Does it over heat on the muffs?
If not then its probably the impeller.
If so then,,,, well there are a number of things.
 

alldodge

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Mar 8, 2009
Messages
42,690
Re: overheating, water in hull, 0* on temp guage

At the engine is the wire connected to the sender, should be close to or on the thermostate housing? If yes, disconnect both ends of the wire at the meter and the sender. Set your meter to ohms and check to see how much resistance there is in the wire. If you get more then a few ohms the wire or connectors are corroded and need to be cleaned. Measure the resistance between the top stud of the sender and the engine block, if you get nothing take it out and place in a pan on the stove and heat it up. After it starts to boil measure the bottom to the top of the sender (take it out of pan with pliers), you should see a few ohms to 0-ohms depending on how hot it is.
 

remia99

Cadet
Joined
Sep 12, 2009
Messages
8
Re: overheating, water in hull, 0* on temp guage

I'll check that in the morning.

When on the lake at idle speed it ran fine for hours... still nothing on the temp guage, but at least by the lack of smell, so I assume it was okay. With some throttle though, it's quick to give me some smell.
 

alldodge

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Re: overheating, water in hull, 0* on temp guage

I'll check that in the morning.

When on the lake at idle speed it ran fine for hours... still nothing on the temp guage, but at least by the lack of smell, so I assume it was okay. With some throttle though, it's quick to give me some smell.

It runs fine for hours at idle, does this boat use an Alpha drive? If so might need to check the impeller in the lower housing. When it's idleing it sets low in the water and the pump in the outdrive doesn't need to work much at all to get water to the engine, when you pick up speed the boat comes out of the water and now the pump needs to work or it over heats.

Good luck
 

remia99

Cadet
Joined
Sep 12, 2009
Messages
8
Re: overheating, water in hull, 0* on temp guage

Yes, it has the Alpha drive.

Thanks for the quick replies!
 

remia99

Cadet
Joined
Sep 12, 2009
Messages
8
Re: overheating, water in hull, 0* on temp guage

I'm suspecting an impeller problem.. here's why...
When hooked up to the muffs, I disconnect the water inlet hose at thermostat housing momentarily to see the flow. It's definately not a steady stream, it's more of an intermittent burping (kinda like someone who was just given CPR by a lifeguard).

So, does this suggest line blockage, pump or impeller failure? Or is this to be expected when running on the muffs?
 

Bondo

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Apr 17, 2002
Messages
71,132
Re: overheating, water in hull, 0* on temp guage

So, does this suggest line blockage, pump or impeller failure? Or is this to be expected when running on the muffs?

Ayuh,.... Anytime there's an Overheat issue,... The Impeller is the 1st place to Look....

Yes,.. That's also the 1st place You should be lookin'...
 

scutly

Petty Officer 1st Class
Joined
Aug 20, 2009
Messages
368
Re: overheating, water in hull, 0* on temp guage

I'm suspecting an impeller problem.. here's why...
When hooked up to the muffs, I disconnect the water inlet hose at thermostat housing momentarily to see the flow. It's definately not a steady stream, it's more of an intermittent burping (kinda like someone who was just given CPR by a lifeguard).

So, does this suggest line blockage, pump or impeller failure? Or is this to be expected when running on the muffs?

at idle in the water i checked the water flow from the inlet hose and it was a constant flow but only about a 2" crown out the top of the hose. i was told buy the guy docked next to me that that was plenty. i read on these forums that it should be 5-6 inches. well i changed out the impeller and sure enough i get like 6 inches of water before it crowns. i like to call the guy next to me 3 engine joe. well he blew up another motor last week and pulled his boat out for the season.
 

remia99

Cadet
Joined
Sep 12, 2009
Messages
8
Re: overheating, water in hull, 0* on temp guage

Well, the impeller looks good (although it was in as snug as a ....).

The water hose coming out of the pump is malformed at the top, which I think killed any pressure that was trying to build. The mechanic who was representing the seller is sending down a whole new water pump assembly.

I should have it back together tomorrow... crossing my fingers.
 

sdoomaha

Petty Officer 3rd Class
Joined
Oct 6, 2008
Messages
94
Re: overheating, water in hull, 0* on temp guage

Sounds like you are getting your hands around the overheating issue.

Re temp guage - after testing the sending unit and temp gauge, if still not registering temp, do yourself a favor and check your thermostat. The temp sending unit is on the housing outside the thermostat....if the thermo is stuck closed, no water that is circulating in the engine is ever making it to the temp sending unit. Your gauge may be showing it is running really cool (only a slight change from the heat being transferred through the metal of the housing) when in reality you are runing much hotter.

Good Luck.
 
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