Volvo Penta 5.7 King Cobra Engine Cooling

[holbroos]

I have 1988 Bayliner Cierra Convertible with a Volvo Penta 5.7 King Cobra and need to know how to check if water is cooling engine. Is there steps to check to make sure water is going to the engine before I take it out on the water and overheats. At my first test start up it idled and ran fine for about 10min and the temp gauge went up to 175. When we cut the engine off it was making a weird sound near the engine, like water gurgling or something. So I just want to check and make sure its getting water correctly to the engine..Can someone please tell me what to check and how to check it?

 

[Bondo]

with a Volvo Penta 5.7 King Cobra

Ayuh,.... Welcome Aboard,.... There's No such thing as a Volvo, King Cobra,....

There's Volvos, 'n the King Cobra is an OMC drive,.....

So what, Exactly do ya really have,.....

What ever it is, change the raw water pump impeller if it ain't been done in the last year or two,....

 

[holbroos]

It doesn't have an impeller in it, it has a water pump on the engine like a 350 Chevrolet engine

 

[holbroos]

Im not really sure what its called then because some of my paperwork says vovo penta and some is omc ...I don't have a clue..my boyfriend says it looks like a 350 Chevrolet vortec engine...so any idea?

 

[Bondo]

It doesn't have an impeller in it, it has a water pump on the engine like a 350 Chevrolet engine

Ayuh,..... If it's a Volvo, there oughta be a crank driven, or belt driven raw water pump, with a rubber impeller in it, besides the circulatin' water pump on the front of the block, like most all 350 Chevys,...
If it's an OMC, it might have a motor driven raw water pump, Or a raw water pump in the drive,.....

We still have No idea what drive ya got,...
Got any pictures,..??
Host 'em at a photo site, 'n link 'em back here,...

 

[Lou C]

Post pics so we know what you have . It could be an OMC boat converted to a Volvo SX system.
When you ran the boat on land did you hook up water muffs and use s garden hose to provide cooling water to the engine? If not the gurgling noise was probably the exhaust manifolds starting to overheat. And you'd need to now replace the impeller to avoid overheating.
If you did use the water muffs, a test you can do is to find a quiet ramp somewhere and back the boat down the ramp (put the transom drain plug IN), and lower the drive in the water and start the engine. This is a more true test of the cooling system than the water muffs because it tests the ability of the impeller to pull in raw water.

 

[Lou C]

It doesn't have an impeller in it, it has a water pump on the engine like a 350 Chevrolet engine

It has to have some kind of impeller to pull in lake/sea water to cool the engine and exhaust manifolds. It is a rubber pump inside a housing mounted in the outdrive (OMC Cobra-upper gear housing, Merc Alpha-lower gear housing) or on the engine (all Volvos and Merc Bravo system). It is a wear item that must be changed about every 2 seasons.
The engine water pump that looks like an automotive pump just circulates the water through the engine; it is the impeller that pulls in seawater.

 

[holbroos]

No Title

here's the pics I took today

 

[holbroos]

Thank you guys for trying to help me, lord knows I need it!! lol

 

[Lou C]

OK what you have:
Chevy small block
Cobra out drive that has the impeller in the upper gear housing
It looks like an automotive distributor (because of the vaccum advance unit on the side). You need to replace that with a marine unit that is ignition protected otherwise there can be an explosion risk if the fuel sys leaks fuel vapors.
Pull the boat and clean all that growth off the drive and make sure there is no stuff growing in the water intakes on the lower unit...

I see nothing Volvo Penta there it looks all OMC Cobra to me...

 

[Bondo]

I see nothing Volvo Penta there it looks all OMC Cobra to me...

Ayuh,.... Great advice, as usual Lou,.... I'll move this to the OMC forum,.....

 

[holbroos]

k thanks guys...the only places I see Volvo penta is on both sides where it looks like exhaust hoses hook up and it has Volvo penta 3857402 & Volvo Penta Transom Assembly in the metal casting on the left side and Volvo Penta 3856270 in the metal casting on the right side...Does that make a difference with what you've said I need to do?

 

[Lou C]

It looks like someone replaced the OMC exhaust (the original OMC manifolds used a rear outlet not the center outlet; that changed with some of them after 1991 or so); that part is fine as long as the hoses fit right with the Y pipe.
What it says on the transom plate is very odd; can you get a better pic of that?
Regardless the shift linkage on the starboard side of the engine is for sure an OMC Cobra style linkage with the ESA switches, load sensing lever and 2 shift cables. Volvo Penta drives do not use an ESA system and have one cable from the remote shifter to the drive for gear shifting. The other odd thing is it appears to have a Holley carb (make SURE it's a marine carb) but with 2 cables on the port side. That is definitely not original to an 88 OMC either they came with Rochester carbs on the Chevy engines. It's possible some swapped out the original engine and replaced it with one rigged for a Volvo; or they just changed the carb and exhaust.
Also I can't tell for sure but it looks like there may be an electric fuel pump there as well that was not original; some newer engines do not have a provision for the old style mechanical pump.
Make sure that the carb, fuel pump, alternator, starter and distributor are all marine rated or else you could have multiple hazards there. The auto distributor I see there probably won't work with the OMC ESA system.
I think you need to get this to a good mechanic to straighten out the issues here for it to shift right and be safe.

But no the cooling system appears to be standard OMC....
Normal operating temps should be 160-175.