Mercruiser 228 overheating?

[84Ed]

I have a 305 Chevy V8 with Mercruiser 228 set-up.<br />the problem is this: after boating all day, slow speed to dock, notice temp guage way up..it was night..just left. today....start engine..guage works up to 150...stays put. I undock cruise around at various speeds...temp guage within a few degrees of 150...so what problem you say...well, if I take a little water and drop it on the front of the intake manifold...it just sits in the little cast wells..not too hot...but if I drop water on the center of the intake manifold (across from the carbuerator), it sizzles and bubbles away...pretty hot!<br /><br />My question is: is this normal? can you have a normal temp guage reading and a too hot engine?<br /><br />I guess I had an intake blockage (leaves etc) that self cleared...but it made me hyper examine the engine...<br /><br />any help sure appreciated!<br /><br /><br />edhappe@comcast.net

 

[Don S]

Re: Mercruiser 228 overheating?

If you are talking about just to the side of the carb, yes it's normal. There is a heat tube in the intake manifold to heat the choke coil.

 

[84Ed]

Re: Mercruiser 228 overheating?

Hey Don, thanks for the reply....i was splashing water on either side of the carb but the water lays in the little wells that form next to the valve covers....more at the edge of the manifold, both sides....my worry is that water could flow to the front of the manifold, but not to the middle,(and possibly rear). do you know the normal flow of water through the intake manifold?<br /><br />thanks again....

 

[mangus580]

Re: Mercruiser 228 overheating?

84ed, the intake manifold has a passage that goes from one side to the other right under the carb that carries exhaust to heat the carb and keep it warm. the coolant only flows through the front and rear of the intake. From what you describe, you should be just fine.<br /><br />When you say your temp was way up, what was it up to? Maybe your thermostat stuck closed for a minute?

 

[mangus580]

Re: Mercruiser 228 overheating?

I need ammend my comment before, the coolant only flows through the front of the intake. Was reminded of that tonight when I was working on mine.

 

[84Ed]

Re: Mercruiser 228 overheating?

thanks for the get backs........that explains why the front of the manifold is so much cooler than the middle...<br /><br />Ed