4.3 Merc Running on hose ?

[JJJ]

Hi, when running my 4.3 cobalt on the hose the on side riser and exhaust gets much hotter than the other side. Is that normal? Even at idle.<br /><br />Or do I have to pull the riser to see if it is plugged (manifold is cool on that side)?<br />thanks

 

[Don S]

Re: 4.3 Merc Running on hose ?

When running on the hose, neither side should get hot. How old is your impeller?<br />How old are your manifolds and risers? Are you in salt or fresh water. Are you fresh or raw water cooled? What year engine?<br />It wouldn't hurt to pull the risers of and inspect them if they are 3 or 4 years old.

 

[JJJ]

Re: 4.3 Merc Running on hose ?

Don't know on many of the questions, 96 Cobalt, mostly fresh but some salt and raw water cooled.<br /><br />I'll pull the riser after all it is only 1 gasket. <br /><br /> What I wasn't sure of was why the manifold was cool- must have bypass passages internally?<br /><br />Thanks

 

[JJJ]

Re: 4.3 Merc Running on hose ?

Don't know on many of the questions, 96 Cobalt, mostly fresh but some salt and raw water cooled.<br /><br />I'll pull the riser after all it is only 1 gasket. <br /><br /> What I wasn't sure of was why the manifold was cool- must have bypass passages internally?<br /><br />Thanks

 

[JJJ]

Re: 4.3 Merc Running on hose ?

Ok pulled the riser on the starboard side of the engine and it looks ok - flows water well.<br /><br />4.3 Alpha1 port side exhaust is cool to the touch, starboard side the riser and hose get hot (fairly warm to the touch) BUT the manifold stays cool.<br />This is all on the hose, but if I remember correctly that side ran warmer last year on the water but not so hot you couldn't touch it.<br /><br />Pulled riser - no moisture in the manifold and the riser flows freely.<br />Some corrosion in the manifold BUT if it was plugged wouldn't it get warm also OR can water flow around inside it?<br /><br />RAW water pump is one yr. old - I've only had the boat 1 yr and I just looked through the gentlemans records.<br />Manifold and risers are 3 yrs old.<br /><br />Any Ideas????<br />thanks