2005 Merc 4.3 Alpha1 closed overheat

[the man]

I have a 2005 4.3L Mercruiser with an Alhpa one outdrive. Closed cooling, 190 hp, TKS. Engine serial # OW311876. Note: on the engine, it says Nov 2004 production. It is overheating even at an idle. I had the seawater impellar replaced but no change in condition.

I am looking for a drawing (diagram) of the cooling system so that I may try to diagnose the problem. The manuals posted online do not include this year. The similar, earlier year drawings show only one hose going to the manifolds; this engine has two on each manifold. Each manifold has a hose that leads to an apparatus on the top front of the block that I do not know what it is. If I can find a drawing that shows me direction of flow, where the thermostat is, and what this apparatus' function is, I can attempt a diagnoses. Otherwise it is all trial and error; mostly error.

 

[Don S]

Re: 2005 Merc 4.3 Alpha1 closed overheat

The manuals are there, assuming you are referring to the Adults Only and the DIY sticky at the top of this forum, you need #25 for the engine, 37 for the exhaust and cooling, and 41 for the TKS, and #14 for the outdrive.

Does this look like your system? Do you have the engine driven raw water pump?

 

[the man]

Re: 2005 Merc 4.3 Alpha1 closed overheat

Yes, that is the cooling system and yes I do have an engine (belt) driven raw water pump. I downloaded manual #37 and it appears to be the correct one for my cooling system. I will DL the rest and peice them together. Thank you!

One question: How was I to know this combination without your guidance? I have what I need now, but in the future, as I have several boats, is there a resource that will tell us DIYs the combination of manuals that we need to get all the information?

Thanks again! This is a great resource and saved my day.

 

[scutly]

Re: 2005 Merc 4.3 Alpha1 closed overheat

One question: is there a resource that will tell us DIYs the combination of manuals that we need to get all the information?

Yes there is a resource. His name is Don

 

[the man]

Re: 2005 Merc 4.3 Alpha1 closed overheat

Interesting follow up- the mechanic did not grease the impeller when installing and the new impeller would not spin so it stripped the keyway. He also did not test run it, as I found out when I finally fixed it and had water pouring out of manifolds.

So, grease or soap for that first few seconds when it will be running dry is very important!

 

[Fun Times]

Re: 2005 Merc 4.3 Alpha1 closed overheat

One question: How was I to know this combination without your guidance? I have what I need now, but in the future, as I have several boats, is there a resource that will tell us DIYs the combination of manuals that we need to get all the information?
Thanks again! This is a great resource and saved my day.

Yes, Don is a grate resource for information, But just in case you can't get a hold of him, Here is another way of looking up service manuals to use on your other boats.

http://www.4shared.com/file/185919662/99fd0dab/2008_Mercruiser_service_manual.html