ideal temp range - 89 mercruiser v8 305

nickcasa

Seaman
Joined
Nov 18, 2007
Messages
52
my boat runs awesome for an 89 cobia with a mercruiser v8 305 and se106 outdrive, however the temp runs at 190 to 195 all day no matter how fast nor how long i have it on for, any cause for concern? the middle of my temp gauge is 180 and the gauge / senders are new as is the se106 drive with 30 hours on it...water pump is new and thermostat housing...i did run it accidentally for 3 hours in the ocean with the muffs on, i totally forgot they were on there, what an idiot i am....wondering if i damaged the impeller....any thoughts on this or if you could post your temps on a similiar engine would put my mind at ease.
 

Bondo

Moderator
Staff member
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Apr 17, 2002
Messages
71,083
Re: ideal temp range - 89 mercruiser v8 305

wondering if i damaged the impeller....

Ayuh,.... That would be My Guess....

You should be seeing 140? to 160?.... depending on which T-Stat you used,....
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: ideal temp range - 89 mercruiser v8 305

Around 160 to 175 is where you should be running.
I would sure replace the impeller first after running with the muffs on like that. Not sure what would happen at higher speeds.
You should also check engine temp with an IR temp gun and verify the readings. How old are your manifolds and risers? They could be the cause also since you do run in salt water.
 

nickcasa

Seaman
Joined
Nov 18, 2007
Messages
52
Re: ideal temp range - 89 mercruiser v8 305

no problem impeller replacement, will do, with that said, anyone got a link on how to do this?
 

John_S

Rear Admiral
Joined
Jun 21, 2004
Messages
4,269
Re: ideal temp range - 89 mercruiser v8 305

Are Se106 drives, Merc compatable on the inside? ie not sure if a merc manual is correct for your drive.
 

nickcasa

Seaman
Joined
Nov 18, 2007
Messages
52
Re: ideal temp range - 89 mercruiser v8 305

had SE rebuild impeller on the se106, still running at 200, any other ideas what i should check next? i noticed on the tell tale, there is more water coming out the back on side than the other, is that the sign of clogged manifolds and risers? if so, do they make marine draino?
 
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