Nebbie post, I apologize if its been answered in an old post...
I have a 7.4L 454 Bravo 2 Merc (raw water cooling system) that overheated when I took it out of slumber yesterday. I went thru my checks on land with some muffs. Wasn't sure how much water was suppose to suck up thru the hose but things seemed normal.
After I "confirmed" or lack there of everything was fine I dropped it and idled down the channel keeping an eye on the temp guage. Things, again, seemed to be operating normal. I got out on the lake and gave it some juice and the temp guage went from 120 to 180-190 quickly. The alarm sounded, I shut everything down and popped the engine hatch. There was mild smoke, which seemed to be the water steaming from exhaust outlets. I didn't want to push the potential overheating damage so I didn't try to fire her back up.
Questions I have are the following...
1) 96' 250CR Crownline (eng specs above) - is there a pump in the outdrive or is the only pump for water cooling front-mounted on the engine?
2) If this is the only pump (front-mounted on engine) does the inlet-hosing run under the engine all the way out the exhaust bellow and down to the outdrive water inlet slits (where muffs would go)?
2) Does this sound like a water pump issue or are there other potential causes for such overheating issues?
3) I'm somewhat hands on but is this one left for the professionals?
4) What are the typical costs for impellar replacement? Full pump replacement (what are the odds the actual pump goes bad as opposed to just impeller)?
5) Where exactly is the exhaust / exhaust water being dumped at?
6) Should I be looking anywhere else (cooling system) to trouble shoot?
Any help would be great! I'm trying to learn everything I can via-books but talking to someone who has experience is worth its weight in GOLD!
JC
Lake St. Clair, MI
I have a 7.4L 454 Bravo 2 Merc (raw water cooling system) that overheated when I took it out of slumber yesterday. I went thru my checks on land with some muffs. Wasn't sure how much water was suppose to suck up thru the hose but things seemed normal.
After I "confirmed" or lack there of everything was fine I dropped it and idled down the channel keeping an eye on the temp guage. Things, again, seemed to be operating normal. I got out on the lake and gave it some juice and the temp guage went from 120 to 180-190 quickly. The alarm sounded, I shut everything down and popped the engine hatch. There was mild smoke, which seemed to be the water steaming from exhaust outlets. I didn't want to push the potential overheating damage so I didn't try to fire her back up.
Questions I have are the following...
1) 96' 250CR Crownline (eng specs above) - is there a pump in the outdrive or is the only pump for water cooling front-mounted on the engine?
2) If this is the only pump (front-mounted on engine) does the inlet-hosing run under the engine all the way out the exhaust bellow and down to the outdrive water inlet slits (where muffs would go)?
2) Does this sound like a water pump issue or are there other potential causes for such overheating issues?
3) I'm somewhat hands on but is this one left for the professionals?
4) What are the typical costs for impellar replacement? Full pump replacement (what are the odds the actual pump goes bad as opposed to just impeller)?
5) Where exactly is the exhaust / exhaust water being dumped at?
6) Should I be looking anywhere else (cooling system) to trouble shoot?
Any help would be great! I'm trying to learn everything I can via-books but talking to someone who has experience is worth its weight in GOLD!
JC
Lake St. Clair, MI