honkyshaq

2003 Cobalt 220S - 496 MAG HO - Serial# OM628033

Second owner but a very well kept boat.

Last season, at the end, we experienced a one time overheat alarm. Being close to the end of the season we winterized and planned to rebuild the raw water pump this year with other pre-season maintenance.

Rebuilt pump using stainless wear plate kit. Went flawless. Old impeller was completely in tact but showed signs of cracked impeller blades and housing was scored. On test run overheat alarm sounded within one minute of cruising at about 4000 RPM. Faster than before.

On inspection everything looked good except for a slight drip behind the engine near the Bravo cooling water supply hose that passes through the transom.

Question is this...If the leak is the "brovoitis" hose, would it be possible that the rebuilt pump could be working so well as to suck air and create a flow/pressure issue?

Also...Is there any affordable code readers available for the early 03 Mercury computer?

Either way, my plan is to cut the hose and plug the end leading to the pass through, leaving the other end open to allow water to somewhat cool the B3 drive and install a through hull pick up with the correct 1-1/4" supply for the engine.

Thoughts...Pros...Cons??

THANK YOU!!!

Camalot

Camalot

double post

Sydwayz

iTrader: (1)

www.rinda.com It's not cheap, but worth every penny.

Adding this from another thread:
Also, do a search on this topic. Does your boat have a fresh water flush system installed? I have seen those factory systems that are installed by the manufacturer gum up with seaweed and other debris where the check-ball allows enough water to pass at low RPM, but over 45mph or so, the boat overheats. Remove the check-ball in the Tee. It is not needed. Yes, there can be corrosion problems in the tubes through the transom assembly as well. As a matter of fact, the check-ball can CAUSE corrosion issues because it does not allow the hose to flush water backwards though the transom assembly and back out the drive.

Also, don't cut anything and change plumbing until you determine that the water line through or after the transom assembly is corroded. This can be fixed/replaced.

BUP

iTrader: (9)

FT Worth Texas turn key boating

BUP

iTrader: (9)

If you are using the OEM impeller housing - you can not use the standard sized impeller when you install a drop in SS wear plate. The deal is you are taking up space within the housing so with that said the stock sized impeller is too big - again the reason is because of the room taken up by the SS drop on wear plate. Also if you have side wear in the housing the drop in plate does zero for that.

I would not do any mods of water flow to your stock engine.

Keith Atlanta

Back up a little.

Did you use the rebuild kit that came with the impeller? If you used the kit that comes with an impeller that is the softer durometer you may need to use a different kit. The kit with the smaller, softer impeller made my engines run 20 degrees hotter. I swapped it out with the kit that uses the stock impeller and it ran fine.

BUP

iTrader: (9)

I have the proper kit and its a OEM correct fit impeller. its fitment is correct per the ss wear plate spacer that is drop in. Like I said YOU CAN NOT SHOVE / CRAM a OEM stock sized impeller because some of that room is taken up by the SS drop in wear plate.

Example and an example ONLY about SS drop in wear plate spacers or what ever ---- if I have a 2 inch space that a round 2 inch peg drops into but I add a 1/8 inch spacer in that 2 inch space I now no longer have a 2 inch space to work with. I only have 1 and 7/8 space for a 2 inch peg. Its that simple. You need the correct impeller for the space that is taken up by the spacer. Impellers work and flow properly in the spec tolerances they were made and tested for.

Anyways is taking your boat into a OEM dealer to get it fixed correctly and get back out the water like the boat was intended for out of the question ? IMO it would be cheaper to do so by far plus some other issues that can get pointed out that might need to be addressed. Very common as I see this all time more than one issue going on especially with 496 s.

A water volume output testing is the best way to figure out if you have water flow issues and water cooling section testing is another great way to pinpoint whats exactly going on. A scan tool will never see these issues. Just because one installed new impeller and some bandaid aftermarket drop in plate does not mean the water flow volume is correct. Water flow volume is so important more so than water pressure.