Low water pressure and running warm
 

I have a 99 fever that all the sudden yesterday had the alarm go of and starboard motor was running right around 200 while port was 170, the water pressure gauge for starboard only gets about 10-12 psi now when it use to be 25-27 which is what the port side runs, While cruising at 3k rpm port is about 13-14 and starboard is 7. Until yesterday they had always ran about identical. Any suggestions where to start to fix it?

What engines are you running ?? sounds like a sea pump took a dump

You don't say what motors, but the first thing to check would be the sea water pump impeller.

My bad, 502 mags with bravo 1's

Are you doing the work your self ?? remember to get all the little pieces, you engine should have a PS cooler that mounts to the top of the bell housing and an oil cooler that mounts vertical on the front, if it has cool fuel good luck getting to it

http://www.ebay.com/itm/Mercruiser-N...02bcc2&vxp=mtr

After looking at the drive today it looks like theyre might be some trash sucked up into one of the front water holes, what the best way to go about to trying to clean this out? And how hard is it to fix the pump?

I think you can pull the hose off from the sea pump leading to the drive and back flush it, its not hard to fix the pump, its being able to get to it, should be on the lower left side looking at the engine

Took the hoses off and the water in them was clean not gritty or anything, back washed them, there's one small hole in the very front of the drive that has what look like would jammed in it and is not flowing water should it be? Didn't get time to finish getting the pump off

The small hole is your speedo pickup. You can use a small drill bitl and drill out the wood. Best if you do that by hand. use vise grips to turn the drill bit.

Impellors last 2 yrs on Bravos. Sounds like its going south. Replace them on both motors

Took the pump off today and the impeller looks good any other suggestions?
http://i699.photobucket.com/albums/v...pszjo5gl6x.jpg

Could be a thermostat going bad or sticking, if you can find someone with a heat sensor you can check everything, some bigger marinas have them.

That's the only other thing I could think was thermostat. Can one for any Chevy be used like from auto parts store? Or does it need to be from mercruiser and what temp?

A bad thermostat wouldn't cause low water pressure

Then what else could be the cause

Plugged hose thru transom

With both high temp alarm and low pressure conditions, you have low flow issues

In your pic, did you look at all the vanes and the full length of them to make sure they arent broken off inside the housing, vs just glancing at the end shot?

Yes tool it out and it's all good

Since it's apart I did order a new housing and impeller, water was flowing back thru the drive pretty well last night

Also check hoses for cracks...if you have an air leak, you could be losing suction.

True enough.

Do you have a freshwater flush system?

it would if it was stuck open. and not moving enough water to get it to close .. feel youre exaust if feels hot youre clearly not moving water .or enough water .. easy way to tell ..exaust will feel warm to touch not hot ... if moving adaquate water past the or through the engine ..like for instance running without a t stat it takes large amounts of water to build water pressure as ther is no restriction .. becomes a strait through process .. i had to lower my water intakes half inch below boat to achieve 15 pounds of water pressure without a t stat ... good luck

If stat was stuck open, he wouldn't be running hotter.
It'd take longer heat up.

Running hot, lower pressure than norm. Restricted/lack of flow will cause both of those conditions

Replaced housing and impeller and put it in water on the trailer. pressure is a little better but still about half of what the other motor is running

please re read the post .. it clearly will stay open if its above opening point and will not close till it cools down , so if its not getting water it will stay open till it gets water as i stated ,,,and while its open youre water pressure will likely be lower due to no restriction ,, and if theres little water flowing it wont take long to heat up open or closed ,, lol

It's been back and forth if that will cause a problem so you're suggesting a thermostat?

take youre inlet hose that feeds the block off and start the motor ... see how much water pumps to the block .. only run for a few secs youll know right away if youre moving water .. if you think it could be thermastat .remove it . takes a sec run it see if it over heats , two very simple things you can do to try to narrow youre problem down .. good luck i run no stat in my engines .. but have oil stat to regulate oil temps ..

I had a similar issue last week with low water pressure and high heat. I pulled the thermostat and replaced it, flushed it, removed the circulator pump and it was fine, raw water pump removed it and rebuilt it, pulled risers etc, etc, After stepping back a day or two I went back and disconnected every hose and flushed them again and I got half of a impellor blade out of a hose that must have been from the previous owner because all of my impellor blades were in tact. Problem solved. It was very frustrating. Good Luck.

Ended up having some rocks and trash on the line gong to the cooler on the top of the bellhousing now running 4500 rpm or more its at 35pounds of pressure

Glad you found the culprit!!

35 pds is high be carefull

been through this....same motors ....thousands later, so back flush your cooling. Believe me , there is crap inside one or all of your coolers. Also, check your risers. My guess is that they are o.k. as your pressure is low. Mine was opposite , way too high.

have you been parking on the beach, or been in shallow water, maybe there you sucked up the sand & trash