Water temperature vs. water pressure gauges

[seawings]

I am a new boat owner and also thinking of adding a water pressure gauge. I have a Mercury 150 Saltwater with a "water temperature” gauge. The range is 0 to 220 degrees, initially didn’t notice it registering beyond about 175, then I noticed it was up to almost 200. I contacted my local marina and they said “ Mercury’s always run hot”. I didn’t like that answer and contacted Mercury who basically said the same. They did allow that they wished that the boat manufacturer wouldn’t put “temperature” gauges, rather a water pressure gauge which “they” said tells much more. There are too many variables when using a temperature gauge…and sure enough after 10 hours of use the temperature now runs anywhere from 160 to 200.<br /><br />Comments would be appreciated.<br /><br />Thanks

 

[gss036]

Re: Water temperature vs. water pressure gauges

I would agree with the Mercury contact. The temp gauge on my 89 200 very seldom ever reads over 100 degrees, so I don't know if it really works or not, but I do know that the high temperature alarm works as I have had it go off when the water pick-up got clogged by kelp and when the water impeller decided to give up. I have been told by Mercury mechs that the water pressure guage if much more critical than the temperature guage. If I had a new engine, I would definately invest in a temp guage.

 

[Trent]

Re: Water temperature vs. water pressure gauges

Water pressure to me is more important! No pressure...no cool

 

[jimalsk]

Re: Water temperature vs. water pressure gauges

What is wrong with having both?? Two's better than one. Right?

 

[whotheman77]

Re: Water temperature vs. water pressure gauges

I am a merc. tech and I love water pressure gauges. Temp gauges are good to have but I recomend the water pressure gauge and keep an eye on that telltail or "pisser" as some people refer to it. Your alarm will tell you if you are getting hot, just make sure your horn is connected and working properly

 

[wjphunter]

Re: Water temperature vs. water pressure gauges

pressure guage is very easy to install,and is cheap insurance. I have to agree w/supertech77 & alaska rr.

 

[KCLOST]

Re: Water temperature vs. water pressure gauges

Either one has its purpose... I have both and watch both of them equally as much...<br /><br />The pressure guage will tell you what and when things are happening with your motor... Idle pressure, when the stats are closed and open... Cruise pressure, when the poppet is closed and open. And WOT pressure, and when you might trim out too far and loose water intake into the lower unit... I love it for all of those reasons, especially the last one...<br /><br />By the way, My 86' 175 runs at 200-215F at WOT in the summer... The Sender is measuring metal on the cylinder head not water... Good luck.

 

[dajohnson53]

Re: Water temperature vs. water pressure gauges

Originally posted by KCLOST:<br /> ... The pressure guage will tell you what and when things are happening with your motor... Idle pressure, when the stats are closed and open...

What is the water press. gauge going to do when the Tstat opens?