no temp gauge, what is a psi gauge?

[Redfeathers kill]

Hello every one. Got a question for ya, hope its not to stupid. On my last boat which was a 15' hyrider with a 90 chrysler outboard, i had a temp gauge. I loved that gauge, it gave me piece of mind. On my new boat, which is a 17' forester with an 84 merc 90 inline 6, i have no temp gauge. It does have a gauge i am not familiar with though. the gauge just says PSI. There is a small black tube that exits the gauge on the rear under the dash and follows the wires to the motor and goes around to the back of the motor and is plugged into the block between 2 plugs. The hose is a very small but hard black plastic like material and the way it is hooked to the block is similar to how your water is hooked to your frig at home for your ice maker. What is this gauge? is this a different way of measuring my water temp or pressure. I have been told to just make sure that there is water shooting out the water outlet and that then i know my motor is cooling. but if it stops shooting out how long before engine problems occur, if i don't see this happen right away. I tend to prefer to look forward when im driving and not back at a stream of water. but at the same time i want to know when my engine is in danger of damage before its to late. Can i put a temp gauge on this motor if so, how?

 

[achris]

Re: no temp gauge, what is a psi gauge?

That pressure gauge is waaaay better than a temp gauge. It indicates the pressure of the water inside the engine block. If the pump fails (damaged impeller or picking up a plastic bag etc) then the block pressure will drop immediately, a long time BEFORE the temperature rises.

On an outboard I would trade a hundred temperature gauges for just one water pressure gauge.....

Chris........

 

[Redfeathers kill]

Re: no temp gauge, what is a psi gauge?

Thanks for the info thats real good to know.. Here i thought i was missing out but sound like im better off. What so i look for the gauge just dropping off. or will it slowly go down.

 

[Redfeathers kill]

Re: no temp gauge, what is a psi gauge?

sorry dumb question on my last post you clearly spelled it out on your post chris. sorry. thanks again for your knowledge and Patience with this boating newbee

 

[sschefer]

Re: no temp gauge, what is a psi gauge?

This is a subject that comes up often. I don't challenge the fact that a pressure gauge will tell you everything you need to know but a combination of pressure and temp gauges can be a godsend. The problem is that most people don't watch the gauges often enough to catch the problems that are occuring. The most effective warning system for the average boater is still the temp alarm and if properly serviced, works well.

If you decide to install a pressure gauge to use as a monitoring system, you must ensure that your cooling system is in perfect condition so that you have a baseline that you can use to detect problems. If you don't, you may think your cooling system is in good condition when in fact it is near failure.

I use both so that I can also monitor the lean and rich state of the engine. If I have good water pressure and a higher or lower than normal temp condition then I know I need to do some work on my fuel delivery systems. A lean engine might idle through the wake zones with good water pressure but temps could sill get high enough to cause damage.

At WOT when the poppet valve is wide open your engine should be running around 135-145 degrees. If it's running down around 130 you may be loosing horsepower and wasting fuel with too little timing advance or a too rich fuel mixture.

So there's my argument... At the least run the pressure gauge and leave the audible alarm hooked up but if you can run a temp gauge also then do it.

 

[nbnewbie]

Re: no temp gauge, what is a psi gauge?

sschefer i agree with you the only thing i would add is with a temp guage you can see when a temp problem is coming with the alarm only by the time it goes off you're already hot enough to do damage as in my case a few years ago with the wind in your face, the outboard roaring, and 60 yr old ears you can burn a hole in the top of #3 piston before you realize the buzzer is sounding off

 

[sschefer]

Re: no temp gauge, what is a psi gauge?

sschefer i agree with you the only thing i would add is with a temp guage you can see when a temp problem is coming with the alarm only by the time it goes off you're already hot enough to do damage as in my case a few years ago with the wind in your face, the outboard roaring, and 60 yr old ears you can burn a hole in the top of #3 piston before you realize the buzzer is sounding off

Agree. I try to set the tone for the average boater. You and I would check the temp gauge because after 60 years we know better. The fact is, most people wouldn't do it often enough so the best deal for them is an audible that will at least let them know that something has gone wrong. Most of them don't read the owners manual, don't know what the alarm tones mean and just figure it'll be o.k. if they fix it tomorrow. The odds of them paying attention to a gauge is about zero.... Just read a few of the posts on here.. LOL..

As a side note - Sorry if that sounds a little gruff to you average boaters who are learning your first lessons.

 

[rodbolt]

Re: no temp gauge, what is a psi gauge?

for years and years merc inline 4s and sixs had NO alarms.
water pressure gauge is nice,still possible to overheat it with good water presure,temp gauge is nice,sometimes when you look down at it its posible to wonder,how long has it been pegged?
the audible WILL alert you that a problem is occuring.
if your hard of hearing use a twin horn setup like a car or the boat horn.