Normal Operating Temp

[kbuts34]

I have a 2004 Merc 4.3L raw water cooled, with a 160 F thermostat. Engine operates around 175 F give or take. It has a new impeller and thermostat. Is this with in normal range?

 

[Pete104]

Re: Normal Operating Temp

Yes

 

[KD4UPL]

Re: Normal Operating Temp

My 1997 Merc 5.7 has always run about 175. I don't know what the T-stat is. Yesterday I had it in some dang cold water with a light load and it ran closer to 160.

 

[kbuts34]

Re: Normal Operating Temp

Ok so I checked engine with an IR temp. T Stat housing read around 150 ( right by sender), exhaust manifolds 130 / 135, engine block 150. Boat Temp gauge was sitting between 175 and 200. Can I conclude that the Temp Gauge is off?
Or could it possibly be a bad temp sender?

 

[cr2k]

Re: Normal Operating Temp

2nd most inaccurate gauge on a boat.

 

[Brentathon]

Re: Normal Operating Temp

You know what you can do, if you have a multimeter with a thermocouple feature, you can pull a hose off, feed the thermocouple into the water passage and re-install hose, and get a very accurate temp reading of the coolant/water that way.

 

[fsjcowboy]

Re: Normal Operating Temp

2nd most inaccurate gauge on a boat.

That's kinda funny, but so true. Would love to see your rating scale of all the dash gauges from worst to first.

 

[sw33ttooth]

Re: Normal Operating Temp

i am going to take a guess at that,

1st trim, never adjusted properly.
2nd temp always close but no cigar.
3rd fuel hit a 5 foot wave meter goes off in 1 direction.
4th speed my speedo goes from 30-40 and gps says i am doing 38.
5th oil how do you really know?
6th tach pretty sure if its off its not on the right setting.
7th volts if this isn't accurate you need a new gauge.

just my thoughts i'll be waiting to see if he replies on his.

 

[dubs283]

Re: Normal Operating Temp

1 - trim - needs to be adjusted only to read full down when the drive is in fact full down, if thats not the case, adjust as neccessary - the sender is not designed to read according to the increments on the guage, only to read full down when drive is fully down

2 - true that on the temp, but get a good look at it when at operating temp and remember the reading, if it goes higher = trouble

3 - fuel, yep will fluctuate but if really bad could be a faulty sender, or no baffels in the tank

4 - speedo, yeah right, you wanna go faster, drill the pitot hole bigger

5 - oil (same as temp)

6 - tach - should be pretty accurate, if not - yep, wrong setting or faulty tach/circuit

7 - volts, i see guages that read all over the place - some really high, some really low, best guage is a voltmeter at the alt/batt/back of guage

as far as rating accuracy, i don't have a preference, ive seen every guage read innaccurate, the two you need to be aware of at all times is temp and oil