Temperture on Merc 8.2 MAG ECT Bravo IIIx w/DTS 380 HP

[Philip]

What should be the standard engine temperature when running? I am showing 172...174 if I can going all out...170 if idiling or going slow.

Sometimes If I go from a running speed to stop, engine climbs to 177 and then backs down...
2013 with Original Water pump. Boat only has about 120 hours.

 

[Espos4]

Depends..,,.what is the rating on the thermostat?

Have you noticed any changes is engine temperature? Has it always performed as you described above? Or are these numbers elevated over previous seasons temps?

 

[Philip]

These numbers are slightly elevated from last year when it ran at 170. Concerning to me to is when I stop after crusing a bit and it escalates to 177. Earlier this season I sucked up a lot of mud / seaweed and dealer came to my dock and cleaned out intakes. Prior to that it was ocasiinally going into guardian mode when I came to a stop. They want to replace water pump after this season.

 

[Philip]

Don’t know what thermostat rating means? Is 172 a reasonable termperture to run at? Is that close to normal?

 

[Espos4]

If you have a 160° thermostat, it should run right around 160°.

If it’s a 170° thermostat, then it should run right around 170°.

I imagine you have closed cooling with that motor.
Water pump service could help.
Also, if you sucked up a bunch of mud, you may need to have the heat exchanger cleaned out. You may have some blockage in there.

 

[Philip]

Got it. This is very helpful. Thank you.

 

[paulswagelock]

I believe the stock unit was 165 if I remember correctly.
Getting into the upper 170 range likely is the beginning of a water flow problem.
What is your raw water pressure at idle, 3000 rpm and WOT?

 

[Philip]

Idle 6
No wake zone 9.5
3000 27
WOT. 34 to 37

 

[Espos4]

Are those numbers oil or raw water pressure??

Seems a tad high for raw water pressure numbers.

 

[Philip]

Water numbers.

 

[scoflaw]

Yup, sounds like you have a restriction on the outgoing water

 

[Philip]

Yup, sounds like you have a restriction on the outgoing water

Thank you.
If all is well what should they be approximenlty?

 

[scoflaw]

Mine used to run at about 1 at idle and 17 WOT

 

[Philip]

Ok got it. I will have dealer look at it and advise what they say. Will be a few weeks or may just wait till end of season in early Oct.

Thank you.

 

[Espos4]

Similar numbers here.

 

[Philip]

What are those numbers if you can share ?

 

[scoflaw]

Your fluctuating oil pressure probably has nothing to do with the clicking. Could be the flappers in your Y pipe or a U joint in your drive. Where does the noise sound like its coming from ? Is it random, does it have a rhythm to it ? All these clues help to pinpoint it.

 

[Espos4]

What are those numbers if you can share ?

My raw water pressure numbers are similar to what Scoflaw reported in post #13