Still Having Temp issues---Please help!

[lcmains1]

I have been "chasing" temp issues for a couple weeks now. I have a 1990 merc 5.0lx. My tempeture gauge has not risen above 120 (boat is new to me so I don't really know past history temps) I have replaced the thermostat (140 degree) I have replaced the water temp sender. The last thing is the gauge i guess.

This weekend I got a infared thermometer. I warmed up the engine and here is what I came up with:
This was after a good run at 3800 rpm on the lake

Raw water in--63 degrees
T stat housing 142 degrees
Where sender screws in to housing 143 degrees
Exhaust manifolds 180 degrees
Risers 135 degrees

Does all this seem like the proper temps? Everything seems normal but I am questioning the temp of the manifolds. I assume they are just hotter as the exhaust is very warm.

Any suggestions?

 

[tschmidty]

Re: Still Having Temp issues---Please help!

Those temperatures all seem pretty reasonable to me. What is the temp issue you are chasing? Do you have another thread?

 

[Monte1961]

Re: Still Having Temp issues---Please help!

Hey that sounds good to me also. I wouldn't be to concerned at the water temp unless it rose to about 210% or above.

 

[Monte1961]

Re: Still Having Temp issues---Please help!

And as for exhaust manifolds, Thats not bad either.

 

[lcmains1]

Re: Still Having Temp issues---Please help!

I am not chasing any tempature. Somewhere between the sender and the gauge I have an issue as the gauge is reading below 120 degrees (I am thinking a bad gauge at this point)

I was just wanting to be sure that my manifolds were not getting to hot. Everything else seems to be around 140 degrees (my thermostat is 140) so everything seems to be working as it should, I must have a bad gauge...... The engine is running great!!!!

Guess its time for a new gauge....

 

[Monte1961]

Re: Still Having Temp issues---Please help!

Before you going replacing parts, as it could also be the temp sending unit itself. I would also be looking at that alsoIE: loose or bad connections from temp sensor back to the gauge.