Temp rising

[tic]

Re: Temp rising

Hey sorry .. just trying to help.. rough crowd!

 

[smithrock]

Re: Temp rising

I would bet your IR gun is a lot more accurate. Pull the wire off the sender on the engine and test the resistance of it when the temp gauge shows 210. Check in the manual, it should give ohm ranges for the sender. Probably have the wrong type sender more than it's going bad.
The temp on the thermostats is when it starts to open. Underload, the 140 may very well be about the same or maybe only 10 degrees lower.

I should be able to do that tomorrow So keep the wire on until it reaches 200-210 then pull it off? -I'll get back to you, thanks!

Knowing the gun is more accurate, I'm feeling a little better about the temps! But I want to get it where it's suppose to be!

 

[tic]

Re: Temp rising

I guess I'm stupid.. I have an IR temp gun as well... I recently replace my T-stat too.. The old one had bits of rubber impeller jammed into the spring probably keeping it stuck shut.. How exactly do you use an IR temp gun to see when your T-stat is opening when it's inside the T-stat housing?... Point it at the output hose to the manifold?....

 

[Don S]

Re: Temp rising

You can't use the IR gun to see exactly when the stat opens, it only tells you what the temps are.

 

[smithrock]

Re: Temp rising

So keep the wire on until it reaches 200-210 then pull it off, or take it off from the start?

 

[smithrock]

Re: Temp rising

Tried to check the sender, but I've looked all over and can't find the numbers I'm looking for as far as resistance for the temp sender. I'm in the process of trying to secure manual #7 hopefully that will help!

I did infact check it yesterday, and discovered one of my hoses that goes into the thermostat housing was pinched just a little, so I corrected that and my temps were lower on the IR gun-never got higher at the sender than 168, the gauge however was still reaching at times 200+. I'm still waiting for my 140 thermostat to arrive so I can install it.

If I need a new sender, what part # do I need?

 

[smithrock]

Re: Temp rising

forgot to ask, is the sender marine specific or regular automotive?

 

[obezag]

Re: Temp rising

My sender was reading high after I had removed it and put it back in. Took it back out and cleaned the threads in the t-stat housing really good, so it has good contact and it reads normally again. Just a thought.

 

[smithrock]

Re: Temp rising

I'll give it a shot, couldn't hurt! Thanks.

 

[smithrock]

Re: Temp rising

Installed the 140 thermostat, temp did go down some on the IR gun. Highest reading on the gun at the sender was 155, pretty much stayed between 137 and 144 most of the time though. My gauge was at times still reading 200+. I did notice in a span of like 5 sec. the gauge went from like 220 down to just under 160. Any ideas on what's going on?

And this info was obtained from running the boat for 2 hrs. out in the water yesterday

 

[Don S]

Re: Temp rising

Did you check the resistance on the temp sender as talked about earlier in this thread? If they were good, change the gauge. If they were way off, change the sender.
You can even run a seperated wire from the sender to the gauge to make sure the wireing and connections are ok.

 

[smithrock]

Re: Temp rising

Did you check the resistance on the temp sender as talked about earlier in this thread? If they were good, change the gauge. If they were way off, change the sender.
You can even run a seperated wire from the sender to the gauge to make sure the wireing and connections are ok.

Yes, I did try it but I'm still waiting for manual #7 to arrive so that I can find out what range I'm looking for. (not sure if I did it right). Running a seperate wire sounds like a good idea, I'll try it. Did the numbers on the IR gun look okay to you?

 

[Don S]

Re: Temp rising

The service manual doesn't give any ohm reading, says to just change the sender.
Here is from a different manual, Merc has been using the same sender for years on everything.

Water Temperature ..........Ohms Reading
140?F (60?C) ......................121-147
194?F (90?C) .........................47-55
212?F (100?C) .......................36-41

You temps with the gun sounds fine.

 

[smithrock]

Re: Temp rising

The service manual doesn't give any ohm reading, says to just change the sender.
Here is from a different manual, Merc has been using the same sender for years on everything.

Water Temperature ..........Ohms Reading
140?F (60?C) ......................121-147
194?F (90?C) .........................47-55
212?F (100?C) .......................36-41

You temps with the gun sounds fine.

Thanks, Don!

Just to make sure I do it right, what setting does my ohm meter need to be on?