Engine Temp..Goes up and Down but Why?

[ACerf]

It appears that after my 03 SO rolled over 40K and I changed the Anti-Freeze. It now seem that it can not make up its mind has to what temp it wants to run at. When I first got the truck it would run almost always at 195 degrees, whether we were towing or not, climbing hills or not! Now it wants to go up to about 210 when we are climbing. Not that this is all that bad, but it just seems funny that it all of a sudden wants to do this.

Has anyone else had this experience? Or either that I just never paid any attention to the gauge before! Oo.

 

[mberry]

I would venture towards the latter. It's easy to miss the temp swings if you aren't watching it closely. Mine swings when it is cold and you can see the temp drop as the thermostat opens and closes. When it's hot like it is this time of year, i gets warm fairly quickly and sometimes goes to 210 or so when going uphill slowly in traffic.

 

[Midnight]

Double check the strength of the new antifreeze mixture. If it's too strong or too weak it will create problems.

 

[GShail]

Take a look at the fan clutch.

 

[rbattelle]

What antifreeze did you put in it?



-Ryan

 

[p-Bar]

Hey Guys,

What if we changed the thermostat to a 180 degree , I know they run hot to keep them leaned out for emissions ect. ,any other draw backs??



Don

 

[ACerf]

What antifreeze did you put in it?



-Ryan

I used Prestone Global, It is new and approved for DC products. The cooling system was completely cleaned out before adding the new stuff.



It was mentioned about temp dropping quick. This is true in my case as well. It appears that as fast as it goes up in drops as fast, or faster.

 

[nickleinonen]

Hey Guys,

What if we changed the thermostat to a 180 degree , I know they run hot to keep them leaned out for emissions ect. ,any other draw backs??



Don

i personally see no major benifit to running a 180 over a 190 [other than a little cooler lube oil temps. ]... i actually want a few degrees hotter t-stat [195° maybe?] but 99% of my driving is empty. . if you were towing at gross weight all the time and down in the southern parts where the ambiant temps get high, it could benifit you to run a cooler stat, but if you are more north and get cold come winter, i wouldn't change it.



was your A/C on when you noticed the temp increase/decrease???

 

[p-Bar]

Is it possible there were some air pockets in the block causing this irratic behavior

 

[mberry]

I wouldn't count on air pockets and I also would not change the t-stat to a cooler one. I wouldn't worry too much about it unless it gets hot and stays hot. On the other hand, you could change the t-stat out for the same temp and see if that helps any.

 

[rbattelle]

As usual, I agree with Nick. And Mberry. Don't worry about it unless it gets hot and stays hot. Just keep an eye on it...



-Ryan

 

[GShail]

Mine will get hot while towing on grades and will stay hot

 

[JThiessen]

silly question...

So, what made you change the fluid in the first place? These things were supposed to be set up to run longer than 40K/3yrs. I'm running the factory fluid still at 47K in my '03, and I've always jumped around from 190-210 per the guage. I've never owned a vehicle that didnt have temp swings depending on wind conditions/load/etc.

 

[gsbrockman]

I wouldn't count on air pockets

Sounds like an air pocket problem to me.

Greg