I still say that t-stat is to cold and you will have heater problems and lower mpg.

 

I agree. I also think your original problem was just air getting in. You had a leak somewhere, and it wasn't bled properly.

 

So what's the suggestion? 195?
Is this a by-product of the talk about the UK and US rating thermostats to different reference temperatures? If so, how do we know that any other given number, say 195, is the correct number? The RAVE only mentions what degree range it should begin opening, not what temperature it should be at steady state.
RAVE just says to use an 88*C t-stat, which is 190.4*F. Then there is a blurb about how if it opens between 86 and 89*C(something like that), then it is satisfactory. So that appears to support the idea that 191 is when it should be opening, but not fully open?

I agree with you OK. And I don't even care that the problem doesn't appear to have been any of the components I replaced, I'm just glad it's fixed. And now I'm more familiar with the material condition of the system, which is nice.

 

Sure, now you know how stuff goes together and what is new, if you have a prob later...

 

I have a 195 and my truck runs at a steady 196.
200-205 in the summer with the a/c on and offroading.

 

Don't take this as questioning your judgement Spike, but how do you know that 195 is necessarily a more appropriate temperature than 191? If you shop for thermostats for this motor, you find ones rated for 88C (approx. 191F), and others for 195F. Here's the quote from the RAVE on thermostats:

"Note rating of thermostat is 88°C...Thermostat is satisfactory if it opens
between 85°C and 89°C."

(88*C = 190.4*F, 85*C = 185*F, 89*C = 192.2*F)

195 may allow the engine to run more efficiently, but I don't see that running 191 would cause problems. My heater definitely doesn't have a problem cranking out heat with the coolant at that temp.

 

I bought my t-stat at the dealer, they said the OEM temp for my truck was 195 and that was the t-stat they carried and used.
AutoZone lists the 195 as OEM temp.
My friends '99 Suburban with the 350 is a OEM temp of 195.
My wifes Volvo OEM temp is 195.
My old work van, a '04 E-250...195.

I dont think a 190 is all that bad, but a 180 def you will have problems.
And for some reason I thought you did install a 180.

 

Nope, just the 191. I think that's what came up on the computer at the AutoZone here. Or I may have selected it because it's closest to 88*C. I can't remember. Either way, it's good enough for me for now. Later on down the road I might switch it out for a better one anyway, because this one lags a bit opening up. It's not a problem, but it's not as good as it could be. Will probably end up with the 195 at that point as well.
Thanks for the info.

 

A 195 is way too hot.
The factory manual states that the thermostat should be fully open at 88c.
A 195 starts to open at 195, which is 90.5c and isn't fully open until mid 90's Celsius
I found this out by actually measuring the opening to fully open temps of new thermostats.
I use a 180, which is fully open at about 87-88c.

 

I've always thought there was some ambiguity in the way the manual reads. It doesn't seem to me that it really explicitly says whether the temperature it lists is fully open, steady state or just beginning to open (see quote from RAVE above, from thermostat renewal section).
Also, the fully open temperature doesn't indicate the temperature that you should see at steady operating state. The thermostat stays only partly open at running temp. If the coolant heats up and needs more flow through the radiator, then it has some room to open up and let a little more flow through. I would argue that a 180*F is likely too cool.

I'm calling the 191*F good. The manual asks for an 88*C t-stat. That's what I installed, and that's what temperature the coolant runs at. The numbers line up, and that's good in my book.