Radiator temp in/out and temp gauge readings

[mrdonut12]

Bingo!! The thermostats should open wide and represent
no restriction to the flow of coolant. You have 2 bad ones.
Don't go to the parts store. They'll likely sell you
cheap junk. Go to a Cummins dealer and get factory parts.
Regarding the coolant, you can test what came out. It should
test -34 degrees, that's a 50/50 mix. I've found that coolant
testers lose accuracy with age. Calibrate it using a known mix
of 50% coolant and water to see if the tester is accurate.

George Witt
81 FC 35
Lincoln, Nebraska


--- In WanderlodgeForum@yahoogroups.com, "transit360"
wrote:
> So I took out my thermostats on the 8.3 Cummins. Two small ones,
> as you might have guessed. Looked a little rusty in the thermo
> housing by the way.
> Put them in water and heated them to boiling. Each one barely
> opened enough so you could see daylight from the bottom side.
> I took some needlenose and pulled the thermostat rod out. It's
> about an inch long. I'm assuming that most thermostats are the same
> so correct me if I'm wrong, but shouldn't the thermostats be capable
> of opening up the full rod length at temp well over 200? Possibly up
> to an inch? Just wanted to be sure to get a second opinion. I'm open
> to any fact that may be evident, which includes a thermostat that
> could possibly be designed to open by the slightest of gaps.
> However if the thermostat is supposed to open wider, then that
> means that the thermostat opened partially at operating temp, thus
> the coolant flow would have been reduced, thus making it get hotter
> under demand.
> Don't worry, I'm going to the parts store tomorrow to get two
> new thermostats and I'm testing them as well and then replacing the
> old ones. Just wanted to double check and get a full understanding
> of each mechanism and function, of even a thermostat rod.
> Also, I'm going to test my antifreeze mixture in the engine. It
> looked a little thin. Do I need to do this after I run the engine so
> it's evenly mixed, or can I just test any of the antifreeze I
> drained out b/c it's already mixed properly?
> I would really like to flush the system due to the
> brackishness of it, but I'm really hesitant until I get an full
> manual of all the systems of this bus. Would anybody know where I
> could get a manual for this Bluebird QBRE? I've contacted National
> Bus Sales in Georgia (the local Bluebird dealer) and no luck yet.
>
> Thanks
> Steve
> 2 '98 QBRE Partybuses
>
>