Another Cooling system question

[Lemay88]

I know, another cooling system question but no questions are stupid, right!!

When the thermostat is closed (engine cold). Is the radiator/pressure bottle section completely "sealed" from the engine/heater core section???

I am thinking my thermostat is stuck open and I am trying to be 100% sure before attacking the job.
Reasons why I'm thinking thermostat is stuck open:

1. Upper hose gets hot before thermostat opens.
2. Finally had a warm day and let the car idle with some 1500 RPM (have some warm up and cool down to "burp" the system) to help get to temperature for 20 minutes. When temperature reached around 200, fan came on and never stopped. Temperature stayed at 203.
3. Same experience as #3 in cool weather and fan would stop and go at PCM programmed temperature.
4. When I squeeze the heater core hose, I can see coolant level fluctuate in the pressure bottle.

So, any opinions and comments are welcome.

Thank you

Ben

1997, red, R/T, stock

P.S. One last detail, radiator as been recored last winter, that is why I was "resetting"the cooling system with brand new coolant.

[98RedGTS]

Sounds like the t-stat may be open. The upper rad hose really shouldn't get hot until it opens.

[SlowPoke McGee]

Do you have a stiff hose? *looks at Dave6666 for a solution*

[Lemay88]

lol, no fixed the stiff hoses...lol
I learned from this forum and I would say from Dave6666 that the first thing to check is air in the system.
I can confirm that 90% of the over heating/ cooling problems are from air in the system.

Ben

[dave6666]

Yo slotardmcgreasy. Has your mom let you drive the viper yet? lol when you grow up you may ending knowing completely less about everything than I do.

Meh. Bye now k?

[dave6666]

I know, another cooling system question but no questions are stupid, right!!

When the thermostat is closed (engine cold). Is the radiator/pressure bottle section completely "sealed" from the engine/heater core section???

I am thinking my thermostat is stuck open and I am trying to be 100% sure before attacking the job.
Reasons why I'm thinking thermostat is stuck open:

1. Upper hose gets hot before thermostat opens.
2. Finally had a warm day and let the car idle with some 1500 RPM (have some warm up and cool down to "burp" the system) to help get to temperature for 20 minutes. When temperature reached around 200, fan came on and never stopped. Temperature stayed at 203.
3. Same experience as #3 in cool weather and fan would stop and go at PCM programmed temperature.
4. When I squeeze the heater core hose, I can see coolant level fluctuate in the pressure bottle.

So, any opinions and comments are welcome.

Thank you

Ben

1997, red, R/T, stock

P.S. One last detail, radiator as been recored last winter, that is why I was "resetting"the cooling system with brand new coolant.

You will not move the air out of the places it gets trapped by idling in the garage. Take the car out and drive it.

If you can see the level in the surge tank go up and down as you squeeze a hose YOU ARE LOW ON COOLANT. Geesh man.

How do you know if the thermostat is open or not?

With air in the system your fan operation can be erratic. Fill the damn surge tank up, fill the damn overflow tank up, and make a few hot laps around the neighborhood. Cool the car, check levels, repeat.

[ssgsnake]

I found the small hose on the overflow was letting air in on my 95 , I put a small clamp and solved all the issues it was causing air in the system.

[Lemay88]

Pressure tank is at the rim and fascia tank is up top the full mark.
I thought that running warm up and cool down cycle at 1500 rpm (in the garage) would do the same job...just learn so more.
Weather up here is not quite perfect for "hot laps", we don't all have the chance to live in Viper weather all year round.
Thanks Dave, I'll take your advice and as soon as weather gets better, I'll give it a go and comeback with results

Thanks again

Ben

[SlowPoke McGee]

Yo slotardmcgreasy. Has your mom let you drive the viper yet? lol when you grow up you may ending knowing completely less about everything than I do.

Meh. Bye now k?

Ironically, even my mom knows not to use Texas tap water in her radiator.

[Lemay88]

Just want to update.
Weather has been nice and I've been putting miles in the Viper.
In steady driving and stop and go mode, temp gauge stays in the happy range, thanks to new re-core 2 row rad (no "upgrade" here and cool weather (May in Canada, eh!!!).
Now, by squeezing the upper hose I know there is still air in the system but still, temp stays ok...but, the fascia tank level is coming down every time I go out and drive, sign that the system is self purging of air. (Dave was right)
Here's a tip, re-tight your overflow tank to pressure tank hose clamp when the engine is hot, I was surprise how much I was able to tighten it compare to cold.

Now, gotta go drive some more, gotta get this air out of the system.

Ben
1997, stock R/T