Question about Thermostat.

[jrod_okc]

A few weeks back my car started overheating one day. It goes up, then comes back down etc... Was not sure what it was.

It was cold today when i drove it, so i turned the heater on. When ever it starts to get hot, the heater stops blowing warm air. Does that make sense that it is the Thermostat?

 

[dave6666]

Have you checked the coolant level? What year is the car? Could be the waterpump.

 

[JonB]

THE YEAR MATTERS....... in some cases, a LOT. This may be one of those cases.

But this DEFINITELYY sounds like LOW COOLANT, with air in the motor of a Gen 1 or 2.

Gotta Burp Those G1-G2, the underhood tank is NOT a true coolant level indicator.

 

[bluesrt]

if its full of coolant, and the rad cap is good, u have a blown head im thinkin stick your nose in the overflow tank and c if it smells like hydrcarbons. just a scary thought

 

[JonB]

if its full of coolant, and the rad cap is good, u have a blown head im thinkin stick your nose in the overflow tank and c if it smells like hydrcarbons. just a scary thought

The overfow tank is inside the front fascia......even a pinhead would have a hard time doing that.

But the surge/pressure tank atop a 94-02 RF fender will reveal the same thing!

Snotty JonB~~~~~~:<!

 

[bluesrt]

yes thats it, the surge tank

 

[jrod_okc]

It is a 2000 ACR GTS. There is coolant under the hood in the engine bay.. Like coolant is spraying. I replaced the cap, and same result.

 

[bluesrt]

does it have heat at a idle? have you filled the coolant?

 

[jrod_okc]

I have filled the over flow.. I guess i need to pull the bumper to get to the actual coolant bottle? It has heat, as long as it is the temp is not rising.

 

[Dom426h]

no, pull the 4" rubber plug out of the wheel-well. Stick a bright flashlight in there to illuminate the level window below to the left of the plug. Most visible if you do this in a garage with the lights out.

If the whole window glows white your empty. You should see some green/orange/red in there.



to fill it, pull the hose that goes from the upper bottle to the lower one in the facia, stick a tiny funnel in her and pour

 

[Ratical2]

It is a 2000 ACR GTS. There is coolant under the hood in the engine bay.. Like coolant is spraying. I replaced the cap, and same result.

If I read this correctly, you need to find the leak and fix that. The car will overheat if the system is not pressurized.
Since you have already replaced the radiator cap, Check your hoses for cracks or splits.
Check that the clamps are tight.
If you have a leak, when the car heats up, the coolant expands and escapes. When the car cools down, the coolant re-compresses and air is drawn back into the system.

You can check the level of the recovery tank without pulling the bumper. That's what the circular access hole in front of the tire is for.
You can adjust the level using the hose at the top of your surge tank.


Was the car recently serviced. How old is the coolant?

 

[dave6666]

Step 1: Fix leak

 

[bluesrt]

if you have great heat at idle, but coolant guage is acting strange, check for hydrocarbons- but if you dont have heat at idle, make shure its full of coolant and all air is bled- one thing you have to make shure is haveing heat at a idle will excluded air in the system and thermostat and rad cap ect.

 

[steve911]

No mention was made about the radiator fan relay. If the fan doesn't come it will over heat too.

 

[speedracervr4]

Still having the same problem from your other thread...
http://forums.viperclub.org/rt-10-gts-discussions/642398-overheating-issue.html
Gotta fix that leak or figure out where it's coming from.

 

[jrod_okc]

^ Yea i know.. But from the no heat, i thought sure fire it was thermostat. fan does come on.. I am going to tear into in Thrusday.

^ Random Question... Did you have a VR4 at one time?

 

[JonB]

No / sporadic heater flow means LOW COOLANT due to air trapped in the motor, from leaks or neglect (not knowing how to routinely burp air.....)

You say there is coolant spray underhood, that will be found when coolant is FULL and HOT. Probably a hose-clamp. Mechanical leakers like water pump or T/C cover wont 'spray', hoses do that. Is it concentrated front or rear?

You know how to call me!

 

[jrod_okc]

thanks for the Info Guys.. I think i may have found the problem.. I have a aftermarket radiator hose that has the vent built in.. Seems like most of the "spray" is coming from that area.

 

[dave6666]

If it is the old Schrader type it may be the valve. the newer thumbscrew type it may be the screw loose. Or it may be the assembly into the hose itself. Sean Roe has a new kit for that.

 

[Neil - UK]

wonder if it a Roe hose, have read a few stories about them leaking at the bleed valve

 

[jrod_okc]

i found a picture of the exact coolant hose i have one here.

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[speedracervr4]

^ Yea i know.. But from the no heat, i thought sure fire it was thermostat. fan does come on.. I am going to tear into in Thrusday.

^ Random Question... Did you have a VR4 at one time?

Yea I have a 16G built 95 VR4 and my dad has two others. 542AWHP @ 18lbs of boost is what it dynoed. Would have pushed it higher, but I was getting spark blow out. I've seen your build on 3si..Good job!! My screen name is mckeandvr4 on 3si and ICPREY on 3sgto. I like the vr4s, but they doesn't compare to my Supercharged Viper. Give Sean at Roe racing a call to see if he can get you a replacement valve or a new hose.

 

[Steve-Indy]

IF it is leaking from the bleeder valve in the radiator return ("upper") hose, here's Sean Roe's fix:

Upper Radiator Hose Bleeder Kit, 1996-2002 Viper (excl 96 RT/10). - Cooling System Components - Roe Racing

Also, check the water valve to the heater (BOTH the valve itself AND the hose connections) as well as the heater hoses at the rear of the engine on the passenger side.

 

[JonB]

thanks for the Info Guys.. I think i may have found the problem.. I have a aftermarket radiator hose that has the vent built in.. Seems like most of the "spray" is coming from that area.

You found a known-culprit, but the problem is NOT ENUF COOLANT in the motor. A full surge tanks means nothing. AIR is trapped in the upper motor, and MUST get burped out. Hot air EXPANDS infinitely, hot water does not. Expanding air has been pushing your coolant out. And those leak-prone valves are NOT at the highest point of the coolant, so dont do the job completely.

 

[dave6666]

Nice pic of my car LOL. Try tightening the screw first then the body below the screw into the hose.

i found a picture of the exact coolant hose i have one here.

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[jrod_okc]

ok will do.. I searched and i came up with exactley what i had.. LOL Clean engine bay!

 

[jrod_okc]

Ok, well after a 20min talk with Jon B walking me threw how to correctly burp the coolant system(Great help btw) It is not air in the coolant system. So i am going to revert back to the Thermostat. I will be ordering one today and hope that fix's the issue.

 

[Ratical2]

You might want to order intake gaskets as well since you will have to remove the intake manifold to replace the Thermostat. Some say they are reusable if you are careful, others (the Wizard himself) say to replace them.
Check out the illustrated section to see a how to guide.

Good luck!

 

[99 R/T 10]

Get a lower temp thermo. While driving, the engine will be much cooler.

 

[Neil - UK]

have you done the water pump test mentioned in the service manual yet ?

my 2000 had fluctuating temperatures and it was the usual broken plastic impeller on the pump