overheat question

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Hi everyone,

I know the viper is kown to run very hot, but when does hot become overheat?
My car has no heat problem when I'm driving at normal speed, but in the traffic during a sunny day, it gets very hot quickly and the temperature gauge goes up.

Here's a pic of my temp gauge some days ago during an unexpected traffic jam:
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Sorry for the blurry picture. It actually went a lil hotter than that, it went up to the line between 90 and 120, I guess that is 105 ?

Is that a common behaviour for the viper or should it always stay near 90 ? Does this mean I should take the next exit and turn off the engine and let it cool off? All my other cars I owned the temp gauge never went up over 90 even in dense traffic so I really don't know if this is a big deal or not.

If not, what temperature is the emergency limit? When should I be worried about the health of my engine and should take the nearest exit and let the car cool ?

I already ordered a 180 degree thermostat, anything else I can install on my ride to avoid this? New water pump + full water system flush?

Thanks,
Jo
 

Fuoss484

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A lot of people say to check the radiator fan to make sure it is coming on. The fan relay melting in the fuse box seems to be a common problem. Also, the connection btw the fan and the engine harness, has caused problems.
 

Steve-Indy

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The year of your Viper may color my own opinion. That said, as suggested...this is a good time to test cooling system...and service as necessary.

By my calculations, 105 degrees Celsius = 221 Degrees Fahrenheit. IF this is a Gen I and the reported 105 C was the peak temp AND IF the temp came down after fan kicked on (assuming it did come on) I would not be too concerned...yet.

Is your cooling system full? How much coolant in pressure bottle and in overflow bottle? Did/does fan come on and take affect at idle as the appropriate registered temp? When starting cold, does upper radiator hose get warm at correct temp for the T-stat? Does the heater hose get warm as soon as temp rising (water valve should be open)? Does fan come on as soon as A/C turned ? Have you changed coolant regularly per factory schedule?


Is you Viper a 2000 or 2001 (or early2002)??
 

g3t_t0rk

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Driving my Roe s/c '98, I noticed this exact situation as well. Temp seems to climb fairly easy in stop and go
 

LifeIsGood

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My temp periodically climbs to match your picture...usually when no air is getting to the front of the viper. It goes back down once I'm in clean air with my foot on the gas. I don't get worried until it gets over the final notch. I was having heat problems a while back, but it turned out to be the water pump...new pump, full flush of the system and I've been good to go for a couple of years now.
 
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Thanks for your replies guys!

Sorry for posting no info about the car, it is a 2000 GTS with headers, exhausts, TBs and SCT tune. Steve-Indy I don't have all the answers for your questions but I'll defenetly take a look at everything you said in the next days. Thanks for your help! I bought the car 1 year ago, I didnt flush the cooling system yet and I dont know when the previous owner did it... :(

My temp periodically climbs to match your picture...usually when no air is getting to the front of the viper. It goes back down once I'm in clean air with my foot on the gas. I don't get worried until it gets over the final notch. I was having heat problems a while back, but it turned out to be the water pump...new pump, full flush of the system and I've been good to go for a couple of years now.

My situation is EXACTLY the same. As soon as I am in clean air and driving at "normal" street speed the temp is always at 90. Only time it goes up is when I do alot of stop and go / traffic.


Thanks everyone!
Jo
 

Fatboy 18

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Mines the same in my 2000 GTS, It will get like that in stop and go traffic. It gets that high if i have the A/C on. If i turn off the A/C it will decrease very slightly, but it always seems to sit just over that 3rd line.
My car has just hit 64k I have changed the coolant using the Mopar green antifreeze and used distilled water, I was thinking of removing the radiator and having it cleaned to remove all the built up road debris which accumulate over the years?
 

Fatboy 18

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A lot of people say to check the radiator fan to make sure it is coming on. The fan relay melting in the fuse box seems to be a common problem. Also, the connection btw the fan and the engine harness, has caused problems.
Yep I have had the Fan relay melt in my 2000 GTS I replaced the relay and there is a spare relay socket under my cover, so I now also carry a spare (just incase). :)

You need also to clean the female connections when replacing the relay as they build up carbon deposits from arcing. ;)
 

scottmarston

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Thanks for your replies guys!

Sorry for posting no info about the car, it is a 2000 GTS with headers, exhausts, TBs and SCT tune. Steve-Indy I don't have all the answers for your questions but I'll defenetly take a look at everything you said in the next days. Thanks for your help! I bought the car 1 year ago, I didnt flush the cooling system yet and I dont know when the previous owner did it... :(



My situation is EXACTLY the same. As soon as I am in clean air and driving at "normal" street speed the temp is always at 90. Only time it goes up is when I do alot of stop and go / traffic.


Thanks everyone!
Jo

Drive the car. I have a '95 and it's always hitting 225F in the summer time during stop and go. In the spring and fall, it barely touches over 180F. I worried about it until I realized that's just how this model runs. I'm driving it in 106F weather this summer and it doesn't go over 225F in the worst conditions. Not sure why everybody thinks a changing the thermostat is going to make the car run cooler. 190F...180F...the damn thing is wide open in either event during the summer. Isn't the thermostat's only purpose to allow various components to remain hot and to provide heat to the heater in your car?
 

Bugman Jeff

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Not sure why everybody thinks a changing the thermostat is going to make the car run cooler. 190F...180F...the damn thing is wide open in either event during the summer. Isn't the thermostat's only purpose to allow various components to remain hot and to provide heat to the heater in your car?
Ideally, the thermostat's main job is to maintain a constant engine temperature. If the coolant gets too cold, it starts closing, slowing water flow and raising the temp. As the coolant heats up, it opens further allowing more flow through the radiator. Overheating occurs when the thermostat is wide open, but the radiator isn't removing heat fast enough. The thermostat also allows the engine to get up to operating temp faster. It's closed when the engine is cold, allowing the coolant in the block to heat up quickly instead of circulating through the radiator cooling off still cold coolant.

Unless you have an overheat condition, a lower temp thermostat helps because the coolant doesn't have to wait as long to get to the radiator. The stock thermostat doesn't even begin to open until 195° and isn't fully open until 219°, so until 195° coolant isn't even circulating through the radiator. A 180° thermostat should be fully open by 180°, so the temp it tries to maintain is much lower, and coolant can start circulating much sooner.
 
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g3t_t0rk

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My Gen 3 was very consistent in temps so it's a bit unnerving to see the temps climb and fall in the Gen 2's. The fact that many other Gen 2's seem to have the same issue makes me think that it's just the way these cars tend to run. Guess that 3rd notch is the defining line between hot and TOO hot!
 

AZTVR

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Guess that 3rd notch is the defining line between hot and TOO hot!
Not sure which of the 8 markings you are calling the 3rd notch; but, the red area is what the factory has marked as TOO hot ! Of course, I would be nervous when it gets between the 7th and 8th marks.
 

scottmarston

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Ideally, the thermostat's main job is to maintain a constant engine temperature. If the coolant gets too cold, it starts closing, slowing water flow and raising the temp. As the coolant heats up, it opens further allowing more flow through the radiator. Overheating occurs when the thermostat is wide open, but the radiator isn't removing heat fast enough. The thermostat also allows the engine to get up to operating temp faster. It's closed when the engine is cold, allowing the coolant in the block to heat up quickly instead of circulating through the radiator cooling off still cold coolant.

Unless you have an overheat condition, a lower temp thermostat helps because the coolant doesn't have to wait as long to get to the radiator. The stock thermostat doesn't even begin to open until 195° and isn't fully open until 219°, so until 195° coolant isn't even circulating through the radiator. A 180° thermostat should be fully open by 180°, so the temp it tries to maintain is much lower, and coolant can start circulating much sooner.

I guess my argument is my car has run at 225F in the summer on the stock thermostat AND my newly installed 180F thermostat. Like you said, at 225F they are both wide open; however, I wasn't aware that the stock didn't open wide until 219F. If what you say is true about the 180F opening all the way at 180F, then I would agree with you.
 

g3t_t0rk

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Not sure which of the 8 markings you are calling the 3rd notch; but, the red area is what the factory has marked as TOO hot ! Of course, I would be nervous when it gets between the 7th and 8th marks.

I probably should've specified a bit more, but yes the 7th mark is what I meant haha
 

Fatboy 18

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Not sure which of the 8 markings you are calling the 3rd notch; but, the red area is what the factory has marked as TOO hot ! Of course, I would be nervous when it gets between the 7th and 8th marks.
I was referring to the 3 Bold central lines in the middle of the gauge ;)
 
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