Cures for Gen 1 and Gen 2 Vipers running to hot!

[Daniel Cragin/DC Performance Inc]

Over the years we have had many complaints that the Viper runs to hot. According to
the service manual 230-240 degrees in stop and go driving or track use is normal, predictable and part of the personality of the vehicle. The fact is if it does not boil over then its not overheating, right ?, well sort of. The Viper engine is built to take 240 degrees on a regular basis but that does not mean it is good for performance or long
term durability. Yes, they run the engine hot for emissions but thats not the real cause, its airflow. We have been working with this problem since the first 1992 Viper came out. You have to get the air in and out of the engine area.

We have developed packages for both our race cars and street cars that take care of this problem once and for all. Some are easy and some are more complex. First make sure your cooling system is working right ( there are about 5 or six things that can cause a big problem depending on the year model). Race applications take a different approach while street applications are more simple.

For information on cooling system upgrades please feel free to contact us about your specific application.

 

[Vip-RT10]

I have a GenI and upgraded the radiator (from Elite Motorsports) with a 4 core instead of the 2 core, put a 180 thermostat, silicone hoses with a bleeder ******, Water Wetter, and a Penske radiator flushing fitting on the highest part of the cooling system to better bleed the system.
I also have a Sean Roe fan kit and the car runs cooler. The only problem I have is that from the conversion from a GenI motor to a GenII motor, the water temp sensor. I had to put it on the left and front side of the engine (drivers side) where the first bolt of the header is. This transfers a lot of heat from the block to the sensor. I even made a shield out of aluminium and applied header wrap on both side of it. This helded minimally, but I have nowhere else to put the sensor. It goes to the red on the gauge, but I stop and the Roe fan doesn't even kick in, so this means that it is still cool enough that the sensor doesn't turn on the fan. When I do sit there longer, then the fan kick on. I know that I am safe this way. Any sugestions that doesn't involve tapping a new hole in the block?

 

[Jack B]

I don't know what you by "had to", however, the sensor on the drivers side in a Gen I is the high temp alarm.

 

[Vip-RT10]

Had to because the wiring was way short and the location of the sensor on the original engine was in a different place. So it is called the "high temp alarm", and it gets hotter than it should where it is. Stil looking for a better place for it.

 

[sun diego]

Dan, could you please post the "5 or 6 things" to check that our cooling systems are working right?

 

[Daniel Cragin/DC Performance Inc]

Here is what to check for on Gen 1 and Gen 2 Vipers before
making cooling system upgrades.

GEN 1
Check rear crossover gaskets and head gaskets for leaking
Check gauge reading with actual temp (a scanner helps), many Gen 1 cars had inaccurate gauges.

GEN 2
Check water pump impeller shaft for slipping.
Inspect high speed fan relay for signs of overheating.
Front timing cover gaskets on early Gen 2's sometimes
leak coolant into the oil, if coolant is getting into your
oil remove the oil pan and look up at the gasket to see if it is leaking. Do not just assume it is a head gasket.

All Models:
Perform a "block check" to make sure no hydrocarbons are exscaping into the coolant.

Check for leaves and foriegn objects between radiator and
oil cooler. (if you have gone off the track you may have
a farm in your grill)

Inspect fan for rubbing (on bottom ) or loose shaft.
Check high and low fan speed operation.

Pressure check cooling system for leaks. Check around radiator tank and heater hoses including the heater core and heater valve.

Check cap for proper release.

Inspect overflow tank (in fender) for cracks and proper
fill.

Check Thermostat operation and bleed all air from system. A
air bubble will cause a thermostat to stick closed.

Check coolant mix, never run more than 50/50. One gallon coolant to 3 gallons distilled water and 2 water wetters
makes a big differance. Never run straight water as the resulting corrosion can ruin an engine.