Running Too Hot 280F Oil 250F Coolant

[sadil]

Hey guys, I was wondering if someone has had issues with overheating. I have the Arrow Tune with Pirelli slicks. Car is hitting 280F oil and 250F coolant. Not sure what is going on or if someone else has also experienced this but it never ran this hot before on the track. I did go off into the grass last time I was at the track at the end of May. I came out of the grass with a rock stuck in one of my fans. Got it out but didn’t see any other damage. And now this overheating was occurring same track 3 weeks after. Ambient was 80-95F on the days it was overheating. Just wondering if anyone has dealt with this on the east coast.

ACR record at Grattan is 1:22 flat. I’m at 1:23.3 now with my TA1 with pads, fluid, and used Pirelli slicks (20+ heat cycles after buying used) along with Arrow tune. Running 325 square and with passenger car is 3800 lbs. Having a blast trying to chase the 1:22 time down.

[99RT10]

Check to see if the fan is working, blown fuse?

[sadil]

I thought a fan that was not running would cause a CEL.

[ViperGeorge]

On track your fans aren't doing anything. They are really meant for lower RPM driving. At speed the air is being forced through radiator. You don't say which model car you have. ACRs tend to cool better because the large splitter forces more air through radiator. My TA 2.0 would regularly hit 243 cooland and 265 oil. Dick Winkles says the car is ok up to about 250-255 but it will be pulling timing. Some suggestions. Blast radiator with water from inside out to make sure it is not clogged with debris and grass, Add Water Weter. Add a spring in top radiator hose to prevent collapse under high RPMs. Remove hood vents. Install an underdrive pulley from IPSCO.ORG, it should help if the pump is cavitating. Shift sooner so as not to buzz the motor so high.

There are several threads on here about this issue. I believe the original owner of Blue TA #1 fought this issue on many fronts and I think he made some progress with a new water pumped whose tolerances were verified by Prefix.

[sadil]

George, it is just a regular TA1

Thank you for the detailed notes. I did reach out to PREFIX as well and Dick said the same thing about cleaning out the rad area and potential issues with the coolant pump cavitation.

I will remove the bumper and inspect everything. I will also be adding an ACR style splitter so that should help to get some HP air into the rad.

Any photos of the spring you mentioned? What is this?

[Steve M]

George, it is just a regular TA1

Thank you for the detailed notes. I did reach out to PREFIX as well and Dick said the same thing about cleaning out the rad area and potential issues with the coolant pump cavitation.

I will remove the bumper and inspect everything. I will also be adding an ACR style splitter so that should help to get some HP air into the rad.

Any photos of the spring you mentioned? What is this?

The spring is to prevent this:


https://www.youtube.com/watch?v=UYfmcfd_Ec0

A little more info in this thread: https://driveviper.com/forums/threads/4585-Radiator-Hose-Collapse

[Steve-Indy]

They are usually catalogued as radiator hose "support springs" or "support coils".

To see the products, go Summit Racing and search.

[Jack B]

AZ Viper has solved the cooling issues. He would be a good source for input.

[1ststrike]

I had cooling issues on my ACRE and went back to factory controller instead of Arrow controller and it took care of the issue.

[TrackAire]

If you do need to blow out the radiator stack due to ingestion of debris, this is by far the best device I've found and used:
https://www.radiatorgenie.com/radiator_genie_s/46.htm

One word of caution, if blowing between heat exchangers (like between the radiator and A/C condenser), the air wand provides so much velocity it pushes back with a lot of energy so hold it firmly to avoid it pushing it into the fins of the other heat exchanger.

I tried making my own air wands of different designs over the years and nothing, I mean nothing comes close to the air velocity this Radiator Genie produces.

[Arizona Vipers]

Hey guys, I was wondering if someone has had issues with overheating. I have the Arrow Tune with Pirelli slicks. Car is hitting 280F oil and 250F coolant. Not sure what is going on or if someone else has also experienced this but it never ran this hot before on the track. I did go off into the grass last time I was at the track at the end of May. I came out of the grass with a rock stuck in one of my fans. Got it out but didn’t see any other damage. And now this overheating was occurring same track 3 weeks after. Ambient was 80-95F on the days it was overheating. Just wondering if anyone has dealt with this on the east coast.

ACR record at Grattan is 1:22 flat. I’m at 1:23.3 now with my TA1 with pads, fluid, and used Pirelli slicks (20+ heat cycles after buying used) along with Arrow tune. Running 325 square and with passenger car is 3800 lbs. Having a blast trying to chase the 1:22 time down.

On this particular track where your oil got to 280, are you mostly in 2nd or 3rd gear?

[98intrigue]

I had cooling issues on my ACRE and went back to factory controller instead of Arrow controller and it took care of the issue.

I was going to suggest swapping back to the OEM PCM. I've seen numerous reports where the Arrow PCM was the culprit.

[nwa_viper]

I’m running the Arrow PCM and it does run hotter than factory but I always do a few cool down laps when the coolant gauge starts flashing red at 240. I mainly get this hot when using lower gears and reving higher vs one gear higher and lower rpms.

[sadil]

I was going to suggest swapping back to the OEM PCM. I've seen numerous reports were the Arrow PCM was the culprit.

Sad to hear this. Not acceptable. It is so much fun on the street.


On this particular track where your oil got to 280, are you mostly in 2nd or 3rd gear?

Hey AZ, yes the entire track mostly 2/3.

If we were to get technical, 70% 2nd, 25% 3rd, and 5% 4th (just on main straight).

Track is Grattan Raceway in Michigan.


I’m running the Arrow PCM and it does run hotter than factory but I always do a few cool down laps when the coolant gauge starts flashing red at 240. I mainly get this hot when using lower gears and reving higher vs one gear higher and lower rpms.

I didn’t get a flash. And yep low gears are all I use at the smaller local tracks.


If you do need to blow out the radiator stack due to ingestion of debris, this is by far the best device I've found and used:
https://www.radiatorgenie.com/radiator_genie_s/46.htm

One word of caution, if blowing between heat exchangers (like between the radiator and A/C condenser), the air wand provides so much velocity it pushes back with a lot of energy so hold it firmly to avoid it pushing it into the fins of the other heat exchanger.

I tried making my own air wands of different designs over the years and nothing, I mean nothing comes close to the air velocity this Radiator Genie produces.

Will look into it!


I had cooling issues on my ACRE and went back to factory controller instead of Arrow controller and it took care of the issue.

Sad to hear the controller can’t handle some simple tracking.

[Topplayer]

I have seen people modify the grill and it helped a lot, The plastic grill adds a lot of restriction to the flow up front. Also removing the hood vents help. Keep an eye on the Rad hose if it is collapsing it could be causing problems too!

Best ideas if you want to keep the Arrow

[ViperGeorge]

I had done back to back testing at the track on my TA 2.0. With the Arrow controller and with the stock controller. Same day, same ambient temps. I noticed NO difference in temps. Dick Winkles said he did not believe the controller would contribute much to the heat issue. He did suggest going with a higher pressure radiator cap which I have done on my ACR-E. On the ACR I rarely see 220 coolant on track. You should insulate the cooling lines that go to the oil cooler as well, they are close to exhaust manifolds and any heat they absorb goes to the oil cooler which can heat the oil which in turns heats the coolant. I would also insulate the wiring harness going to the fuse box. At those temps things can start to get melty.

[txA&M08]

I had headers and Arrow PCM installed, went to the track in 90 degree ambient (in Houston), and immediately saw much higher temps. Highest I read was 265 oil and 245 coolant, or thereabouts. The car felt like it was making about 350 hp at that temperature. It sounds like the Arrow PCM is one of the main culprits, but I like it too much on the street to take it off, so I will probably run through all the other suggestions first, short of hacking my grille out.

[Arizona Vipers]

Sad to hear this. Not acceptable. It is so much fun on the street.



Hey AZ, yes the entire track mostly 2/3.

If we were to get technical, 70% 2nd, 25% 3rd, and 5% 4th (just on main straight).

Track is Grattan Raceway in Michigan.



If you're running full sessions, mostly in 2nd gear and are pushing the car hard it's going to overheat like this. Tracks where you are in 3rd more than 2nd you won't have this problem at all. I solved it, but had to remove my air conditioning condenser and have a 160 thermostat and fans come on at 160 as well. The problem is your sitting on grid at 210 coolant, so your first lap you are already 50* higher than I am. Towards the end of a full session I'm about 250 coolant, 260 oil. If I wasn't running the 160 thermo and fans, I'd hit that much sooner in the session and have to pull off. I'm pretty sure you can send your PCM to Prefix and have them turn the fans on sooner and run the 160* thermostat, you'll be 50 degrees ahead of the game on your first lap.

[Simms]

Good info in here. I've seen variations of all these suggestions on Gen V's at the track.

[LuvSpeed]

This is timely information as I was hitting 240 coolant temps on the track this weekend at High Plains Raceway. I started short shifting which helped hold and lower the temps a bit. I did take off the hood vents which I think helped a bit, but still hit 240 coolant on one of my sessions. Started hitting those temps about 15 minutes into a session.

[sadil]

I have seen people modify the grill and it helped a lot, The plastic grill adds a lot of restriction to the flow up front. Also removing the hood vents help. Keep an eye on the Rad hose if it is collapsing it could be causing problems too!

Best ideas if you want to keep the Arrow

the plastic grille also has another HD plastic grill behind it haha for the support. I dont know if removing the grill will do much. Its more of a aero cover for the bumper underneath. I do have to try removing the


I had done back to back testing at the track on my TA 2.0. With the Arrow controller and with the stock controller. Same day, same ambient temps. I noticed NO difference in temps. Dick Winkles said he did not believe the controller would contribute much to the heat issue. He did suggest going with a higher pressure radiator cap which I have done on my ACR-E. On the ACR I rarely see 220 coolant on track. You should insulate the cooling lines that go to the oil cooler as well, they are close to exhaust manifolds and any heat they absorb goes to the oil cooler which can heat the oil which in turns heats the coolant. I would also insulate the wiring harness going to the fuse box. At those temps things can start to get melty.

Agree with everything you suggested for upgrades. I definitely need to do that on my car to keep everything insulated and cooler. I was surprised I was running so hot. Will be doing headers soon so I will take the opportunity to do it right. Dick also suggested that to me as well, the high pressure rad cap. I was just concerned about the factory radiator being a crimped design instead of all aluminum. I didnt want that rupturing on me.

Are people upgrading to high pressure caps regularly in their vipers?


If you're running full sessions, mostly in 2nd gear and are pushing the car hard it's going to overheat like this. Tracks where you are in 3rd more than 2nd you won't have this problem at all. I solved it, but had to remove my air conditioning condenser and have a 160 thermostat and fans come on at 160 as well. The problem is your sitting on grid at 210 coolant, so your first lap you are already 50* higher than I am. Towards the end of a full session I'm about 250 coolant, 260 oil. If I wasn't running the 160 thermo and fans, I'd hit that much sooner in the session and have to pull off. I'm pretty sure you can send your PCM to Prefix and have them turn the fans on sooner and run the 160* thermostat, you'll be 50 degrees ahead of the game on your first lap.

Interesting, so you are just manipulating the system to give you cooling sooner so you can run the full session. For some reason I think cars should be able to run indefinitely with enough cooling for hours like in the endurance races. I thought that was why road coarse guys loved NAs. AZ you did this on the stock motor before your engine build?


This is timely information as I was hitting 240 coolant temps on the track this weekend at High Plains Raceway. I started short shifting which helped hold and lower the temps a bit. I did take off the hood vents which I think helped a bit, but still hit 240 coolant on one of my sessions. Started hitting those temps about 15 minutes into a session.

Yeah, when I had my fastest session, I hit 280F/250F on coolant at the end. I feel like the car isnt pulling anything back and just continuing to heat up.


I had headers and Arrow PCM installed, went to the track in 90 degree ambient (in Houston), and immediately saw much higher temps. Highest I read was 265 oil and 245 coolant, or thereabouts. The car felt like it was making about 350 hp at that temperature. It sounds like the Arrow PCM is one of the main culprits, but I like it too much on the street to take it off, so I will probably run through all the other suggestions first, short of hacking my grille out.

I am concerned that I didnt slow down enough to notice when running hot. That scares me. And yes, I am about to get headers and totally excited about the Arrow's sounds. Don't have enough videos to experience vicariously, so there is still excitement!

[LuvSpeed]

The other thing that I am considering is changing my coolant mixture from 50-50 antifreeze-water to 25-75 antifreeze-water. Makes sense to me since water tranfers heat better. The concern that I have is a lower boiling point for the mixture. Will have to look at some table about how much this will change. Pressurized radiator cap will help raise the boiling point though.

[GTS Dean]

Some suggestions. Blast radiator with water from inside out to make sure it is not clogged with debris and grass, Add Water Weter.

If you spend much time on track, your heat exchangers will fill with grass, seeds, bug bodies, coarse sand and tire rubber - killing thermal efficiency. I pull the radiator about every other year, blow it out with both air and water, then repeatedly drop it flat on the floor from about 1" height. All kinds of interesting things rattle out...

[Larryskillzs]

I can overheat my viper on track in 3 laps by winding the shit out of the car in 2nd and 3rd gear when it's 80+ degrees.

I'm used to tracking my TT5 S2000 and always in the upper rpm range because honda, I forget and drive the Viper in the same fashion.

I think most people over heat the viper due to driver input and outside ambient temps more then mechanical issues.

Since I had a nice flashing light at 240 for coolant when romping in it, i can now taper coolant temps by changing up driving style.

[XSnake]

Are you still running antifreeze or just straight H20? Any water wetter in your system? Take your valve cover off?

[GTS Dean]

I can overheat my viper on track in 3 laps by winding the shit out of the car in 2nd and 3rd gear when it's 80+ degrees.

Since I had a nice flashing light at 240 for coolant when romping in it, i can now taper coolant temps by changing up driving style.

That's pretty much my experience when in Time Attack mode - just drive it like my Sprint Shifter kart. When I'm out practicing, I put together track segments to use max effort, then cool it on other sections. Otherwise, I just gear up, throttle back, use the torque and work on smoothness.

[Arizona Vipers]

Take your valve cover off?

This is excellent advice as well

[ViperGeorge]

This is excellent advice as well

Come on AZ, be honest. You took yours off to save a couple of ounces not because of temps.

[ViperSRT]

Hopefully the decorative covers and not the actual valve covers. That would be quite a mess.

[Arizona Vipers]

Come on AZ, be honest. You took yours off to save a couple of ounces not because of temps.

hehe that too. Actually prefix had to take them off due to the solid cam valvetrain requiring spacers on the valve covers. I weighed them and was surpsied, heavier than I thought but I forget now. They are pretty thick/dense

[sadil]

Thanks for all the comments folks.

I will go ahead and remove the radiator to blow it off and give it a good clean and will get some fresh coolant inside. Will report back with what I find.

As for driving on the track and overheating, seems like it is common when sticking to second gear as often as I do on our short Michigan tracks. The car is just geared that way and I need to start targeting hot laps instead of running race style for 15-20 mins. I am glad I asked the question before having a failure. I will back off and drive faster for a shorter amount of time. Brakes and tires will be happy too.

Regarding some of the suggested cooling modifications, I might not need them if I change my style. Will try to find something wrong with the rad first. I have also reached out to Prefix for a 160F t-stat adjustment but not sure I want that all the time since I street the car. I won't come up to temp fast enough. The 160F might help me for sure to keep things cool before going out.

Regarding coolant, I am running how it came from the factory.

Regarding the high pressure coolant reservoir cap, what have people upgraded to?

[ellowviper]

I put a cooler t-stat in my Dakota and now I get a P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature). Just saying....

[Tamvette]

Changing the thermostat will just delay it and you can damage your car if you drive in street significant miles. I thought we had slow tracks around here, 75% 2nd gear is crazy but sounds fun. For the tracks around here l, I almost always hit 240-250 oil temps and 200 - 208 coolant temp at race pace with ambient temp being 40 to 80 F.

What engine oil do you use? The thickness plays a huge role as well. As you suggested, I would change coolant mixture as well. Do you have aftermarket headers installed? I would go back to stock on that if you do.

Next step could simply be changing the gearing to suit this track better but that is obviously an extreme step. Or you could always hunt down cooler days, do you know what under what conditions the record was set?

[Arizona Vipers]

Thanks for all the comments folks.

I will go ahead and remove the radiator to blow it off and give it a good clean and will get some fresh coolant inside. Will report back with what I find.

As for driving on the track and overheating, seems like it is common when sticking to second gear as often as I do on our short Michigan tracks. The car is just geared that way and I need to start targeting hot laps instead of running race style for 15-20 mins. I am glad I asked the question before having a failure. I will back off and drive faster for a shorter amount of time. Brakes and tires will be happy too.

Regarding some of the suggested cooling modifications, I might not need them if I change my style. Will try to find something wrong with the rad first. I have also reached out to Prefix for a 160F t-stat adjustment but not sure I want that all the time since I street the car. I won't come up to temp fast enough. The 160F might help me for sure to keep things cool before going out.

Regarding coolant, I am running how it came from the factory.

Regarding the high pressure coolant reservoir cap, what have people upgraded to?


Since you drive it on the street a lot, maybe go with a 180*? And still have Prefix change the fan speed to 180* as well. You'll be 30* cooler on your first lap. And correct I think all fast drivers on 2nd gear mostly short tracks will run hot. 3rd gear these cars run ice cold.

[sadil]

Changing the thermostat will just delay it and you can damage your car if you drive in street significant miles. I thought we had slow tracks around here, 75% 2nd gear is crazy but sounds fun. For the tracks around here l, I almost always hit 240-250 coolant temps at race pace with ambient temp being 40 to 80 F.

What engine oil do you use? The thickness plays a huge role as well. As you suggested, I would change coolant mixture as well. Do you have aftermarket headers installed? I would go back to stock on that if you do.

Next step could simply be changing the gearing to suit this track better but that is obviously an extreme step. Or you could always hunt down cooler days, do you know what under what conditions the record was set?

Thank you for the insight. I am a little more comfortable now knowing that other people are also hitting these temperatures. You definitely have to drive hard to get there. I only got to this point after going to used slicks, brembo htc brake fluid, and raybestos ST47 brake pads. Arrow tune is there too but some have said it doesn't matter and I am starting to believe it. Its a big motor that will overheat with the excessive 2nd gear usage. Funny thing is that this was me actually strategically using more 3rd in the twisties!

Here is Ralph running a super quick lap in Storm. On Hoosiers he was 1:22.5 (ACR record is 1:22.1)

You can see him running 2nd for a majority of the lap along with the rev limiter jump.

https://www.youtube.com/watch?v=autrPigRodw

I only run 15W50 on the track. I am a development engineer at GM so oil is my life and it was easy to notice the advantage of going to 15W50. Cant beat the price too with Walmart Roll Back! 5Qt for $22!

I dont have my headers installed...yet! Hopefully its an issue I can solve without avoiding my header install. That would be bummer :(


Since you drive it on the street a lot, maybe go with a 180*? And still have Prefix change the fan speed to 180* as well. You'll be 30* cooler on your first lap. And correct I think all fast drivers on 2nd gear mostly short tracks will run hot. 3rd gear these cars run ice cold.

Agreed, its Grattan Raceway specifically due to the tight turns for more than half the track. Gingerman is another track I am going to in a few months. Will be great to see how the car does there at my current pace. I am thinking I won't have any issues due to more time in 3rd.

And I will definitely inquire about the fan. I actually had a typo in my post,

I have also reached out to Prefix for a 160F t-stat adjustment but not sure I want that all the time since I street the car. I won't come up to temp fast enough. The 160F (meant to write FAN SETTING) might help me for sure to keep things cool before going out.

Will try to get the fan to come on earlier for sure!


I put a cooler t-stat in my Dakota and now I get a P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature). Just saying....

Makes sense. System would recognize it as a potential issue if you just put the t-stat in without updating the sensor alarm for t-stat opening temperature.

[ViperGeorge]

Thank you for the insight. I am a little more comfortable now knowing that other people are also hitting these temperatures. You definitely have to drive hard to get there. I only got to this point after going to used slicks, brembo htc brake fluid, and raybestos ST47 brake pads. Arrow tune is there too but some have said it doesn't matter and I am starting to believe it. Its a big motor that will overheat with the excessive 2nd gear usage. Funny thing is that this was me actually strategically using more 3rd in the twisties!

Here is Ralph running a super quick lap in Storm. On Hoosiers he was 1:22.5 (ACR record is 1:22.1)

You can see him running 2nd for a majority of the lap along with the rev limiter jump.

https://www.youtube.com/watch?v=autrPigRodw

I only run 15W50 on the track. I am a development engineer at GM so oil is my life and it was easy to notice the advantage of going to 15W50. Cant beat the price too with Walmart Roll Back! 5Qt for $22!

I dont have my headers installed...yet! Hopefully its an issue I can solve without avoiding my header install. That would be bummer :(



Agreed, its Grattan Raceway specifically due to the tight turns for more than half the track. Gingerman is another track I am going to in a few months. Will be great to see how the car does there at my current pace. I am thinking I won't have any issues due to more time in 3rd.

And I will definitely inquire about the fan. I actually had a typo in my post,

I have also reached out to Prefix for a 160F t-stat adjustment but not sure I want that all the time since I street the car. I won't come up to temp fast enough. The 160F (meant to write FAN SETTING) might help me for sure to keep things cool before going out.

Will try to get the fan to come on earlier for sure!



Makes sense. System would recognize it as a potential issue if you just put the t-stat in without updating the sensor alarm for t-stat opening temperature.

If you put headers on send them to Swain for their coating first. Amazing how cool the primaries are with their coating. Coming off track and checking primary temps with a laser Pyrometer I haven't seen temps above 175 degrees on the primary tubes. That's plain crazy low for exhaust primary pipes. My friend and I both have 9 liter motors with ARH headers and we both Swain coated them. Both of us have similar readings on the primary pipes coming off track.