HOT..................HOT.......................AIR

[FASTFUN]

I Live in AZ it is hot..........yes I know a dry heat.
Today I had the viper out in traffic 110+ out side.
Coolant temp @ 225-230.
The air conditioning compressor seemed to stop working.
Is there a thermal cut off for the compressor at a certain coolant temp.?
I will let it cool down and try it later.

Please advise.

 

[DSR207]

Mine did that last week while stuck in traffic 90+ temp, but once I got on the HWY it started working (CATCHING UP) again.

 

[Skip White]

You said, "please advise" and I will.

These cars are really not ideal to run in extreme hot weather. I'm surprised the temp went as high as it did.

My advice is to not run the car in this kind of heat, especially with the air on, and in slow moving traffic. I'm from Texas, and it just seems to take the life out of a car running in that kind of heat. At least do this as seldom as possible

I hardly ever drove any of my Vipers in the Texas miday summer heat, with the air on.

All modern A/C units have a thermal cutoff, when the head pressure builds up in the system. Good thing they do. GM started this many years ago. They called it a heat switch.

Viper's build up trememdous heat when running at a low MPH.

Low RPM really doe's not seem to matter, but MPH doe's cool the cars down. This tells me they lack air flow, as many of us have noticed how cool the temp is when traveling past 55 vs bumper to bumper traffic.

My car runs about 180-185 in the evening at 55 MPH or more in fifth gear.

It runs 205 in traffic, unless it's very cold out, then it will stay cooler.

This tells me we need a better fan system, or at least a device to kick it on earlier. Even then I'm not sure it would drop. You know the thermal sensor has the clycle of about 15 degrees, so the fan won't kick on till it's very hot.

Your car is running hotter than it may have should, as I've been caught out in the traffic mid day summer and never went this high.

Air pockets in sytem????

 

[edretti]

Yes, as with most cars the computer cuts the compressor off when the engine reaches a certain temperature in order to keep the vehicle from overheating.

 

[Skip White]

Correct on the above, and the head pressure in the A/C rises much to high also. This can destroy the compressor.

The A/C coil in the front of the radiator must shed it's heat, and 110 degree heat slow traffic, will not allow this to happen.

I swear I hate what all an A/C doe's to a car. Most people only think about the drag from the compressor. What about the trememdous heat the condensor coil in front of the rad. develops, only to be pushed into the radiator, and engine compartment. The electric clutch pulls ******* the alternator creating more heat and drag, the weight of the complete system. Don't forget the fact that if the A/C is on, and you do sprint up to 6200 RPM, this is very ******* the compressor, not to mention the drag you have going on at that speed.

I just don't run it, unless I'm just traveling from point A to B never when I'm cruising and enjoying the sensation of the car.

Roll your window's down and shut it off. It actually distracts me from the enjoyment of the car.

 

[Racer Robbie]

You are so right Skip. Also the oil cooler is bypassed when the A/C is running, at least on my 2003. They did this on account of the oil cooler being out in front and if it was not bypassed then the hot air from it would be passing through the radiator and the condensor coil making the A/C useless.
Have you seen or tried colder thermostats for the 2003 cars? Dodge only offers one for 2002 and older.

 

[Skip White]

The SRT must already have a cooler thermostat, as the car will run around 180 on the expressway in cool weather, but the temp sensor cooling cycle will allow the temp to run much higher before kicking on the varible speed hydro. fan.

The fact that the car holds steady in the 180's is proof the car has a thermostat of this temp range. I'm not so sure if you did override the temp sensor on the fan, that the car would cool down to 180 in town. The radiator is just to big for the cooling system to have enough coolant velocity at low speed. An improved water pump or an electric helper water pump may very well cool the car down. A smaller radiator may help, but then this would be counter productive in bumper to bumper traffic.

I should work on this project.

 

[GT40DOC]

Mine did the very same thing 2 days ago when the ambiant temp(in shade) was 110F and I was in traffic. My temp got up to 235-240 on the gauge. I was cooking on the inside since it had never done this before. Is there a way to get the high speed fan to come on before 218F? I live in So. Az. and it is "bugger hot" even in the evening time.

 

[Skip White]

No way I'd want the car getting that hot. That's only a few degrees from outright destruction. Makes ya wonder if it's doing some kinda damage. All aluminum engine's don't like overheating. They disipate heat better but I do know there tolorance to overheating is less.

I would rather an overide switch in the car to engage the fan when I want or a timer possibly. I do know the fan doe's have a multi speed to it, as it runs at different speeds. It's that cycle temp range that's the problem. It's very broad.

 

[FASTFUN]

The gauge shows hot at 260. The c5 corvette runs all day long at 240.
Any Viper tecs know about this one?

 

[Skip White]

The gauge shows hot at 260, and as we all know it's all over at about that temp. No way I want to be running around at 240F

Wonder at what temp the coolant mixed at 50-50 boils.

I personally like to run the coolant at 75/25 mixture as more water and less coolant run a bit cooler. If the car is getting this hot, you could not run this mixture as it would overfill the overflow.

 

[Kelly06]

Is it any harder on the engine if you drive with the AC in the "Max" setting?

 

[Skip White]

No, the Max setting on any A/C is to shut off all fresh air blending in with the recirculated air. All cars allow about 5% fresh air to come in with the A/C on, but the Max control shuts this off. Some cars,(import) show a drawing of a car with the air flowing in from outside, or another pic. of the air being recirculated. This recirc. button is Max air. On older cars the fan would also engage to high speed. Nothing in the system changes. By the way, compressors run all the time regardless of the setting or temp control position. When the little snowflake is on, the compressor is on also.

I do not recommend Max air to be run on any car unless your trying to cool it down quickly. Smokers should never run this, as the evap. coil becomes tainted when the system is on max, with no fresh air purging it clean.

Cars will get colder on Max or recirc. as the car recirculates the same stale air.

 

[edretti]

I agree with him but also NEVER leave the car on max after you turn the car off especially if the car is going to sit awhile. If you do, the condensation ends up turning moldy because there is no air circulation. You should turn the knob to either off or take it off of max on any car.

 

[Viper X]

Hey Skip,

Are there any aftermarket dual electric fan set ups that might work? It sure would be nice to be able to switch them on when we need it.

Also, how about an electric water pump or water pump assist as you said? This could put more water through the radiator and in combination with a dual electric fan setup, this could help.

Let us know.

Regards,

Dan

 

[Skip White]

There are many high quality electric fans on the market, with every kind of thermal triggering device imaginable.

Any of you guys ever heard of Tommy Fudge, his car was number one at the V-10 Nationals last year. He runs an electric in line pump on his car. He said it runs cool as a cucumber.

Steawart makes this pump, and they are around $400.00

I've seen them work in a demonstration at the PRI show. They are great. I should get one and try it.

As for electric fans, maybe we should keep the hydro fan, and try to overide the speed control and temp sensor.

It is nicely mounted in the front of the rad, and it's a good size fan, but then again, seems like Rick Maxwell from Woodhouse said they yank them out of the Comp Coupe. Can't remember, I'll ask him.

 

[GT40DOC]

I believe that PhoenixGTS member put in a 3 pass radiator and a smaller waterpump pulley with good results. I was hoping that he would join in on this thread, in that, he lives and drives in this inferno. Now come Dec.-March, it is paradise!!! Maybe I should quit ********, and just limit my viper driving during these months, like I have to do with the Pantera.

 

[Roadrunner]

This will sound counter intuitive... but give this a try...

I took a trip through Death Valley in an 03 Viper two years back... it was 122F out. The A/C quit (and yes the head pressure was too high and the compressor kicked out). So I dialed back the blower fan two notches, and the head pressure dropped enough to allow the compressor to begin operating again, and then slowly I was able to work up to the second to top notch.

This was with the top up and A/C in recirc floor/face. Once it got a chance to catch up, it worked well all day running from Scotty's Castle to Dante's view and stopping even in stovepipe wells.

Higher A/C fan speeds equal heat heat absorption in the evaporator, and higher heat rejection for the condensor (which is also heat into the air that eventually reaches the radiator). So if you can bear to lessen the load for a bit, the car (actually any car for that matter) will reward in the end.

 

[FASTFUN]

This will sound counter intuitive... but give this a try...

I took a trip through Death Valley in an 03 Viper two years back... it was 122F out. The A/C quit (and yes the head pressure was too high and the compressor kicked out). So I dialed back the blower fan two notches, and the head pressure dropped enough to allow the compressor to begin operating again, and then slowly I was able to work up to the second to top notch.

This was with the top up and A/C in recirc floor/face. Once it got a chance to catch up, it worked well all day running from Scotty's Castle to Dante's view and stopping even in stovepipe wells.

Higher A/C fan speeds equal heat heat absorption in the evaporator, and higher heat rejection for the condensor (which is also heat into the air that eventually reaches the radiator). So if you can bear to lessen the load for a bit, the car (actually any car for that matter) will reward in the end.

And I bet the car still runs fantastic!

 

[Viper X]

Hey Skip,

Any info / website on that Steawart assist fan? Where would you install it, etc. Expected results?

Thanks,

Dan

 

[Skip White]

Dan it's a Steawart assist water pump. It goes in line to the main radiator hose. Very well made, and very effective as I've seen. Makes a lot of sense how it works. I'll get my catalog and get some more info on it.

I'd like to get in touch with Tommy Fudge, as he has this unit on his super fast 96 GTS. If anyone knows how to get in touch with him, please let me know.

 

[Dawg2Snake]

It's been 115 this past week. My Snake still cools down, traffic or not. In fact, I have been impressed with it's ability to cool off considering the engine heat. My gauge reads 240 as well. Maybe my heat switch is different...

 

[FASTFUN]

It's been 115 this past week. My Snake still cools down, traffic or not. In fact, I have been impressed with it's ability to cool off considering the engine heat. My gauge reads 240 as well. Maybe my heat switch is different...

Thanks for the feedback...............I will have Eddie Martin aka Mr. Viper from Bill Luke dodge ck. it out. Has it affected the why the car runs in the long run as some of the above posts suggest.

 

[PDCjonny]

Ya know, you wouldn't be having this heat wave out there if you hadn't made so much fun of us northeasteners last winter. Remember us ******** about snowstorm after snowstorm while you guys were cruising ******* in the 70 degrees?? Neener neener...

 

[FASTFUN]

Ya know, you wouldn't be having this heat wave out there if you hadn't made so much fun of us northeasteners last winter. Remember us ******** about snowstorm after snowstorm while you guys were cruising ******* in the 70 degrees?? Neener neener...

We'll talk in the winter 70-75 every day and 350 days of sunshine........I left NY in 1988 and never looked back..........enjoy the summer!