Ulysses
Enthusiast
In short, a thermostat alone will not help.
Effect of 190* Thermostat?
- Thread starter Ulysses
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No. Unless it's stuck look other areas for an overheating cause/fix.
The Mopar unit is 180*. If the 195* t-stat is open and the car runs 240* then you put in a 180* t-stat, the car will still run 240*. The lower T-stat WILL result in lower engine temps on a cold morning, on the highway. Maybe lower than you want it to run.
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by AQX:
So will using a 190* thermostat alone - without any othermodifications to the car, such as bigger radiator,
etc. - help the car to endure hotter weather and
avoid overheating? Thanks for any advice!
Michael <HR></BLOCKQUOTE>
The Mopar unit is 180*. If the 195* t-stat is open and the car runs 240* then you put in a 180* t-stat, the car will still run 240*. The lower T-stat WILL result in lower engine temps on a cold morning, on the highway. Maybe lower than you want it to run.
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by AQX:
So will using a 190* thermostat alone - without any othermodifications to the car, such as bigger radiator,
etc. - help the car to endure hotter weather and
avoid overheating? Thanks for any advice!
Michael <HR></BLOCKQUOTE>
Chuck 98 RT/10
Enthusiast
You're in San Fran? Wait to see if it over heats. It may only need burping.
I'm in Tampa and have never experienced my stock 98 RT/10 overheating in 40K+ miles.
I'm in Tampa and have never experienced my stock 98 RT/10 overheating in 40K+ miles.
red98GTS
Enthusiast
What Marv said.
Vic
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All the thermostat does is keep the coolant circulating in the block alone, (for fast warmup), until the coolant reaches the thermostat temp set point, then it opens up, and allows the coolant to flow through the radiator. Changing the thermostat will only change the point at which the flow is allowed to go through the radiator. Once its open, the temp continues to climb, and it stays open from there on out. It won't shut again until the car is parked, and cools off to below the thermostat set point value.
The thermostat has no effect on when (what temp) the cooling fans turn on, this is controlled by the computer. To change this, you need to change the EPROM chip in the computer, I'm pretty sure. Most of my experiences are with other cars, but they are more alike than they are different, ya know?
Since you have a 2001, which has suspect water pump impellers, that can come loose from the shaft, then I suggest you take a pre-emptive "strike" (no pun intended) at this weak point by going to an aftermarket water pump. Talk to Sean Roe, or Doug Levin. Maybe Parts Rack? Thats what I am going to do.
The thermostat has no effect on when (what temp) the cooling fans turn on, this is controlled by the computer. To change this, you need to change the EPROM chip in the computer, I'm pretty sure. Most of my experiences are with other cars, but they are more alike than they are different, ya know?
Since you have a 2001, which has suspect water pump impellers, that can come loose from the shaft, then I suggest you take a pre-emptive "strike" (no pun intended) at this weak point by going to an aftermarket water pump. Talk to Sean Roe, or Doug Levin. Maybe Parts Rack? Thats what I am going to do.
Vic
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Oh, I see Marv already touched on this.
viper spray
Enthusiast
I am right in the middle of putting a 180 thermostat in my car, I had to stop due to one missing gasket. This is a ton of work for just a thermostat, R & R wipers ,cowl, 3 stuck hoses, special tool for housing,(inverted star),3 gaskets and 1 "O" ring,clean all surfaces, coolant all over the place, super glue head side gaskets on so they will not move during assembly,no room to work, will need to re-burp system...... "I hope it is worth it"
It's even more work on a Gen 2 motor
King GTS
Enthusiast
I'm having an overheating problem myself. I already have an upgraded radiator & a 180 degree thermostat. The thermostat works great on the highway when your wide open. It actaully makes the car run cooler. But in stop & go driving situations, NOTHING. My Viper Tech has burped mine as well. Nothing. Checked to make sure the fans were coming on when they were supposed to too. They are. Still gets waaay too hot! He ordered a new water pump for me that just came in today & I'm having it installed tomorrow. Supposedly Dodge switched the vendor that they were getting the water pumps from for the 2001 Vipers. There was an impellor problem w/ the 1st water pumps they used, causing the 2001's to overheat! I'll keep you posted. Last week while driving, temp gague went passed the red, AC started blowing jet HOT! Had to pull over.
Vic
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Trey, buddy...
Forgive me for taking issue with this, but....
When you say that your 180 thermostat actually makes your car run cooler, is it from your observation, or...
I can't think of one single reason why a 180 thermo would make any difference at all, anytime after warm up.
Remember, it is either open or shut. It opens above 180. Anytime your car is running above 180, (Which is all the time, unless you are driving in liquid nitrogen) the thermo is open, and fluid is allowed to flow to the radiator. If for some reason it was to shut, then the fluid couldn't get out of the block, and the coolant temp would soar.
The thermo doesn't keep the coolant at its rated temp, that's just the point at which it opens, after fast warm up. There is no way a 180 thermo couold keep your car cooler. It just doesn't work that way.
Now there is a thermostat, (not a spring loaded valve in the path of the coolant, but an electric one) that controls the point at which the fans turn on, could this be what you are referring to?
PS. That Venom is awesome! Looks real baaaaad! Congrats! Hope you sort out the temp thing soon.
Forgive me for taking issue with this, but....
When you say that your 180 thermostat actually makes your car run cooler, is it from your observation, or...
I can't think of one single reason why a 180 thermo would make any difference at all, anytime after warm up.
Remember, it is either open or shut. It opens above 180. Anytime your car is running above 180, (Which is all the time, unless you are driving in liquid nitrogen) the thermo is open, and fluid is allowed to flow to the radiator. If for some reason it was to shut, then the fluid couldn't get out of the block, and the coolant temp would soar.
The thermo doesn't keep the coolant at its rated temp, that's just the point at which it opens, after fast warm up. There is no way a 180 thermo couold keep your car cooler. It just doesn't work that way.
Now there is a thermostat, (not a spring loaded valve in the path of the coolant, but an electric one) that controls the point at which the fans turn on, could this be what you are referring to?
PS. That Venom is awesome! Looks real baaaaad! Congrats! Hope you sort out the temp thing soon.
King GTS
Enthusiast
Hey buddy. Now I'm all confused. I had overheating problems & a fellow member suggested that I upgrade my radiator, add the 180 t-stat, and 2 bottles of water wetter. When I made those changes, I saw absolutely no difference in engine operating temps except when I was wide open on the highway. My car did actually run a few degrees cooler vs. the old thermostat. I know this because I made the additions in stages. 1st added the radiator, no help. Then the water wetter..no real help, especially in this Texas heat. Then the 180 t-stat, and I noticed the difference. Without the 180 t-stat, I'd sit a hair above 220 when wide open. With it, I'm ALWAYS in the 190 range when wide open. But ONLY when I'm wide open on the highway. In stop & go, it's just like the stock t-stat. I guess I'd have to say that this is just from my personal obversations though. But I've really been through the ringer w/ this same issue w/ a 97 that I had years ago. So much that I had to sell it!
Thanks for the pos feddback on my car! I love it! Let's hope I can get the overheating issue resolved.
Thanks for the pos feddback on my car! I love it! Let's hope I can get the overheating issue resolved.
Vic
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Man alive! I hope you can get this sorted out soon, so you can enjoy your Venom without reservation.
I just got done talking with our salesman, who had a three year old car that overheated. The thermostat was stuck shut. Sometimes a shadetree mechanic can take the thermo completely out, and run it, to see if the thermo is closing partially sometimes. If it runs better, that would point to a sticky or erratic thermo. I have no personal experience with this method, but it sounds reasonable.
Also, has the radiator been power flushed? Not just the radiator, but the block as well? Is there any junk inside the radiator hoses? Have you tried any of that white stuff from Purolator, (I think thats the name, its available at Pep Boys), that you add to the coolant, run it for a while, and it breaks up corrosion? You can see lots of crap come out, when draining the system after using this stuff. That, in conjunction with a power flush, should ensure that the coolant system is free of obstructions to heat transfer. Better ask a Viper tech or a good tuner if that white stuff is kosher to put in the system.
Changing the water pump sounds like a real strong move....
How about wiring the fans on continuously, then running the car hard with the air on? If it doesn't overheat then, then that would point to a fan cycling problem. You can buy an infrared thermometer, and point it at the radiator. Start with the car cold, take continuous readings as the car warms up. Note the temp at which the fans turn on. At what temp are they turning on?
As one last ditch troubleshooting idea, (for now), I would take a 12 volt test light, wire it in parrallel with the fan motors, run it back into the cockpit, and drive the car, noting when the fans turn on and off. If they turn off while the temp is soaring under load, then there is a computer problem, or realted issue. Possibly, Dodge is using a relay to turn the fans on, upon command from the computer, and maybe that relay has contacts that are going bad. This would let the fans stop turning intermittantly.
To get into this any further, I'd have to buy the manual. Wish you the best with that beautiful car...
I just got done talking with our salesman, who had a three year old car that overheated. The thermostat was stuck shut. Sometimes a shadetree mechanic can take the thermo completely out, and run it, to see if the thermo is closing partially sometimes. If it runs better, that would point to a sticky or erratic thermo. I have no personal experience with this method, but it sounds reasonable.
Also, has the radiator been power flushed? Not just the radiator, but the block as well? Is there any junk inside the radiator hoses? Have you tried any of that white stuff from Purolator, (I think thats the name, its available at Pep Boys), that you add to the coolant, run it for a while, and it breaks up corrosion? You can see lots of crap come out, when draining the system after using this stuff. That, in conjunction with a power flush, should ensure that the coolant system is free of obstructions to heat transfer. Better ask a Viper tech or a good tuner if that white stuff is kosher to put in the system.
Changing the water pump sounds like a real strong move....
How about wiring the fans on continuously, then running the car hard with the air on? If it doesn't overheat then, then that would point to a fan cycling problem. You can buy an infrared thermometer, and point it at the radiator. Start with the car cold, take continuous readings as the car warms up. Note the temp at which the fans turn on. At what temp are they turning on?
As one last ditch troubleshooting idea, (for now), I would take a 12 volt test light, wire it in parrallel with the fan motors, run it back into the cockpit, and drive the car, noting when the fans turn on and off. If they turn off while the temp is soaring under load, then there is a computer problem, or realted issue. Possibly, Dodge is using a relay to turn the fans on, upon command from the computer, and maybe that relay has contacts that are going bad. This would let the fans stop turning intermittantly.
To get into this any further, I'd have to buy the manual. Wish you the best with that beautiful car...
Vic
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I was thinking...
You say its cooler at wide open. Thats when you are pumping maximum coolant. Lets leave that aside....
Maybe the old thermostat was getting in the way of the flow? 'Cause you DID notice a change for the better, when you changed it out....
Hmmmm....
Why don't you post back, and let us know how that new water pump works out. There's gotta be a solution to this...
You say its cooler at wide open. Thats when you are pumping maximum coolant. Lets leave that aside....
Maybe the old thermostat was getting in the way of the flow? 'Cause you DID notice a change for the better, when you changed it out....
Hmmmm....
Why don't you post back, and let us know how that new water pump works out. There's gotta be a solution to this...
Remove the t-stat from the mix and primary factors for coolant temp are air flow through the rad, ambient air temp, and engine load.
In theory (don't actually do this but visualize it): Weld the t-stat open. Run the car on the freeway at 30* and the temp will never reach even the left mark \ ! / ( a 180 will raise the temp to the left mark and a stock t-stat will raise and keep the temp about center.)
Make it 75* on the freeway, the engine has minimal load and good airflow, and the temp will run about at the left mark or between left and center \ ! / (a 180 will put the temp on the left mark and A stock t-stat will keep the temp at center)
City driving with minimal air flow and the temp will run right of center, varying with the fan operation. Neither t-stat is a factor in the temp.
The lower t-stat allows the car to run colder, to a point, but does nothing to prevent it from running too hot
In theory (don't actually do this but visualize it): Weld the t-stat open. Run the car on the freeway at 30* and the temp will never reach even the left mark \ ! / ( a 180 will raise the temp to the left mark and a stock t-stat will raise and keep the temp about center.)
Make it 75* on the freeway, the engine has minimal load and good airflow, and the temp will run about at the left mark or between left and center \ ! / (a 180 will put the temp on the left mark and A stock t-stat will keep the temp at center)
City driving with minimal air flow and the temp will run right of center, varying with the fan operation. Neither t-stat is a factor in the temp.
The lower t-stat allows the car to run colder, to a point, but does nothing to prevent it from running too hot
Doug Supercharged Vipers
Enthusiast
Great input from all of you!
Later today (if I can dig up some free time) I will lend more info for you guys to try to get some of that unwanted heat out. I've spent many hours R&D time on this subject and found excellent results I will share with you all. And it wont brake the bank
.
PS. Trey, before you change the water pump (as a general rule) see if your heater works well first. The heater circuit is a by-pass and won't work well (if not at all) if the pump impeller is defective.
Regards,
Doug Levin
Later today (if I can dig up some free time) I will lend more info for you guys to try to get some of that unwanted heat out. I've spent many hours R&D time on this subject and found excellent results I will share with you all. And it wont brake the bank
PS. Trey, before you change the water pump (as a general rule) see if your heater works well first. The heater circuit is a by-pass and won't work well (if not at all) if the pump impeller is defective.
Regards,
Doug Levin
SneakyPete
Enthusiast
KingGTS wrote:
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>
I had overheating problems & a fellow member suggested that I upgrade my radiator, add the 180 t-stat, and 2 bottles of water wetter. When I made those changes, I saw absolutely no difference in engine operating temps except when I was wide open on the highway.
<HR></BLOCKQUOTE>
Trey,
Join the club, you have the same exact symptoms that I had with my 2001 GTS. Of course I no longer have the car.
There is usually only one way to fix it.
As I remember from our other emails, you were running hot before the VENOM 650R upgrade correct?
What type mods were done to the engine with the venom 650R?
Did you ever have a water pump failure prior to running overheat condition or did it always run hot to begin with.
Let me if this happens to your car: you should notice on your car at idle and low rpm's the temp stays around 195-205 on gauge. Start driving hard and rockets to the 250 degree red area.
let me know
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>
I had overheating problems & a fellow member suggested that I upgrade my radiator, add the 180 t-stat, and 2 bottles of water wetter. When I made those changes, I saw absolutely no difference in engine operating temps except when I was wide open on the highway.
<HR></BLOCKQUOTE>
Trey,
Join the club, you have the same exact symptoms that I had with my 2001 GTS. Of course I no longer have the car.
There is usually only one way to fix it.
As I remember from our other emails, you were running hot before the VENOM 650R upgrade correct?
What type mods were done to the engine with the venom 650R?
Did you ever have a water pump failure prior to running overheat condition or did it always run hot to begin with.
Let me if this happens to your car: you should notice on your car at idle and low rpm's the temp stays around 195-205 on gauge. Start driving hard and rockets to the 250 degree red area.
let me know
shifter
Enthusiast
A couple of points guys:
1) The fan is set to come on at about 195* Top water (equivalent). With the T-stat set at 195*, there will be a lot of cycling going on with the fan and T-stat. Not good for long term reliability.
2) With a 180* T-stat, it is possible that the water temp will stabilize below 195* on cooler days, or lower loads, thus reducing the coolant temp in the heads, thus allowing the heads to run cooler (didn't say this is a benefit with aluminum, they typically like to be warmer than iron, but don't know how much).
3) The fan normally runs at vehicle speeds at/below 45 MPH or so (don't know the exact strategy from DCX, but the PCM tweaking guys probably do). This is because at vehicle speeds over 45 or so, the fan actually becomes a restriction to ram air.
So, at reduced loads or lower ambients it is possible that the 180 degree T-stat will allow the engine to run cooler for a period of time.
Also, if you are truly overheating (running 225+) then you have a mechanical problem or an inaccurate gage.
Lastly, if you put a higher capacity radiator in, or other mods to significantly increase cooling (remove Condenser, etc) on a relatively stock car, you should put in a lower T-stat. The added cooling will only get you to 195* then the T-stat will close and you are no better off than with the stock system (given no mechanical problems).
For those seriously interested or have the need, we make radiators for the majority of the Nascar teams, as well as several other teams in all types of racing. We do have a radiator (2 row aluminum) with a fan kit (stock fan won't fit on our radiator) that will add some serious cooling capacity. It is designed as a drop in. Not cheap and not needed for 90% of the Viper owners with stock engines or mild mods. You can e-mail me for details if you like. We don't advertise direct or normally sell to the general public, but exceptions are a fact of life. Again, I would caution that only very few Vipers should need more cooling capacity.
1) The fan is set to come on at about 195* Top water (equivalent). With the T-stat set at 195*, there will be a lot of cycling going on with the fan and T-stat. Not good for long term reliability.
2) With a 180* T-stat, it is possible that the water temp will stabilize below 195* on cooler days, or lower loads, thus reducing the coolant temp in the heads, thus allowing the heads to run cooler (didn't say this is a benefit with aluminum, they typically like to be warmer than iron, but don't know how much).
3) The fan normally runs at vehicle speeds at/below 45 MPH or so (don't know the exact strategy from DCX, but the PCM tweaking guys probably do). This is because at vehicle speeds over 45 or so, the fan actually becomes a restriction to ram air.
So, at reduced loads or lower ambients it is possible that the 180 degree T-stat will allow the engine to run cooler for a period of time.
Also, if you are truly overheating (running 225+) then you have a mechanical problem or an inaccurate gage.
Lastly, if you put a higher capacity radiator in, or other mods to significantly increase cooling (remove Condenser, etc) on a relatively stock car, you should put in a lower T-stat. The added cooling will only get you to 195* then the T-stat will close and you are no better off than with the stock system (given no mechanical problems).
For those seriously interested or have the need, we make radiators for the majority of the Nascar teams, as well as several other teams in all types of racing. We do have a radiator (2 row aluminum) with a fan kit (stock fan won't fit on our radiator) that will add some serious cooling capacity. It is designed as a drop in. Not cheap and not needed for 90% of the Viper owners with stock engines or mild mods. You can e-mail me for details if you like. We don't advertise direct or normally sell to the general public, but exceptions are a fact of life. Again, I would caution that only very few Vipers should need more cooling capacity.
King GTS
Enthusiast
Thanks so much for the help guys! I'm printing this thread & taking it to my Viper Tech tomorrow! Thanks also to Doug Levin for takin the time to help as well. I know I speak for EVERYONE that has this problem when I say that we'd be extremely interested in some of the R that you've done on this issue. Great to have this Board in a crisis situation!
Let me also add that the 180 Thermostat's that your dealer orders from Mopar DO NOT work unless it's modified by having holes drilled in it. It's actually "luck of the draw" if you don't have your Viper tech modify it. They've had a problem w/ them not opening at all & it actually causes your Viper to overheat!
Let me also add that the 180 Thermostat's that your dealer orders from Mopar DO NOT work unless it's modified by having holes drilled in it. It's actually "luck of the draw" if you don't have your Viper tech modify it. They've had a problem w/ them not opening at all & it actually causes your Viper to overheat!
Vic
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Oh, yeah... Did we forget about Michael?
Michael, I hope you find the solution. Can't wait to hear what Doug Levin has to say...
Marv, from your post, I can see that the thermostat CAN affect your temperature, even after warmup.
It seems that this issue is bigger than I previously thought. And many members here each have one differrent piece of the puzzle, from their experience. After Doug Levin checks back in, lets take this thread, and make a permanent addition to the board.
Michael, I hope you find the solution. Can't wait to hear what Doug Levin has to say...
Marv, from your post, I can see that the thermostat CAN affect your temperature, even after warmup.
It seems that this issue is bigger than I previously thought. And many members here each have one differrent piece of the puzzle, from their experience. After Doug Levin checks back in, lets take this thread, and make a permanent addition to the board.
viperdoctor
Enthusiast
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Vic Rough:
Remember, it is either open or shut. It opens above 180. Anytime your car is running above 180, (Which is all the time, unless you are driving in liquid nitrogen) <HR></BLOCKQUOTE>
That's not true. A thermostat is definitely opening and closing during normal driving. Keep in mind that on a hot 90degF day the ambient air is around 100 degF cooler than the desired engine coolant temperature.
So, on highway driving with all that air going across the radiator, Trey would definitely see a lower running temp with the new thermostat.
Remember, it is either open or shut. It opens above 180. Anytime your car is running above 180, (Which is all the time, unless you are driving in liquid nitrogen) <HR></BLOCKQUOTE>
That's not true. A thermostat is definitely opening and closing during normal driving. Keep in mind that on a hot 90degF day the ambient air is around 100 degF cooler than the desired engine coolant temperature.
So, on highway driving with all that air going across the radiator, Trey would definitely see a lower running temp with the new thermostat.
Tom F&L GoR
Enthusiast
Before any body tries it, please check with the service manual about the operation of the thermostat. I thought it was a "valve" in that it directs water either back to the block (when cold) or through the radiator (when hot.) Without any thermostat, the water gets to choose where to go, and would take path of least resistance, which is not necessarily the radiator. Therefore, in a marginal situation, removing the thermostat could make engine block coolant temperatures higher!
Otherwise, a thermostat is not exactly a temperature controller, it only determines how low the coolant temperature is *allowed* to go. Just like your house - if you set the furnace thermostat at 72F, it won't go below 72F in the winter, but it won't keep it at 72F in the summer.
Otherwise, a thermostat is not exactly a temperature controller, it only determines how low the coolant temperature is *allowed* to go. Just like your house - if you set the furnace thermostat at 72F, it won't go below 72F in the winter, but it won't keep it at 72F in the summer.
