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-   -   "COULD" Changing the Thermostat... (http://www.wranglerforum.com/f282/could-changing-the-thermostat-56691.html)

mcoh1030 07-30-2010 06:37 AM

"COULD" Changing the Thermostat...
 
from a 195 to a 180 cause the computer chip to adjust?

So that when the vehicle is running, it runs hotter than normal?

I've been told that putting in a 180 thermostat can effect the rate at which gas is sent into the cylinders by the computer. In my 2000 I took out the 195, breifly put in a 180, (which momentarily cuased the "check engine" light to go on when it first hit operating temp.) and then reinstalled my 195 as the 180 was a FAIL-Safe that failed almost immediately.

s3nt3nc3d 07-30-2010 08:47 AM

The 180 should cause it to run cooler than normal...and that code you threw most likely was a code for "engine running too cold for too long" which is there because our engines are designed to run around 210 degrees (using a 195 degree thermostat to achieve that) and that 180 isn't allowing the engine to warm up fully.

We used to put 180 thermostats on our Dodge Dakotas because we'd get more power out of them...our engines ran cooler, some threw codes and they had to switch thermostats (some changed brands to another 180 that seemed to open closer to 185 and others just went back to the stock 195), and many also had a noticeable drop in gas mileage.

Neil F. 07-30-2010 09:55 AM

A 180 is not going to cause a code in the TJ. A 160 may.

Note, putting in a lower temp thermostant does not mean that the engine will actually run any cooler. That is dependeant on the cooling system being able to exchange the engine generated heat.

If indeed the engine does run cooler, the computer will may richen the fuel mixture a little. It will not result in a mileage difference you will be able to see.

DevilDogDoc 07-30-2010 10:17 AM

Mine runs consistently cooler with the 180 no CEL no other issues, either ac on in the desert heat I stay between the 2 and 1 on the gauge. No ac I'm a needles width to the left of the 2.

Jerry Bransford 07-30-2010 11:32 AM

Why do some people think it is wise to install a 165 or 180 degree thermostat that opens sooner than the Jeep engineers designed the engine and programmed computer for? :confused:

I have done a LOT (!!!) of modifications to both of my TJs, wheel in the hottest desert conditions, and I still choose to run the factory recommended 195 degree thermostat. I really don't see the sense of installing a 165 or 180 degree thermostat when the factory specified 195 degree thermostat works fine.

In hot desert conditions, running a 165 or 180 degree thermostat will NOT (!!!!!!!!!!) cause the engine to run any (!) cooler. It just doesn't work that way and those that think it does are simply incorrect. A cooler thermostat will cause the engine to run cooler in very cold ambient conditions when it's of no benefit to do but not in hot conditions. And before you disagree, think about what the 165, 180, and 195 degree thermostats have all already done by the time the engine reaches its 210 temperature. ALL have already opened fully, none can flow any more water or cause the engine to cool any more efficiently in hot conditions.

DevilDogDoc 07-30-2010 12:06 PM

Quote:

Originally Posted by Jerry Bransford (Post 706588)
Why do some people think it is wise to install a 165 or 180 degree thermostat that opens sooner than the Jeep engineers designed the engine and programmed computer for? :confused:

I have done a LOT (!!!) of modifications to both of my TJs, wheel in the hottest desert conditions, and I still choose to run the factory recommended 195 degree thermostat. I really don't see the sense of installing a 165 or 180 degree thermostat when the factory specified 195 degree thermostat works fine.

In hot desert conditions, running a 165 or 180 degree thermostat will NOT (!!!!!!!!!!) cause the engine to run any (!) cooler. It just doesn't work that way and those that think it does are simply incorrect. A cooler thermostat will cause the engine to run cooler in very cold ambient conditions when it's of no benefit to do but not in hot conditions. And before you disagree, think about what the 165, 180, and 195 degree thermostats have all already done by the time the engine reaches its 210 temperature. ALL have already opened fully, none can flow any more water or cause the engine to cool any more efficiently in hot conditions.

Really Jerry? are you telling me that my engine cannot and does not run cooler with my 180? No what you are saying is that YOURS did not. Every time this topic comes up you chime in with your song and dance that it will not run any cooler. Well you are wrong! Mine does and so do other peoples. If you have a thermostat that will not open prior to 195 that is the coolest that engine will run, regardless of all other things involved. As the engine begins to run cooler, the thermostat will close slightly to keep it at that preset temp. If you have the cooling capacity to run cooler than that, and the thermostat is rated to open at a lower temp,it can and will run cooler. If your cooling system cannot keep up with the heat for whatever reason, then yes you could put in a 160 or 180 or whatever temp you want, it will open at that temp and not run any different than before because it cannot cool any more than whatever that temp is. When I got my Jeep it had a 160 in it because it would not even make it up to the first line on the temp gauge. Too cold at that point esp in the winter. I have experimented with several differnet stats in mine and the 180 keeps it right where I want it, just to the left of the 2 which I think is right around 190, no mils, opassed smog with no issues, 15-16 mpg. Now being as how I live in the high desert 15 miles from Johnson Valley, I know a little about the desert conditions that you wheel in, and have for the past 10 summers, the last 2 in this Jeep.

Jerry Bransford 07-30-2010 12:21 PM

My "song and dance"? We've "danced" other issues before that you also strongly believed in so you are of course free to believe whatever you want to. Re-read what I said though, I NEVER said an engine cannot run cooler with a lower temperature thermostat. I already said it will run cooler in colder ambient weather conditions. What I DID say is that the engine won't run any cooler with a 180 degree thermostat when running in hot ambient weather conditions. You say you've driven in the high desert for ten years and two years in your Jeep, I've been driving in the desert for forty plus years and fourteen years in my Jeeps.

I thought I knew better years ago and installed a 180 degree thermostat and finally figured out what I said above... it causes the engine to run cooler in cold conditions but it cannot force the engine to run cooler in hot conditions. That is not what thermostats do, they do not have magical properties that can force an engine to run cooler in hot conditions. If they could, we would never have to worry about overheated engines again.

But again, believe whatever you want.

DevilDogDoc 07-30-2010 12:33 PM

So am I misreading my temp gauge? And I am not arguing cold weather operation here I am talking about yesterday when it was 110 degrees in Palm Springs, in my Jeep. You are correct about the oil issue, I was misquoting the FSM in that I was wrong. Its not magic it is a purposeful bottleneck placed in the cooling system. I have removed that bottleneck is all. My cooling system is in outstanding conditions and thats why it can and does run cooler. If anything were subpar, it would not be this way because the cooling system couldnt keep up, maybe in your case with your winch in the way it wouldnt make a difference. What gets me is that just because YOU couldnt get the results I have, no one can. Am I lying? Should I post video of my gauge in front of a big thermometer? Tell you what you don't want to believe me fine. The next time you are heading up to JV, swing by my house for a cup of coffee and I will show you, I am right off of 247, I extended the same invite when I was at Blaines house last month,come on by!!

rrich 07-30-2010 01:09 PM

Seems like the whole idea behind a thermostat has become lost here.

The T Stat determines the lowest temp - by closing when the coolant is cooler than it's set for. It has nothing to do with whether it runs cooler above the setting.
It's the lower stop point.

The hotter coolant temp allows the engine to run a little more efficient - not even regarding the computer. Even without a computer, efficiency goes up and emissions down. That's why when doing a smog test it has to be warmed up fully - if it fails, the smog machine has the operator run a "3 minute pre-conditioning" run to make sure it is fully warmed up.

The computer is looking for the higher coolant temp through the coolant sensor. If if runs too cold it stays out of closed loop and richens the mixture - like having a choke on. If the ECM detects that it's way way too hot, it will retard the timing and richen the mix a little.

If you want your computer to act like it's keeping a choke on, put in a lower temp T Stat.

Devil - I don't know why you have to argue a basic point. But do what you want.

DevilDogDoc 07-30-2010 01:27 PM

Thats my point rich, regardless of all the other effects on the ECU and such is the point that a cooling system in proper operating conidition can and will run cooler than 210 with a lower stat, because the stat stops it from running any cooler than what it is set to open at. My 180 will not allow the temp to fall under 180 a 195 at 195 etc. I understand the concept and I am sure a master tech like yourself does also. I just hate being told that something that I see everyday for 2 years is a lie because someone else is unable to reproduce it. Iam done arguing at this point and whether anyone else belives me is irrelvant, I know what my gauge shows pulling the grade coming up from DHS or up 247 towards your palce.

rrich 07-30-2010 02:13 PM

Do you go to the HD4 meetings in Yucca?

DevilDogDoc 07-30-2010 03:10 PM

Haven't tet but was planning on going to the next one that would be next Thursday wouldn't it?

mcoh1030 07-31-2010 06:01 AM

Mama Mia!!
 
At Ease!!

The enemies out there, not in here. K?

What I need to know, is if I had put in a 180 t-stat and the "check engine" light momentarily came on and then I replaced that 180 stat with the proper 195 stat, is it possible that my Jeep's computer made an adjustment to, fuel, timing, whatever that would cause it to run hotter than 210??

I've never seen the gauge go above 210 and now it consistantly is running at 215 to 225.

I'm in Florida and it's hot, say 90 degree every day. But what I'm affriad of is driving it hot and blowing a head gasket. Please help.

Jerry Bransford 07-31-2010 07:36 AM

Quote:

Originally Posted by mcoh1030 (Post 707409)
What I need to know, is if I had put in a 180 t-stat and the "check engine" light momentarily came on and then I replaced that 180 stat with the proper 195 stat, is it possible that my Jeep's computer made an adjustment to, fuel, timing, whatever that would cause it to run hotter than 210??

No, not at all. It is possible however that you might have introduced some air into the cooling system when you swapped thermostats that now needs to be "burped" out. An air bubble near the temperature gauge sender can cause it to indicate the engine is running hotter than it really is.

mcoh1030 08-01-2010 06:06 AM

Jerry,

Thank you for your direct response. Can you tell me what I can do to remove the bubble of air near the temp sending unit? What symptoms would there be??

It's funny because about a week ago, it was running hotter than it is today. A week ago, it was running a 225 now 215. So what gives????

I'm also of the firm belief that lowering the thermostat degree will merely permit coolant to be released into the radiator sooner/at a lower temp. The effect that that has is it allows the engine to begin cooling sooner. But, will not change the dimensions, capacity, coolant type or flow. Therefore, if the system is designed to run at approx. 200, changing the thermostat to a lower degree, will only cause the system to begin cooling sooner. It will not permit the system to cool more effectively.

Removing the thermostat can have the effect of allowing the engine to run cooler. The reason is because the thermostat when fully opened, (and they are usually the same, 160, 180, 195) only opens approx 1/4 inch around the entire circumference of the t-stat. Thereby allowing only a certain amount of coolant to pass into the t-stat housing and back into the radiator to be cooled.

Removing it all together permits greater capacity of coolant to leave the engine hot and be supplied to the radiator for cooling. This could have the effect of allowing more coolant into the radiator effectively cooling more surface area of coolant, thereby dropping the coolant temperature.

Techincally, the amount the t-stat opens is direct relationship to the water pumps volume capacity and it opens just enough to provide for the coolant that is in the radiator to move through it at a rate which allows the coolant to drop in temperature. It drops niether too much nor too little.

Of course this is all effected by the # of fan blades, the rate at which the fan pulls air through the radiator, the ambient outside temperature, the mixture ratio and type of coolant and the volume at which the water pump moves the coolant. There are other factors, such as size and type of radiator, types of hoses ect...

Now if I could just figure out why my Jeeps running hot. Again, if it's an air bubble, what sings would there be. Would the gauge fluxuate around turns? It's doing that slightly. Another things I've noticed is that it runs at 215-220 with the rad cap on, but with it off it holds a steady 190. Any thoughs there???

jeepjones 08-01-2010 11:05 AM

Quote:

Originally Posted by DevilDogDoc (Post 706619)
Really Jerry? are you telling me that my engine cannot and does not run cooler with my 180? No what you are saying is that YOURS did not. Every time this topic comes up you chime in with your song and dance that it will not run any cooler. Well you are wrong! Mine does and so do other peoples. If you have a thermostat that will not open prior to 195 that is the coolest that engine will run, regardless of all other things involved. As the engine begins to run cooler, the thermostat will close slightly to keep it at that preset temp. If you have the cooling capacity to run cooler than that, and the thermostat is rated to open at a lower temp,it can and will run cooler. If your cooling system cannot keep up with the heat for whatever reason, then yes you could put in a 160 or 180 or whatever temp you want, it will open at that temp and not run any different than before because it cannot cool any more than whatever that temp is. When I got my Jeep it had a 160 in it because it would not even make it up to the first line on the temp gauge. Too cold at that point esp in the winter. I have experimented with several differnet stats in mine and the 180 keeps it right where I want it, just to the left of the 2 which I think is right around 190, no mils, opassed smog with no issues, 15-16 mpg. Now being as how I live in the high desert 15 miles from Johnson Valley, I know a little about the desert conditions that you wheel in, and have for the past 10 summers, the last 2 in this Jeep.

:rofl::rofl::rofl::bottom:

DevilDogDoc 08-01-2010 11:13 AM

^^^^ lmao!!!!!!

mcoh1030 08-01-2010 02:04 PM

Getting back to where I need help. Is it possible for the 195 thermostat to be opening at the wrong temp.?

It seems as though it might have been damaged when I first overheated. If that is the case, would the vehicle run hotter if the thermostat was only opening at 210 or 215?

Neil F. 08-01-2010 02:57 PM

Quote:

Originally Posted by mcoh1030 (Post 708457)
If that is the case, would the vehicle run hotter if the thermostat was only opening at 210 or 215?

No. Once it is open, it is open. When it is open, the temperature the system runs at is dependant on the cooling system ability to exchange the heat with the ambient air. It would not matter if it was a 160, 180, 195, 210.

lancetkenyon 08-01-2010 08:04 PM

With all the banter that is going on here, run your rig with the recommended t-stat. Your Jeep will not overheat at 210, or 195, or 180. A 180* t-stat does not do any good, or any harm either. I have run a 195* t-stat since my rig was new(9 years), with 3 different radiators(2 cracked from wheeling "incidences"). I can run my A/C on the trail or on the roads, at idle for hours on end, or high RPMs with sustained driving. I live in AZ, so I know what hot is. It has been 116* here the past couple weeks at times, and night wheeling is still 105*+.

30-284 08-01-2010 09:20 PM

Quote:

Originally Posted by mcoh1030 (Post 708457)
Getting back to where I need help. Is it possible for the 195 thermostat to be opening at the wrong temp.?

Anything is possible but, some thermostats are more restrictive than others so if different brands are available to you then check for the least restrictive. I believe hi flow thermostats are available.

Donn

mcoh1030 08-02-2010 06:13 AM

Neil,

If the stat is opening at 212, then the coolant must reach that point before the stat opens to allow the coolant to pass into the radiator. Which suggests that if it's malfunctioning, the coolant would remain at the temp. to which it is opening. Or at least thats my theory.

Kilroy 08-02-2010 09:22 AM

We have not quite beat this to death. Don't forget the thermostat's throttling range....

Neil F. 08-02-2010 10:16 AM

Where are you getting the idea that the thermostat in malfunctioning to start with. 225 is not "overheating" 240+ is the range that it is getting too hot. The ambient conditions and the condition of you cooling system have a lot to do with the temperatue your system runs at. There is noting that will be "damaged" in a thermostat by overheating (which 225 is not) and magically it's setpoint will be changed.

lmurry 06-25-2013 03:58 PM

when i had my 06 wrangler the temp gauge was always in the middle, whether it was summer or winter. when i put in a 180 degree thermostat the needle on the temp gauge was a little less then a 1/4 of an inch to the left. and it stayed there in summer and winter. so is my engine running cooler or not? is it true a cooler running engine lasts longer or is that a myth? no engine lite ever came on with the lower temp thermostat. bought a '13 wrangler a few months ago, cause they finally have some decent horsepower, and want to put a 180 degree thermostat in it also, if i can ever find one. i live katy texas and i does get pretty hot here in the summertime. appreciate any comments on this:)

Jerry Bransford 06-25-2013 04:03 PM

Your engine & computer were designed around using the correct factory specified 195 degree model thermostat. The only time your engine will run cooler with a lower-temp thermostat is on cold or cool days. On a hot day, the thermostat temp is irrelevant since it is wide open no matter what temperature model thermostat it is.

flflash 06-25-2013 04:19 PM

Quote:

Originally Posted by mcoh1030 (Post 706390)
from a 195 to a 180 cause the computer chip to adjust?

No

So that when the vehicle is running, it runs hotter than normal?

No

I've been told that putting in a 180 thermostat can effect the rate at which gas is sent into the cylinders by the computer Wrong. In my 2000 I took out the 195, breifly put in a 180, (which momentarily cuased the "check engine" light to go on when it first hit operating temp.) and then reinstalled my 195 as the 180 was a FAIL-Safe that failed almost immediately.

You may have set a dtc po249 failure to reach operating temp in specified time limit if the 180 thermostat had already failed open and allowed coolant to flow to early.
Your better off leaving the factory 195 degree thermostat in and making sure that all parts of the cooling system are properly operating. Swapping in a 180 will not make a system run cooler the heat load and cooling capability's of the system are what determines the temperature the vehicle runs at. Thermostats are just there to get the engine up to an operable temperature sooner to improve engine efficiency, engine life and get the heater operating quicker.

UnlimitedRubicon 06-25-2013 04:19 PM

Quote:

Originally Posted by lmurry (Post 3898596)
when i had my 06 wrangler the temp gauge was always in the middle, whether it was summer or winter.


The vehicle was working correctly.


Quote:

Originally Posted by lmurry (Post 3898596)
bought a '13 wrangler a few months ago


Did you buy it new and is it under warranty?


Quote:

Originally Posted by lmurry (Post 3898596)
want to put a 180 degree thermostat in it also, if i can ever find one.


Don't bother. It's not going to do anything beneficial.


Quote:

Originally Posted by lmurry (Post 3898596)
i live katy texas and i does get pretty hot here in the summertime.


I live and wheel in Southern California where the temp regularly hits 100+ during the late summer/early fall. If your engine and cooling system are properly functioning and maintained the temps won't affect your Wrangler.

JimsJeep 06-25-2013 04:27 PM

Quote:

Originally Posted by Jerry Bransford (Post 706588)
Why do some people think it is wise to install a 165 or 180 degree thermostat that opens sooner than the Jeep engineers designed the engine and programmed computer for? :confused:

I have done a LOT (!!!) of modifications to both of my TJs, wheel in the hottest desert conditions, and I still choose to run the factory recommended 195 degree thermostat. I really don't see the sense of installing a 165 or 180 degree thermostat when the factory specified 195 degree thermostat works fine.

In hot desert conditions, running a 165 or 180 degree thermostat will NOT (!!!!!!!!!!) cause the engine to run any (!) cooler. It just doesn't work that way and those that think it does are simply incorrect. A cooler thermostat will cause the engine to run cooler in very cold ambient conditions when it's of no benefit to do but not in hot conditions. And before you disagree, think about what the 165, 180, and 195 degree thermostats have all already done by the time the engine reaches its 210 temperature. ALL have already opened fully, none can flow any more water or cause the engine to cool any more efficiently in hot conditions.

I had an argument with a mechanical engineer in the old World Trade Center regarding the reason they specified pipe insulation on all sprinkler systems within 10' of the window wall. He said is was to keep the water from freezing. (water is static in pipe) I told him ambient temperature is ambient temperature and that insulation will not warm the pipe. So what possible good could that do. I lost by virtue of seniority.

Based on that same note, put 3 similar jeeps side by side in the desert, 1 with a OEM stat one with a 165 and one with no stat. Let them idle at the same RPM for one hour. Will the jeeps record different operating temperatures, not possible.

Jerry Bransford 06-25-2013 04:44 PM

Nicely put, X2, and I bet that was a frustrating conversation on that pipe insulation. Some people are smart yet stupid at the same time. :p


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