Low temp Thermostats and engine wear

[PowerWagon896]

There have been concerns expressed lately, both here and on other sites, regarding increased engine wear associated with changing to a lower temperature thermostat than OEM specifications.

I copied this information off of Underdog Racing Developement's website. Even though it addresses the 3.4 V6 engine, I think the same theory should apply to any engine.


A LINK TO THE WEB PAGE FOLLOWS TEXT




What Thermostat do I use with my 3.4 L V6? Can I buy one from URD?
UNDERDOG RACING DEVELOPMENT recommends that you use a Stant 170 degree thermostat or a stock 180 degree thermostat in your 3.4 L 5VZ-FE. The Stant part is #14007.
Although we supply a 170 degree thermostat with our Fuel Kits, we are not selling the thermostat by itself. They are readily available from NAPA and Advanced Auto Parts. We don’t want to overcharge you for an item that is easily picked up by you for less.
When engine coolant temperature is lowered in the supercharged 3.4 liter 5VZ, power marginally improves. You likely won’t feel much power gain in the seat of your pants.
There is some misinformation out there as to why a cooler thermostat increases engine performance. Some people think a cooler thermostat makes the engine run richer. It does not. It heats the air entering the engine less creating a denser fuel/air charge thereby developing more power. Cooler induction air is less prone to induce spark knock so the ECU can run more aggressive ignition timing resulting in greater power.
UNDERDOG RACING DEVELOPMENT experimented with two lower temperature thermostats available for the 3.4 V6 engine; the pricey TRD 160 degree thermostat, and the Stant 170 degree thermostat.
We have three minor concerns about the 160 degree thermostat. They are: Engine wear (very minor concern), fuel economy, and cold weather driving. Hot engine coolant enables the heater to keep occupants warm. How much power gain is worth freezing your bottom? NONE should be the correct answer for most of us. We have tested both units. The 170 degree thermostat keeps us nice and toasty. The 160 degree thermostat never gets hot enough in very cold weather.
Modern gasoline requires higher engine temperatures to burn efficiently and provides the best fuel economy. The correct water temperature is required for cylinders to achieve a minimum specific temperature in order to allow a fully homogenized air/fuel mixture to combust efficiently. The 170 degree thermostat reduces actual coolant temps from just over 190 degrees on our test vehicle to 180 degrees. Lowering coolant temperature in the engine any further may cause poorer fuel economy and reduced engine life through additional wear. There are better ways to make extra horsepower in our opinion.
In summary, UNDERDOG RACING DEVELOPMENT believes the Stant 170 degree thermostat increases engine performance, and at the same time it does not negatively impact fuel economy or potential accelerated engine wear. It is a cheap upgrade. Heater performance is also minimally affected. This is the thermostat we have decided to run in our own trucks. You can find it for around $13 at your local auto parts store.

CLICK THIS LINK FOR THE URD WEBSITE
http://www.urdusa.com/information.php?info_id=4

[joseph]

They basically say it's ok to go from stock 180 to 170, but not 160 for the V6, it's like our hemis, using the 180 is ok, but using the 160 is only for racing and not for daily driving, so it's ok to use the lower temp thermostat, as long as it's not too much cooler than stock it's fine.

[stevesrt8]

basically good info. Years ago, Ford did the research and found that engine wear (specifically piston/cyl.wall) went up as temp went down. This was quoted in HP books about rebuilding engines.

So, if it's worth a very minor increase to you, give it a shot. Meister did a lot of R&D on this subject and published great info more relative to hemis.

You can bet the computer will notice and dial in an adapt sooner or later. The only question is will you like the result.

[PowerWagon896]

:bump:

[bmartin9122]

My only complaint with my 170 tstat is the dash warning lamp being almost continuously illuminated because the engine never reaches 180 normally and consistently.

[PowerWagon896]

[quote=bmartin9122;689074]My only complaint with my 170 tstat is the dash warning lamp being almost continuously illuminated

I personaly have had 1 CEL W/the 383-170 Robertshaw. It was during slick road conditions, right around freezing & I was driving very consrvatively in "D". This is after over 16,000 miles of driving. Wifey has gotten perhps 6 CELs, always in "D". I drove 13 miles to work tonight in -6F to -10F temperatures W/O a CEL. After the coolant temperature stated to show on the gauge, I ran the heater in "recicutate cabin air mode" & stayed in autostick & kept the revs around 2000 RPM until the temperature gauge reached the 11 o'clock "hashmark".

Driving in autostick until the TSTAT opens @ 176* has eliminated CELs for me. Autostick eliminates MDS mode and allows the engine to warm up faster, especially when you keep the revs up by running in the lower gears & applying as much throttle as traffic/road conditions allow.

If I could find a similar "failsafe" design TSTAT in 180* I would install one.

[bmartin9122]

I would do the same thing. I think a 180 Robert-Shaw would be a perfect balance for non-racers like me.

[PowerWagon896]

I would do the same thing. I think a 180 Robert-Shaw would be a perfect balance for non-racers like me.

Is your's the 383-170 Robert Shaw?

If you have EVIC see where the TSTAT is opening/closing. It should be 176*/172* respectively.

Your's may be defective.

[bmartin9122]

Is your's the 383-170 Robert Shaw?

If you have EVIC see where the TSTAT is opening/closing. It should be 176*/172* respectively.

Your's may be defective.

That is about right. My understanding is the CEL is triggered if you do not meet or exceed 180. I remember the 176 - not the other. You can see exactly what I have in my KB post (http://www.lxforums.com/board/showthread.php?t=39710).

[formerice]

I run 180's in both of my hemis. I doubt if a 170 will give you much more power at the track. Before with the stock tstats it felt like a blast furnace under the hood. Heaters work fine in below zero conditions, no discernable difference in mileage with the 180's over stock. The truck stays at 180 at the track or heavy traffic, the magnum will heat up till the fan comes on.

[PowerWagon896]

I run 180's in both of my hemis. I doubt if a 170 will give you much more power at the track. Before with the stock tstats it felt like a blast furnace under the hood. Heaters work fine in below zero conditions, no discernable difference in mileage with the 180's over stock. The truck stays at 180 at the track or heavy traffic, the magnum will heat up till the fan comes on.

It's not the few degrees difference that makes me prefer the 383-170 over the various 180s out there, but the "failsafe" design. The 383-180 Robertshaw "fails open" not closed. No possibility of overheating due to a failed TSTAT.

[MadCharger]

I've been getting thermostat codes with my 170 tstat ever since the weather cooled. These codes were only showing up with the SuperChip DTC checks, not as a CEL. However, lately I've been getting it as a CEL. If you're running the 170, and not getting a CEL, check your DTC's with the SC and see if there are still codes being thrown....

[Wetcoast]

A really, really good analysis on post # 3

http://www.dodgeforum.com/m_460053/tm.htm (http://www.dodgeforum.com/m_460053/tm.htm)

[GoldNnasty]

As was stated on another forum, cooler thermostat = cooler trans temp.
A Bonus !

[SKALLAN]

:sad: Running the Robert Shaw 176 Stat. Got CEL yesterday, how do you clear?

[OITZBAD]

I got the Robbert Shaw 180' termostat, and its great and even better now that i got the GS esp/fan mod, now I don't worry about unwanted heat.

[Redfox0099]

I run a 160 * thermo in my SRT for over 18K miles now...wonder why I never get a code for TSTAT?

[PowerWagon896]

I run a 160 * thermo in my SRT for over 18K miles now...wonder why I never get a code for TSTAT?

A lot of it has to do W/ambient temperatures & driving habits Redd.

The only time I ever got a CEL W/the 160 or 170 TSTAT was during cool damp conditions where I was driving very conservatively.

Wifey however, gets them quite regularly even W/the 185 Robertsahaw.

I have since re- instaled the OEM TSTAT for everyday driving & I will only replace it W/the Robert shaw 170 (it runs @ 174-176*) when the temperatures get a little warmer in a month or so.

I do think that the 160 is a tad low for everyday driving & could accelerate cylinder wall wear somewhat. A coolant temperature of about 180* seems to be the best compromise for power & engine life.

I do switch to the Milodon 160 for track use as it keeps things cool in the staging lanes.

[OITZBAD]

I've got the Rober Shaw 383-180, and have had no codes. And I've also got GS Motorsports esp/fan mod and I always leave my fans on, and my temps run from 176-180s and maybe touch 190s if I'm hard on it.

[Dan79]

It's not the few degrees difference that makes me prefer the 383-170 over the various 180s out there, but the "failsafe" design. The 383-180 Robertshaw "fails open" not closed. No possibility of overheating due to a failed TSTAT.

I know this is an old post by you, but nowadays we have the 4128 180 tstat and that one is failsafe and good for most of us daily drivers, correct?

[Hal'sMag]

That's correct.
I've run both the 4127 and 4128.
The 4128 runs about 10 degrees higher at 188-192 on the road or with fans.
I personnally have seen little improvement for daily driving going to the 4127,

[bmartin9122]

I run a 160 * thermo in my SRT for over 18K miles now...wonder why I never get a code for TSTAT?

You have an Aggie computer......











Phew... I hadn't done that in a long while, and it fealt GOOD!

[JMatt]

What I don't understand, is why are people always so concerned with the check engine light anyway?

Turn the key on - get the code: P0128. Big deal. Your light is telling you that your engine isn't getting up to the temp it expects to get up to.......because you put in a lower temp thermostat. Duh. I just check my code, and know that I caused the CEL on purpose. I also have a scantool plugged into my obdii port non-stop. Whenever I feel like it, I just reset the light. No biggie.

(MY CEL is also always lit with codes P0420 and P0430. Apparently, my catalytic converters don't work very well from the floor in the corner of my garage) :mrgreen:

[bmartin9122]

What I don't understand, is why are people always so concerned with the check engine light anyway?

Turn the key on - get the code: P0128. Big deal. Your light is telling you that your engine isn't getting up to the temp it expects to get up to.......because you put in a lower temp thermostat. Duh. I just check my code, and know that I caused the CEL on purpose. I also have a scantool plugged into my obdii port non-stop. Whenever I feel like it, I just reset the light. No biggie.

(MY CEL is also always lit with codes P0420 and P0430. Apparently, my catalytic converters don't work very well from the floor in the corner of my garage) :mrgreen:

My concern is I have a 6-year bumper-to-bumper warranty. When I take it to the dealer for service, they are likely to "fix" my thermostat when they see the CEL.

[JMatt]

My concern is I have a 6-year bumper-to-bumper warranty. When I take it to the dealer for service, they are likely to "fix" my thermostat when they see the CEL.
OK - that's a valid point.

Depending on your service department, you could just tell them what you've done - but that may cause a bigger problem. Or you could just reset the light. OR - make sure to get the engine hot 3 times in a row, and the light goes back out.

[bmartin9122]

OK - that's a valid point.

Depending on your service department, you could just tell them what you've done - but that may cause a bigger problem. Or you could just reset the light. OR - make sure to get the engine hot 3 times in a row, and the light goes back out.

Or you can put in a 180 tstat and get no CELs which require attention. It all depends on what is important to you. I just want to get in my ride and drive. If my friends get in, then I don't want to have to explain that my car isn't a piece of junk.

[QuickRT2SRT]

I always restore my stock program before I take it back to the dealer anyway and that clears any codes and resets the 3 keycycle count.
Never been a problem. I run the 4127 in hot weather, and the 4128 in colder weather. works fine for me. Running coolant temps above 189-190 will cost ya a degree of timing that HAL takes away to protect the motor for ya.