Best Thermostat brand for Hemi

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nwjones18

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I know this has been discussed, but couldn't really find anything current other than this thread where @Chris142 got a reboxed Motorad for his Jeep:

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Thread 'Faulty Motorad Thermostat 281180'

I put in a MOTORAD 281180 in my 00 Toyota Celica GTS 6mt last year, and now after 1 yr and 3k miles, it's doing the same thing as mentioned from this earlier thread 13 years ago by another user. Now it's colder, I went on a 26 mile all highway drive and it never got past 3/4 on the way to full op temp. It only reached it at the end, when I was in a bit of traffic on the exit ramp. Should have just bought the Aisin JP made one from the jump, was only $15 difference (but then would have had to wait a few days rather than going to the store)

Just putting this out there if someone does a...
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My 2016 Ram is due for a coolant flush and it seems prudent to replace the thermostat. Personally I've had awful luck with Motorad's in the past and would like to avoid if possible, so here are the choices on Rock Auto:

AISIN THRCH0001 $10.73
CALORSTAT TH721795J $11.84
GATES 34053 $16.86
MOPAR 52028898AJ $62.79
MOTORAD 5416203 UltraStat $15.73



I don't mind spending the money on Mopar, unless I'm going to get a $16 Motorad in a $64 Mopar box.. I'm intrigued by the Aisin and Calorstat options. Which would you choose?

I'm a little tempted to order the Aisin, Calorstat and the Motorad ultra, compare them and install the one I think looks the best... Would cost less than the Mopar..
 
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Owning 3 5.7l hemi, I have learned that the OEM one is really the one to use. For some reason the Motorad/Stant thermostats seem to have some weird issue were the rubber on the diaphragm wells or pushes out and doesn't allow the stat to close all of the way. Among your other options, I would feel best with the Aisin. I've used them in other vehicles and them seem to be good.
 
I, too, would not replace a working thermostat. And if I was, I would get an authentic OEM one as Timmastertech explains in the linked thread above. It's very sad about the aftermarket parts hit or miss situation.

However, if you have the time and patience to experiment, have at it.
 
A thermostat is about the only part on any of my cars where I will drive directly to the nearest dealer, walk into the parts department, and hand over whatever outrageous sum for an OEM part, versus taking a chance on Autozone or Rockauto or anywhere else. I've had way too many aftermarket thermostat failures to ever trust one ever again, going back 20+ years.
 
The difference here is this isnt an old jeep. The OE thermostat should still be available and not a motorrad.

And its definitely worth it.
 
I'm at that point as well with my 5.7 and I plan to bite the bullet and get the Mopar.



Does anyone change hoses anymore? Are Gates still the go to for rubber?
 
nwjones18 said:
I know this has been discussed, but couldn't really find anything current other than this thread where @Chris142 got a reboxed Motorad for his Jeep:

C

Thread 'Faulty Motorad Thermostat 281180'

I put in a MOTORAD 281180 in my 00 Toyota Celica GTS 6mt last year, and now after 1 yr and 3k miles, it's doing the same thing as mentioned from this earlier thread 13 years ago by another user. Now it's colder, I went on a 26 mile all highway drive and it never got past 3/4 on the way to full op temp. It only reached it at the end, when I was in a bit of traffic on the exit ramp. Should have just bought the Aisin JP made one from the jump, was only $15 difference (but then would have had to wait a few days rather than going to the store)

Just putting this out there if someone does a...
  • Sad
  • Like

My 2016 Ram is due for a coolant flush and it seems prudent to replace the thermostat. Personally I've had awful luck with Motorad's in the past and would like to avoid if possible, so here are the choices on Rock Auto:

AISIN THRCH0001 $10.73
CALORSTAT TH721795J $11.84
GATES 34053 $16.86
MOPAR 52028898AJ $62.79
MOTORAD 5416203 UltraStat $15.73



I don't mind spending the money on Mopar, unless I'm going to get a $16 Motorad in a $64 Mopar box.. I'm intrigued by the Aisin and Calorstat options. Which would you choose?

I'm a little tempted to order the Aisin, Calorstat and the Motorad ultra, compare them and install the one I think looks the best... Would cost less than the Mopar..
Click to expand...
I've been looking for a replacement thermostat after the motorad has become lazy after only a year. Rockauto supposedly has actual stant superstant thermostats on closeout. The oem usually have much tighter requirements.
 
My vote is MOPAR, you don't want to have to change it again prematurely even if free. Too much PITA.
 
I installed the Aisin today. Physically it seemed to be just as good as the OEM. We'll see how it does. I replaced the belt as part of my 10yr maintenance and discovered the Waterpump has play in the bearing... Ordered an Aisin one of those as well. Naturally I discovered that after I did a coolant flush... Oh well.
 
nwjones18 said:
I installed the Aisin today. Physically it seemed to be just as good as the OEM. We'll see how it does. I replaced the belt as part of my 10yr maintenance and discovered the Waterpump has play in the bearing... Ordered an Aisin one of those as well. Naturally I discovered that after I did a coolant flush... Oh well.
Click to expand...
A big, clean tub and paint strainers will save the fluid.
 
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nwjones18 said:
I know this has been discussed, but couldn't really find anything current other than this thread where @Chris142 got a reboxed Motorad for his Jeep:

C

Thread 'Faulty Motorad Thermostat 281180'

I put in a MOTORAD 281180 in my 00 Toyota Celica GTS 6mt last year, and now after 1 yr and 3k miles, it's doing the same thing as mentioned from this earlier thread 13 years ago by another user. Now it's colder, I went on a 26 mile all highway drive and it never got past 3/4 on the way to full op temp. It only reached it at the end, when I was in a bit of traffic on the exit ramp. Should have just bought the Aisin JP made one from the jump, was only $15 difference (but then would have had to wait a few days rather than going to the store)

Just putting this out there if someone does a...
  • Sad
  • Like

My 2016 Ram is due for a coolant flush and it seems prudent to replace the thermostat. Personally I've had awful luck with Motorad's in the past and would like to avoid if possible, so here are the choices on Rock Auto:

AISIN THRCH0001 $10.73
CALORSTAT TH721795J $11.84
GATES 34053 $16.86
MOPAR 52028898AJ $62.79
MOTORAD 5416203 UltraStat $15.73



I don't mind spending the money on Mopar, unless I'm going to get a $16 Motorad in a $64 Mopar box.. I'm intrigued by the Aisin and Calorstat options. Which would you choose?

I'm a little tempted to order the Aisin, Calorstat and the Motorad ultra, compare them and install the one I think looks the best... Would cost less than the Mopar..
Click to expand...
I have a motorad ultrastat that was supposedly a Stant but it loses temperature quickly when I quickly accelerate down the highway. It recovers very slowly. It's a bummer Stant went under as they made a great product. I'd go oem once and done.
 
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Back in the day Stant was a trusted aftermarket name for thermostats. Not anymore and Motorad is the worst of all and they show up in many name brand boxes including duralast and came in a GM part box ( Cadillac CTS 3.6L application) once too!!

I just flushed the coolant on my 2016 Ram Limited Hemi 5.7 - but left he original OEM thermostat alone. I want to change it because I am at 156k miles but it shows no signs of failure so I'll wait a bit longer and replace it at the next coolant service or if it fails before that with a new Mopar unit.
 
The thermostat is the one item I always insist on OEM.

When the OEM thermostat fails, it fails in the open position. The opposite can be detrimental.
 
I don't replace many thermostats, but I had a case nearly 30 years ago where my OEM thermostat stuck open in my 96 GMC 1500. Based on my experiences in the 80's I put in a brass Stant. It seemed to work OK for a short time, then failed open. I put and OEM back in it and restored normal Ops for the remaining 10 years I had the truck. Access on that truck wasn't bad, some of the newer vehicles look to be worse.
 
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