Motorad Ultrastat

[Lockasiam]

Think the 3.8L grand caravan has a failed thermostat.

(This is how i came to the conclusion, ignore this if you want) I've always monitored the coolant temp on my scangauge, but now it's being weird. typically from cold it'll creep up to about 89-90*C and sit there for the entire drive. Had a massive coolant leak over winter and now that that's fixed it'll creep up to 98*C and then drop back to high 80's and continue its climb until it sits at 91*C. When driving fast or under load it'll fluctuate between the 91 and 98 mark with no real settle point.

The question I'm wanting to ask is, has anyone had any experience with Motorad UltraStat? It's listed as the "heavy duty" option on rockauto and has the best flow rate and lifespan out of the Motorad options for a solid $3 more than the "standard replacement" that i've heard slander about

 

[97prizm]

I had one bad from Advance auto. I'm bummed that Stant sold out to motorad. The second one was perfectly fine three years later. You definitely want the heavy duty thermometer as they have a varible spring for more consistent temperatures and are better built. The cheap motorads feel and are flimsy and cheap.

 

[Chris142]

Sounds like it already has a Motorad thermostat in it.

 

[slacktide_bitog]

From what Rock Auto has, get Calorstat or Vemo. They'll be your best chance of getting a thermostat that isn't Motorad

 

[thastinger]

I bought one of their "Fail-safe" ones that was supposed to be a 192 but temps never got over 180 (monitored via SCT livewire). I replaced it with another brand 190 and now my temps are 190-192.

 

[zzyzzx]

90 degrees C = 194 degrees F.
Sounds like your existing thermostat is working fine.

 

[Lockasiam]

90 degrees C = 194 degrees F.
Sounds like your existing thermostat is working fine.

It's not opening until it's near boiling which is not normal

 

[zzyzzx]

Is there a non-Motorad thermostat available for this vehicle?

Obligatory:

 

[Lockasiam]

Is there a non-Motorad thermostat available for this vehicle?

https://www.rockauto.com/en/catalog....8l+v6,1431387,cooling+system,thermostat,2200

 

[zzyzzx]

https://www.rockauto.com/en/catalog....8l+v6,1431387,cooling+system,thermostat,2200

So that's a yes, as in the Calorstat and VEMO. (I think). The rest I think are Motorad.

 

[Lockasiam]

So that's a yes, as in the Calorstat and VEMO. (I think). The rest I think are Motorad.

correct, and a $22 mopar

 

[slacktide_bitog]

correct, and a $22 mopar

which might also be an aftermarket Motorad

ask @Chris142 about that

 

[Chris142]

correct, and a $22 mopar

Gotta watch that. I bought one from the dealer or my jeep and inside the jeep bag was a Motorad.

 

[nwjones18]

Is there a non-Motorad thermostat available for this vehicle?

Obligatory:
View attachment 266279

It never gets old.. haha

If all I can find is Motorad I'll wait for an OEM stat to come in..

 

[D60]

It never gets old.. haha

If all I can find is Motorad I'll wait for an OEM stat to come in..

Order a Calorstat from RA and tack some other needed things on the order. Gear oil, ATF, maybe an errant window switch or electrical connector ‐‐ whatever comes from the same warehouse.

I did "have to" drill a tiny bleeder hole in the Calorstat I installed, but an 1/8" bit and scrap wood backer makes that a 15 second affair....

 

[Marcozi]

If you plan n keeping the ride for a few years or more I recommend you buy a new thermostat from the dealer.

 

[D60]

If you plan n keeping the ride for a few years or more I recommend you buy a new thermostat from the dealer.

Again, there's credible reason to believe the Mopar boxes -- at least for older vehicles -- contain Motorad.

Chrysler/FCA/Stellantis/Cialis whatever have no interest in maintaining quality parts supply for older vehicles like anything with the minivan 3.8. [Valley girl voice] That was like soooo yesterday [/Valley girl voice]

That said, no harm except for potentially wasted time and a restocking fee in ordering an OEM 'stat and seein' what ya receive.....

 

[Lockasiam]

Again, there's credible reason to believe the Mopar boxes -- at least for older vehicles -- contain Motorad.

Chrysler/FCA/Stellantis/Cialis whatever have no interest in maintaining quality parts supply for older vehicles like anything with the minivan 3.8. [Valley girl voice] That was like soooo yesterday [/Valley girl voice]

That said, no harm except for potentially wasted time and a restocking fee in ordering an OEM 'stat and seein' what ya receive.....

Death to Stellantis

 

[zzyzzx]

If all I can find is Motorad I'll wait for an OEM stat to come in..

The OEM one might also be Motorad. Personally, I'd go with an aftermarket non-Motorad.

 

[Lockasiam]

Sounds like it already has a Motorad thermostat in it.

You were correct!