ACDelco VS Motorad-not all thermostats created equal
 

So I needed to change my thermostat and I ordered an ACDELCO one here, thinking I'm buying a great brand:
But when I got it, it had MOTORAD stamped on it.
Anybody ever heard of this before? I always thought Motorad was a third rate option so I thouht I got ripped off.
I contacted ACDELCO via facebook and after a couple of weeks they replied with:

"Hi, Todd. Our internal resource informed me that Motorad is contracted with ACDelco to manufacture parts to ACDelco specifications. If you have any other questions, you can always ask us here. " -Rhea J.
So apparently, there are two ACDELCO thermostats that fit! But I, and you, need to buy the 131-158 version. Because only one is made to GM specs, the other (12T103D) is made to specs pulled from someone's rear. Why even do that? Why attach your brand to that?

I ASSUME that Motorad has nothing to do with the 131-158 thermostat, but I could be wrong. Anybody?

The one you got is the $15.00 professional one, for used car lots and shops that just put in the cheapest part!

The 131-158 is considerably more expensive.

Yes, we know there are 2 AC/Delco t-stats; that is why we almost always state "131-158".

AC/Delco rebrands many items just like all the others.

The 131-158 has a very different design seal on the valve portion.

& believe it or not, the car knows the difference. This I know.

Me to, I’ve gone thru a Motorad and a Stant, then opened my wallet and purchased the AC Delco $15.00 professional, that failed in 2 weeks, then the 131-158, it’s still working just fine since 2012.

I had a nearly new 131-158 fail last Friday on a 1000 mike road trip. I failed locked closed. I used a pair of cutters at a gas station to remove the spring so I could make the trip home. I was stuck with a too cool of an engine by a bit but I made it home. I think the better acdelco is made by stant. Stants top model looks identical.

I haven’t driven the car since I got home but I need to get a new thermostat and get it swapped.

How did the wax escape?

Explain please.

The MotoRad thermostat in the AC Delco box, could have been from a return, mixed up boxes.

Wax is the motor in a t-stat. When it melts it expands opening the T-stat opens. For it to fail closed the wax has to disappear from the capsule.