Neither. It is likely that whoever manufactures the bimetallic component of the Motorad thermostats has the calibration wrong and the 180° thermostats are not what they're labelled as. There was nothing wrong with my procedure, as it worked fine the second time. The issue was the temp of the coolant reaching a level I wasn't comfortable with (or should have been required) before it opened. It was purchased to do the opposite however it is faulty. It works, and I'm sure you, me and Best 4X4, and anyone else who puts one in would not boil out their cooling systems however it does not open at 180° as advertised. Period.

 

Like I’ve said I have seen Motorad products boxed as 180F units and they were actually 195F units.

Auto Zone for example was very bad with 06-10 Hummer I5 H3 thermostats. They were supposed to be 180F units, and Auto Zone sold them as 180F units (made by motorad) however upon further inspection (which was difficult to say the lease on the I5 thermostat) they were 195F units. First time I had to question one was after the tricky install was already done..... In the end I had to buy an OEM AC Delco thermostat to actually get a 180F thermostat.

So it’s not really the quality of a Motorad thermostat itself, it’s their quality control. Thats why I always recommend double checking the temp stamped on the thermostat itself (sometimes that can be wrong too).

I’ve had a zero failure rate with the Britpart 180F so I just stick with that unit or the OEM grey unit.

 

If the consensus is "Wrong Box" then yea I could see that happening...but to have one manufactured wrong...that I dont buy.
I've had zero issues with every single motorad I've used. The people that I help haven't had any either.

 

Yep packaging issue for sure.

 

OK, so we're all saying the same thing here. In this universe there are 180° thermostats which DO NOT act as they are advertised. I was not arguing the point of them acting as thermostats. My very first post on the issue was clear that it did open in a pot of boiling water. Wrong box, quality control, improper manufacturing components, call it whatever you want. The bottom line is this:

Motorad 180° thermostats have a known issue of not behaving as advertised, or behaving like other manufacturer's 180° thermostats.

This is, was, and remains to be my issue, despite anyone claiming "they work for them". This is not an installation issue. It is a part that doesn't accomplish its intended purpose and therefore it is faulty. And as a result I will be repeating the task of coating my garage floor with coolant for a third time. Others may benefit from my struggle. I wish I had found this info ahead of time instead of finding someone saying, they work, you're just doing it wrong.

 

Then mail me your bad ones and I'll run them on my truck. I have bled rovers with "bad" motorads only to have them run the same temps as everyone elses.

You state motorads bad but then admit you never let it in long enough to cycle or see if it was an air issue. Cmon.

I just did my head gaskets, my temp shot up to 210. Raise the front, squeeze some hoses, bleeder, turn on the heat, fill the jug that I dont bother raising and bingo, truck idles at 206, no heat on, electric fan doesnt even kick on. I left it sit for a half hour...electric fan didnt kick on. Step on the gas, or drive truck stays around 197.

I have absolutely no clogs anywhere. I ran a snap on borescope down every nook and cranny, in the rad, heater core.

I emailed motorad...I want them to know if there parts are messed up. I am waiting for a reply.


The cooling system, the way it was designed, will never run at 180. Gas mileage starts getting bad at 180...well, worse. A rover can survive at 210-220. It means you have AIR somewhere or possibly the little seep holes are clogged, which does happen.

Remember, at startup, the temp displayed is not the thermostat temp...it the sending unit temp. You have to drive it awhile or let it idle initially. Dont freak out if it starts going into the 200's. Just don't let it go to 240 for long.

Funny how there used to be motorad lovers here, that's all they would talk about...but those people are mostly gone.

 

Yeah a lot of the other threads with bad stats are likely air, bad temp sensors, or incorrectly labeled temp thermostats. An INOP stat will either stick closed or open. If it opens/closes it’s either the wrong temp (I always verify the stamped temp on the inside of the thermostat), air in the system, or a clogged radiator.

I have yet to have issues with a thermostat (only when I find nearly 20 year old OEM thermostats). I add coolant let the temps get up to 195-205F, let it cool, top off thru the bleeder (if it still has it), and repeat one more time. Then I drive it and have zero gurgling, and temps on the road at 55-65MPH is 188-193F easy in SETX with 100% humidity.

 

I will say it one more time. I did not say they were bad, I said the opposite. I said they worked, just not as claimed. Repeating the same process with the original thermostat did not produce the high temps seen with the Motorad. I should let a colder thermostat drive the temps higher before it reacts? Explain to me why the original thermostat opened well before the Motorad after I reinstalled it. Air pockets? Each were bled the same way. As I already said, every hose was hot and I could observe good flow everywhere.

I also did not say I "never let it run long enough to cycle or see if it was an air issue", those are your words. I said once the temps climbed to a level never seen by me before on this truck I shut it down. It ran for 10-15 minutes while I was checking the trans fluid level. The fan also came on, which is what alerted me to the issue when I heard it. There were no bubbles under the bleed screw, the heat was blasting and all the hoses were hot with the exception of one. The lower radiator hose. When I put the original thermostat back in the truck, repeating the same install procedure, the temps never climbed, the fan never came on, the same flow patterns were exhibited, and the same hoses got hot, including the lower radiator hose. This is because the original thermostat opened before the Motorad. You're offering ifs and and vague statements and I'm giving you facts about my experience. Explain where you theorize these air pockets existed.

Neither of the second statements applied to the original thermostat. Zero. Well of course you have to let it idle initially but that goes without saying. And all these things can be accurate statements, but if this is what Motorads require then they're not for me. It's going back to AB, for whatever reason they agreed with my assessment that it's not performing correctly. I don't disagree that typically improper installation will cause funny things, air pockets are real, and cooling systems can be temperamental, but I'm telling you this was not the case. I'm simply not buying your claim that "it was done wrong". Agree to disagree I guess.

Bingo. There's nothing stamped in this unit (wonder why), there was no air in the system, and the radiator isn't clogged. So.... I stand my my statements.

 

The 180 Motorad I got that acted like a 195 was also purchased from AB.

 

Did it keep the system around 197-201?