Thanks for posting this Smokewagon. 2007 HHR 2.4 original owner with 77K miles. A/C and gauge cut out this weekend. when it cut back on, the digital reading is very low - 160. so I must have a bad stat. Thanks for the detailed r&r.

Thermostat problems!
 

I had this same problem on a 2006 Malibu SS 3.9 V6, the thermostat gasket can easily be rolled over (which this one was) during installation. This results causes the thermostat to not close completely and engine not to ever reach the temperature the engine temp. gauge needs to see resulting no power to the A/C compressor. Granted this may not be the same on my 2011 HHR, but I'm willing bet the thermostat/gasket design is the same. One last thought concerning the thermostat I now use only an A/C Delco brand after reading other owners having so many problems with other brand thermostats. This is not to say other brands will not work but know the one I removed from the 2006 Malibu SS was not an AC Delco design, it was from who knows sources

361 days after replacing my factory-installed stat, this one seems to be going. (I figured, hey, the original lasted 7 years, why not put in another GM 12622410?)

Yesterday= outside temp 100° F, coolant swung between 153° and 181°. Today= outside temp 77°, coolant varied between 158° and 181°. Later in the trip, it stayed around 180°.

Maybe it's the sensor this time? (Just reading low?) But if that's the case, why the big variation while I'm driving? (And it's not getting up to that 193° area.)

(Fortunately, it hasn't shut done the A/C yet!)

Comments?

Air still trapped in the system?

It's a simple enough job to pull the current thermostat and check it to see if it is jammed open.

My guess is t-stat center gasket failed, the t-stat is stuck open, anyway. I believe that number is the old design.

This shows four other superseded numbers, but doesn't detail which is the latest version

GM OEM Engine Coolant Thermostat 12622410 | eBay

Two days in a row it's been fine. WT....?

I burped the system when I replaced the stat. (Recognized that gurgling sound in the dash.)

I think I'll go with a Stant next. I e-mailed them asking what the difference was between their 14698 and 48628, but haven't gotten a reply. Both are spec'd for the 2.2L, and are to replace the OEM by part number. (And it costs less than the GM part.)

Did you read any of the preceding 12 pages?

The after market t-stats and the older GM have a rubber gasket on the valve, The new GM has metal on metal seal at the valve. You can see it in the pic in #126, the center not the housing gasket.

It is that rubber gasket that fails.

The difference in the Stant numbers is the medium used in the plunger. One is wax the other is something else.

The GM part is cheaper or within a dollar on eBay the last time I needed one. When you are talking $30 does $2 really matter to you?

I just picked these at random.

I'm out! I've replaced at least 7 Stant's

Yes, Don. I have read all the pages. (As a test, just ask me a question from any of them.) I used the instructions for my replacement a year ago.

It would appear that I got the old style, then, although supposedly redesigned in 2015. (I guess someone unloaded their old stock on me.)

You know there are still folks on-line selling the OEM for $50 and up? The Stant can be had for about 13 USD. But if it's still garbage, that's no bargain at all.

Is that 12T103D the latest iteration?

To my eye it looks right Stant 14698 claims to be a replacement. 12622410 also looks right, that is a Saab/Chevy p/n. 131-158 also looks right.

I don't know when it was re designed, but I know that the one I took out of my 2011 in 2012 was the new kind. That's when I became aware of the difference.

There has been a lot of p/n consolidating going on, so it's hard to tell without eye contact. There have been a lot of 190F t-stats getting sold by GM lately,too. I don't trust parts books anymore.

I know without re reading the whole thread that "get OEM because the center gasket is a problem" was mentioned several times.

I'm sorry to be beating this dead horse to death. (Wait, how can you do this?)

So which is the latest or best one: The 12T103D or the 131-158? One of the other moderators seems to favour the 131-158.

I don't know they seem to be the same, different factory.

ZZP has this

Ecotec Parts Ecotec Thermostat

There is this from Amazon

https://www.amazon.ca/Genuine-126224.../dp/B00GUHB8MG

Or the AC Delco

https://www.amazon.ca/ACDelco-131-15.../dp/B000IZ25VY

I've recommended the ZZP at $14.99 many times!

Well, the one from ZZ Top is cheap, but I've also heard negative things about Motorad.

As Doctor Smith would say, "The pain, the pain".

Anyone know how tight to torque back those T-stat housing bolts?

Thermostat Housing to Block Bolts 10 N.m or 89 lb in

Be careful. The housing is soft pot metal and easy to strip.

OK, am I stepping into the same cow pie again?

Did I manage to buy someone's old stock? It would appear it was made in March of this year.

That is the old stock with the old rubber gasket so yup! Cowpie!

I searched here Search Chevrolet HHR Hatchback Parts

12t103d turns up no results, makes me think it's probably the older design.
131-158 turns up the thermo. But I couldn't find any pics online with the viewing angle that you took, to see if that inner gasket was there.

Now when I searched the ACDelco parts catalog ACDelco Parts , it says the 131-158 is GM original equipment, and the 12t103d is ACDelco Professional.

When I googled your 461-180, all I could seem to find was MotoRad.

I Googled 19137281, no picture


Thermostat Asm Eng Cool W Gskt - 19137281 - Cap Stats - GM Parts - by Genuine GM - Thermostat Assembly

Live and learn.

From the ACDelco website ( About Us: ACDelco Auto Parts, Auto Repair & History ) "Our GM Original Equipment auto parts are the original parts for GM vehicles and meet or exceed GM OE specifications. ACDelco Professional aftermarket auto parts and products cover most GM vehicles as well as many other makes and models. ACDelco Advantage products offer fit, form and function for most makes and models at a more affordable price. For some auto parts, we also offer a Specialty line." [By implication, their 'Professional' line does not meet the OE specification. In other words, they fit but they're %#$@!]

This is my new thermostat. As you can see it's the 131-158 new style.
Look close it still has a small rubber o-ring.
$31.89 from rock auto. GM P/N 12622410
I'll give it a try and see what happens.

At NAPA anything with "pro" on it means the same as "contractor" at Home Depot; Cheaper stuff so you can make more profit. A devious marketing ploy.

I got a 131-158 off the bay for $27 (shipping included) coming tomorrow. I lost $6 sending back the "pro" piece.



It would have been easier to rig up some louvers in front of the radiator, moved by a control cable mounted in the dash. (Depending on your age, you may remember when mechanical chokes were operated in this manner.)

Which way does it sit. I forgot to look when I took mine out.

jtfrog!!! Please stop posting the same question in multiple places!!!!

this thread closed.