0ldchvygl

Hello, HHR’ers and Happy New Year!!

Am I correct that if the heater core valve hose is hard and inflexible, it needs to be replaced? Or is there a telltale sign that the valve needs to be replaced as well? I looked through the forum threads and was unable to find a similar issue…if I overlooked it, please feel free to direct me to the appropriate thread.

Symptoms and recent timeline: up until 2 nights ago, car (2009 LT2.2) looses water at approx 6-12 oz/40+ miles; before driving we top off the radiator with water and let it warm up to at least 150 degrees which appears to be the magic number that reduces event of temp display flatline (remedied by disconnecting battery). About a month ago, I placed cardboard in front of radiator to aid in elevating the temperature resulting in a usual running top temp of 180-190 degrees. 3 days ago I increased the cardboard size and as we were expecting freezing weather topped off the radiator with undiluted antifreeze. 2 nights ago the running temp climbed to over 212, I stopped, waited and added about 12 oz of water, the temp reduced to 186; a mile later the temp climbed back up and steam (with faint coolant smell) rose from the engine. After it cooled, a puddle formed from a steady drip (no gush) from towards the back of the engine.

With work schedule and weather, we haven’t been able to take a closer look but will tomorrow (weather expected to warm up to 40 degrees!!). We plan on taking off the wheel/wheel well to get closer to the heater core and firewall. I figured the thermostat and possibly water pump needed to be replaced but understood from researching on the Internet that it's better to wait until a water pump fails before replacing it. Is that the best approach, i.e. if it ain’t broke, don’t fix it? A friend suggested the issue isn't the water pump but may be the heater core valve hose. Any advice as to what to look for and how to efficiently troubleshoot this will be very much appreciated!!

donbrew

Your basic problem is the t-stat is stuck open. The temp gauge flatlines when trhe check engine light illuminates with a P0128 code.

There is no heater valve.

If there is a puddle under the car you need to find it's source, that is the leak. Might be the plug on the un used port on the T-stat housing.

Oldblue

Most likely the thermostat is toast, replace with an AC Delco 131-158.
Drain the rad and change the Dexcool.
To get to the heater hoses, it’s easier to get back there if you remove the air filter box.
Check for leaks the water pump drain plug.
When the heater core leaks there will be Dexcool in the floor mats

db2006

In Arkansas, there shouldn't ever be any need for cardboard to get the coolant warm enough. My 2006 will run at 194 to 196 after initial warm up when it's -15F outside. If yours doesn't warm up, it's likely the thermostat. If it's losing coolant without any external leaks you could have a bad head gasket or porous block. I use Zecol Mendtite in all of my vehicle cooling systems. It seals many leaks and won't plug up the system.

0ldchvygl

Hello, again, HHRers!!

Another page in the water pump/fluid loss/thermostat issue. BTW, my brother is doing the work, I'm in charge of research and purchasing. The outside temp is above freezing (been 20-25 degrees below normal here), so it's semi-bearable to be out working on the car. I'd like your opinions on the water pump, pictures included. In one of the YouTube videos I watched, the tech said that replacement should be a no-charge at a dealer; but the local Chevy dealer (who did the ignition recall items) said, no, "not with that VIN #". So, it's a known problem, a re-call item? The old impeller was totally disconnected from the shaft and wore grooves in the metal plate. Looking at the new pump, the impeller has a protective plate on it and in my opinion, makes the old pump look like a thin, cheap piece of equipment (biting my tongue here). In your opinions, is the old pump with its flimsy impeller SOP and not a recall item? Yes, it's a moot point, since the pump is off but might filling a complaint make a difference for other people with the same water pump? Your opinions/suggestions are appreciated!!

Thanks very much,
Oldchvygl

Cat Man HHR

I'm going to say that is an updated vain pump and it looks like a bigger shaft also. The stains/rust on the old one points to a cooling system that was not maintained. I would consider doing a flush to try to get that rust out of the rest of the cooling system. Your radiator/heater core is coated with it.

whopper

Yeah the rust stains alone tell of a sad life and lack of maintenance. Warranty? recall? nope, not a chance even without the rust.

As Cat Man HHR says, your radiator and heater core are coated - and hopefully aren't damaged too bad. I don't know if I would recommend a flush prior to refilling or not - it might be the kiss of death to the rad or heater... maybe?

That coolant needs to be changed at LEAST every 5 years - and DEXCOOL is the GM recommended coolant.

donbrew

Ha, warranty recall joke, right?

Pretty clear that someone thought DexCool was dangerous. And liked to use flush agent that are not recommended for aluminum.

BTW that is a after market water pump, your new one is closer to OE.

I don't know where rust comes from in an all aluminum system. Maybe the heater core is ferrous, I don't know.

Oldblue

Don, that impeller looks like it’s not aluminum!
A 2009, would be 9 years old now and I’m seeing signs of neglect, in that corrosion in the system, that indicates, at one point, someone put
A , just water to top up the rad, throwing out the 50/50 mix.
B , hasn’t changed out the Dexcool for Dexcool.
C , poured in the green stuff.

Now, I don’t see what came outta the rad, so I’m thinking these scenarios.
I do believe the water pump failed, was replaced with inferior part.
So, bolt up the new coolant pump, install a new AC Delco thermostat PN 131-158.
Pour in 50/50 mixed Dexcool, I don’t recommend mixing it yourself, but the premixed.
Make sure you burp the system , change the Dexcool, every 5 years!

donbrew

The more I look at it, that might not be rust it could be the residue from overheated DexCool or the red stuff. Only a chemist could tell for sure.

But the OE pumps have the enclosed impeller, like the shiny new one has.