Oldblue

It's not a bad job if you change the water pump and timing chain and the balance shaft chain

donbrew

You are all over the place now!
First you say is the engine is running at 226F then 219F (like the link you gave). 219F IS ok, 229F is NOT.
The cooling fan should NOT come on at 190F.

Go back (post #5) or search to find the description of the cooling system, it probably is in the link you gave. I get tired of typing it.

JazzDad

Everything has been working relatively well. Coolant temps, as displayed on the DIC would range anywhere from 145° to 232°.

So, here it is, 5 months later. 85 mile drive into town with outdoor temp of 68°F - I get the DIC flatline. On the way home, with 87° outdoor temp, now the CEL comes on, too.

Today, 58° outside temp, digital & analogue temp readings seem 'normal', and the A/C runs again, but the CEL is still on.

Could this be the coolant temperature sensor, and not yet another bad t-stat? I can't imagine that I could get this many bad thermostats.

whopper

And the code is? Surely you must know that downloading the CEL code is a necessary part of diagnosing the problem.

Oldblue

It might not be a bad Thermostat , just the wrong one!

AC Delco 180 degrees!

The others like Stant and Motorad don't open within the parameters of the ECM thus setting the P0128 code!

Don06

These cooling system threads are always interesting to me. My 2006 2.4 auto runs at 195 or 196 all the time once it runs for 5 minutes. Doesn't matter if the temperature is -20 or 95 outside. I flushed the Dexcool out after 2 years on the recommendation of the radiator shop we used for over 20 years when I was shown the problems that they only saw with Dexcool. I haven't changed the thermostat, water pump or radiator cap. I pressure test the cap every year and check the coolant PH. I run Zecol Mendtite in all cooling systems to prevent any leaks. You don't have to use a specific coolant in your car. A US law requires any manufacturer that requires a specific brand of product to meet warranty requirements to provide that product free of charge to cover the warranty period. It covers fluids and filters.

donbrew

GM does not require DexCool or any brand of DexCool. But it is designed for the alloys used in the engine.

DexCool is not a brand, it is a specification. Many companies produce it.

The "DexCool" problems were remedied years ago. There are tons of literature out there about it. Try reading some of the positive stuff.

One of the things that is only seen with DexCool is that it tend to get gritty or gummy when it gets overheated and needs to be changed, that is it's attempt to plug holes.

Good luck with your chemicals. I hope the radiator shop values your patronage.

We already know it is of no use trying to change your mind, but please don't tell people to go against manufacturers recommendations. Someone will always make a post like this one for liability reasons.

I have nothing whatsoever to do with GM nor does this site.

guppy

This is the proper tool that 843 is reffering to, you can grab one about $30. I have changed the water pump on an ecotec in under 5 min using this tool (yes, engine was OUT of the vehicle).


When the engine is in the vehicle, it is a little more difficult to access. I had a problem very similar to yours, after lots and lots of time and energy, finally discovered that the previous owner had used radiator stop leak and managed to plug up the heater core. We took one of the little 1 foot long heater hoses and bent it over and attached it back onto both barbed fittings coming from the thermostat housing. This made the car run normal, just no heater. You can read it here Anywho be sure to kill the engine if it hits 225° or you gonna warp the head, blow the head gasket or possibly warp the block. I advise you to take this little overheating issue very serious. I live in Dallas where it gets really hot, on the hottest of days with A/C blowing, I never see engine temp go over 205°. Winter months, no A/C it actually can hit 210°. For the most part my temp runs 188 - 198°. I have a 2008 2.2L, 2009 2.4L and a 2008 SS 2.0L.

donbrew

Here is a how to water pump. The price of the tool had come down a bit and I saw them in stock at Advance locally. But, the price is back up to over $45 and not in the store.

Here is a how-to with drawings and pix.

https://www.chevyhhr.net/forums/how-...acement-56476/

fastsuv

Did this issue ever get solved?

I am having a similar problem on my 06 2.4L.

After my timing chain rebuild and engine R&R, everything seemed to work fine. I replaced all hoses and water pump (New not reman) and thermostat.

Yesterday I was stepping through the DIC display while idling at a light and noticed the digital temp t 214. It went up to 216 and then the fan went on.

I have been closely watching the temps under all conditions the last 2 days. Before the timing chain repair, like Don06 says, my HHR ran at about 195 no matter the outside temp.

Now, there is no "normal running temp". It operates anywhere from 190 to 198 during normal running. During certain conditions, it drops down to 185. If I let it idle, it creeps up to 216 slowly and then the fan comes on. Once the fan comes on (at idle), the temps drop quickly (from 216 down to 190 in about a minute and a half) so there seems to be good cooling system flow.

A bad new pump would possibly explain the slow temp rise at idle, but not running at below normal temperatures while driving (185). I wonder if the thermostat is sticking in a partially open condition (unusual, but possible).

I am going to replace the thermostat first to see if that's it. I will get the good AC Delco unit from Rock Auto (which I think I bought last time).

The analog gauge shows the same reading when the digital gauge is at 185 or 216. I realize the analog gauge is not as accurate, but I should see a 30 degree difference. I wonder if there is a problem with the coolant temperature sensor for the digital gauge. Is the analog gauge a different sensor or does the same sensor operate both readouts? I'm at work and don't have access to my service manual.

Steve