Take your chances in a different thermostat, I’ve installed one of those Mahle 180 degrees F thermostats in my 2007 2.2 back in 2010, it failed after just 2 1/2 months of summer driving, I tested it on the stove in boiling water it opened at 180 F but it took longer to open than the AC Delco. The OEM thermostat had the inner oring distortion that blocked the thermostat from closing. The ECM was very upset and threw code P0128.

 

Thanks, everyone, for your help! The reservoir was almost full last night and it didn't leak at all until it got up to temp, and even then it was less than the previous night when the tank looked almost empty. I'm leaning towards the reservoir or the bottom connection to the reservoir as the cause. I will report back once I get this coolant issue resolved. Please let me know if you would like to me to create another post unless it's fine with the coolant questions living here under the Outer Tie Rods Sway Bar Bushings post. I can also create another post for the ABS/Service Traction issues, if you want. Thanks again!

 

Here is good

 

Thanks again for all your help! I successfully took the reservoir and reservoir hose out last night and inspected them both. I couldn't find a crack in the reservoir and the hose seemed to be in good shape, even filling with water and trying to get water to leak out. I decided to cut about 1/2" off each end of the small reservoir hose to get some fresh rubber and then reinstalled the reservoir. Took it for a test drive last night and then again this morning with no more leaks!! I will continue to monitor to make sure it's not intermittent since it was a small dripping leak and not gushing. While test driving, I hooked up my Bluedriver OBD module and monitored the coolant temp which got up to around 203 max and stayed mostly in the 190s so I think all is good. I plan on draining/filling the coolant once I know the leak is good. The water plump was replaced about 4-5 years ago so I think that and the thermostat are fine, so I would prefer not to mess with them unless I have to. Will just draining using the plastic drain plug be good or should I disconnect a radiator hose somewhere to quickly get the coolant out? Balancing the amount taken out and the amount of risk/effort is the goal.

Also, the Bluedriver OBD report now shows the below codes after a few driving sessions, but the CEL is not on. The brake, ABS, and traction instrument lights are still on. I will need to troubleshoot this some more.

 

For the brake codes, could still be hubs if they were sitting awhile or rodents chewing on the harness.
your coolant temp should be more around 180F , mine goes from 178 to 184 and back on a hot day. Could be the older coolant, could be the wrong thermostat installed, wait until you see code P0128, if ever, then change the thermostat.

 

Thanks oldblue. My list of repairs keeps getting longer but I think easier than the suspension. 😉

I’m not sure if the automatic transmission fluid has been changed so I’m thinking of changing it. Has about 148k miles and transmission currently shifts smoothly. Any reason I shouldn’t change it?

surely not all the wheel hub speed sensors are bad. At least I hope not.

 

Check the fuses and relays and ensure the four 7mm bolts in the under hood fuse box and the ABS fuses, here’s a map of the fuses and relays

https://fuse-box.info/chevrolet/chev...uses-and-relay

Just as an aside, I have repaired an ABS system issue with those codes, all 4 weren’t connected to the hubs. Another 2009, the hubs didn’t have the ABS wire and speed sensors at all, and my guy just bought the car two weeks before but his safety certificate expired three days after his purchase and ownership change, so can’t go back on shop because they said they didn’t know if someone else had replaced the hubs.

So look at the abs connectors first!

 

Yes, I checked the fuses and tightened down the four fuse box bolts over the last several days and all looked good. Initially I only saw two wheel speed sensor errors but now showing 4. I also verified both the front abs when speed sensors were connected and even disconnected and reconnected to make sure connections were good. Battery was bad and was just replaced. I’ll continue to monitor but. It sure where to start on the abs issue. The ecu is probably expensive.

Also need to decide if I should change the transmission fluid and where the easiest place to drain the most coolant out is.

im going to replace the valve cover gasket and spark plugs in the meantime.

thanks again!

 

Use the rad drain valve to drain the rad if your driveway is sloped, park with the rear end higher then the front to let air into the system, just unscrew the rad hose filler neck cap. The transmission fluid is easy if you have jack stands

A how to from our resident technical specialist

https://www.chevyhhr.net/forums/how-...-change-58325/

When you refill your radiator here’s another how to

https://www.chevyhhr.net/forums/how-...-system-60614/

 

Thanks! I'm going to work on the fluid changes, valve cover gasket, downstream O2 sensor, and spark plugs now since I have a good plan for those. The ABS/Traction control thing I'm still not sure what else to do, but I will think about it and do some more research for possible causes. I "think" I've checked the proper fuses and ground points, and the front wheel speed sensor wire connections and going into the engine bay all look intact and not chewed on or faulty as far as I can tell.

Again, thank you so much for your help.