pakrat

We have a 2006 HHR LT, with the 2.4. My wife bought it new with 7 miles on the odometer. Here we are 15 years later, and it now has 47k on it, so basically it rarely gets driven - my wife doesn't drive a whole lot, and it became the "spare" car a few years back. In fact it actually sat in the garage for the past 5 years, barely being moved and only being started every 2 or 3 weeks.

3 batteries (loving the fact that with no power you can't open the tailgate and have to climb through the back of the car), and set of dry rotted tires with less than 20K on them later, and I decided it was time to put her back on the road. It gets better gas mileage than my truck, so I plan on using it as my commuter.

After putting a new battery in it and getting it started with no issues, I noticed a wicked shake at about 60 mph. So I had the front brakes done (replacing the rotors), and replaced the struts along with the sway bar bushings - problem solved.

I then had the oil changed, and have since put about 1,500 (of mostly highway) miles on the car - always refilling the tank full with premium and adding a can of fuel treatment to help clear out the bad fuel. I hadn't had any problems, until the drive home last weekend.

I work away, with a one-way drive of 230 miles door to door every Sunday and Friday afternoon. As I got back into town and hit the "wonderful" Houston traffic this past Friday, I noticed the digital readout showed that the coolant temperature rose to the 195 range, spiking with a high of 204 degrees. It had held steady at between 187 and 191 the whole trip, until traffic backed up and I sat for a while. I assumed the coolant was either low or simply old. Saturday morning I checked the levels, the level at the filler neck was fine, but the overflow tank was nearly dry, so I filled it up with water.

Having assumed I would need to catch up on the typical maintenance items, and knowing a master mechanic who gives me a deal on labor if I supply the parts, I brought it to him to have the serpentine belt, hoses, thermostat, and water pump replaced.

When he quoted me $350 to change the water pump, I passed on it (for now). I also passed on the thermostat, the $100 price for labor made me decide I'll do it myself this weekend.

So, with the serpentine belt and all 4 of the hoses in hand I dropped the car off yesterday.

I picked up the car this morning, and now I have 2 problems:

1) Two of the four hoses I bought are wrong (because of course they are). Does anyone have a list of part numbers for the radiator hoses? I know there are 4 of them for some strange reason, but the "wonderful" parts clerks don't have a clue what they are talking about. Once I have the correct hoses which I'll get this weekend, I'll take it back and he can change them, along with a radiator flush and fresh antifreeze.

2) When I picked up the car this morning (with the serpentine belt having been replaced), the check engine light came on, I have no idea why. I am taking it back at lunch so he can plug in the scanner and read the code, but I would love to have an idea as to what is going on with this car ahead of time.

Oh, and although probably (hopefully) unrelated; it also seemed like the transmission is shifting a lot harder on the drive from the mechanic to work this morning, regardless of throttle input.

I know there's a lot here, but if anyone cold offer some insight, I would really appreciate it.

Thanks!

RJ_RS_SS_350

The hard shifting is caused by the Check Engine Light. There are many things that may have caused the CEL to illuminate, come back with the alphanumeric code. Perhaps the MAF sensor didn't get plugged back in.

The temp getting to 204* sitting in summer traffic is normal.

RJ_RS_SS_350

Since you say there are 4 hoses, I'm guessing that your 2.4 has the oil cooler.

GM part numbers
22728078
22728076
15241777
15241782

RJ_RS_SS_350

Here is the proper level for the coolant recovery tank.
https://www.chevyhhr.net/forums/main...ank-pic-55772/

And make sure the thermostat is the ACDelco part number 131-158. It's a little pricey, but it's the only one that gives no error codes.

pakrat

Thanks for the information, I genuinely appreciate it.

RJ_RS_SS_350

Just to be sure, check this diagram that the part numbers came from. #4, #8, #15, #20. Probably should replace #1 and #11 also. GM part numbers
22726953
22728077

pakrat

I took it to Autozone and they put a OBD scanner on it. The codes came back as:

P0102 – Mass or Volume Air Flow Circuit Low Input
&
P113 – Intake Air Temperature Sensor 1 Circuit High Input

I checked, and the MAF Sensor was not plugged in. So I plugged it in, then disconnected the battery for a few seconds to reset the system. The engine light is now out, and the hard shifting is gone.

Weird thing though, not a big deal, just a little odd. Before this mess, the car was often difficult to start. Sometimes I’d have to try twice to get it to fire up, but never a 3rd time. When the check engine light was on, she started right up with no hesitation at all. After I reconnected the sensor, she’s difficult to start again. I had assumed it had been because of the old fuel, but I guess maybe not. Should I think about changing the MAF sensor? Could that resolve the slow starting issue?

Oh, and I double checked – this HHR does not have the Oil Cooler. Maybe I was wrong about it having 4 coolant hoses. So I'm guessing the lower hose(s) is different?

Other than difficulty in access, as there seems to be in all cars; is there any reason I shouldn’t change the hoses and thermostat myself, once I get the right ones in?

Thanks again.

RJ_RS_SS_350

Ok, so the part numbers are
15241777
15241782
15270253
for #2, #7, and #14 respectively.

RJ_RS_SS_350

To drain all the old coolant out, you'll already have the lower hose off, and the thermostat out. So you'll need to remove the drain plug from the water pump. This is looking from under the vehicle, behind the engine, passenger side. That's the plug with the green paint on it.

pakrat

I can't thank you enough, seriously.