So heres what I am dealing with.

I have a 2006 Chevrolet HHR. Its been in the shop 3 weeks this month. They tell me that they CAN NOT get this car to fail and overheat but every time that I take it back from them, I drive down to SFO and it overheats.

Whats been replaced with reasons;
Head gasket (was missing and leaking)
water pump (was leaking coolant out the back of the water pump)
cooling fan (power going to the fan, but fan was not coming on)
cooling fan relay (cheap so I replaced it)
t-stat (180 deg murray t-stat)

What I found out today as it was overheating;
I was driving noticed the temp gauge starting to rise, wasnt worried since it just got out of the shop and they said they hadn't been able to cause it to fail and overheat, I watched the degrees climb, 221-223-225-228-230, I started to worry and I got out of my car, popped the hood, fan wasnt coming on, back into the car, 232-236-239-241, panicking I turned off the car and the fan even with the AC on, the fan wouldnt turn on.

Now my question is, could this be caused by 1, 2, or 3 different temp switches in this car? I know for a fact that there is a coolant sensor, but that seems to be working just fine. Is there another sensor anywhere on this vehicle that could be causing this fan to not turn on? After all its brand new!

 

Have they checked the coolant for "combustion gasses", or have you? You can pick up a kit at you local auto parts store, you might need to seek out the most experienced clerk, otherwise expect a dumb look from the counter guy/gal.

With the cooling fan failing to activate even with the A/C engaged, you may have a multiple layer problem such as a failing ECM and a cracked or warped head.

I remember your initial thread on this, but my memory is failing at bringing up whether you're using a dealership or an independent shop?

 

Here's an idea: take it to a shop and tell them to call you when it is fixed. Don't tell them what's wrong, just "it overheats while driving" let them diagnose.

When the temp gets to 240F the CEL should come on some sort of message on the DIC and go into limp mode. Limp mode only fires every other cylinder and the trans will not shift out of second.

Can you jump the fan relay and force it to run? Typically the switch is to ground, so checking on ground connections would be in order.

 

@donbrew

Ive taken it to 3 different shops with the overheating as the issue, thus the new cooling fan, the new head gasket, the new waterpump, and me changing out the new relay.

Just got it out of the dealership on Tuesday, they checked it, and ran it in their stall, not only ran it in their stall but drove it down to the city just south of here (5 miles each way) and said that they could not get the car to fail. Not only that they told me that the fan would not, not turn on to cool down the car.

Not only that I have told them to only call me when its fixed. And yet this issue keeps on persisting and is driving me absolutely NUTS.

@843de

Its been in the shop for a replacement of the headgasket, they sent the head off to the machine shop and the machine shop said that everything was in complete working order no leaks, no cracks, and pressure tested just fine.

When I got it out of the dealership on Tuesday they had also said that there where no leaks in the system and it was holding pressure 100 % no leaks, cold or hot. Which means that there cant be any "combustion gasses" with zero leaks.

How ever if it is the ECM that is failing, is it an easy fix that even I could do with the person/place I buy it from flashing it over to the info they need on my car?

Also I was wanting to know how many coolant sensors there are on this car? If anyone does know?

Also with this "limp mode" I saw absolutely nothing on the CEL where the temp reading is. It just kept going the same.

 

Well a failing ECM needs a technician armed with a Tech II scan tool to interrogate it and determine if it is in fact failing. The physical replacement of the ECM is not that hard to do, but the replacement will need matching to your HHR's VIN etc. So we cycle back to the technician and his trusty Tech II.

There is only one ECT(Engine Coolant Temperature) sensor, and if your temp gauge and DIC aren't flatlined, it's working. But is its signal being interpreted correctly by the ECM, back to the tech and his Tech II again.

Even though the head has been off, checked, and pronounced "good". There can still be an internal leak, hence my question about combustion gasses in the coolant.

Now when it overheats, are we talking at highway speeds, town speeds, or sitting in traffic?

One other question, are you running the recommended Dex-Cool coolant? Or is it filled with the "green stuff" AKA Ethylene Glycol?

At anything but a crawl, HHR's rely on "Ram Air" cooling, the forward motion of the vehicle rams air through the condenser and radiator, so is the airflow to your radiator impeded. Or is the radiator itself clogged up with sediment to the point of being useless.

If it were mine, I'd look for a shop that specializes in nothing but cooling system work.

We understand your frustration, and there is a solution out there, but I think we'd all agree on taking another approach and thinking outside of the box a bit.

 

In the last thread which was closed due to inconsistencies and new revelations that kept being thrown into the discussion, now with this new thread you say the fan doesn't come on - when before you were having problems with the fan not turning off?

If you just had the fan replaced and it doesn't work - take it back to that shop. You say you haven't got money to throw at it, but that is exactly what you are doing.

Taking it to three different shops over what amounts to the same issue, or at least related issues, is not the way to resolve it. Sorry this isn't making any sense at all.

Sorry - this thread is closed - if it as complex as it appears, we can't help you any further over the internet.