Read tons on this and still?... It's a 2008 HHR. 2.2, LT, Automatic... Rabbit Trails... started here, replaced the leaking fuel tank AND the fuel pump (NOT a GM) soon after that I got a code PO 451- Fuel tank pressure senior. After a delay I got a GM- FTPS, dropped the tank (second time) and replaced the FTPS on another new fuel pump. Still not a GM fuel pump BUT never had a fuel pump problem. Someone PLEASE SHOW how to REPLACE the gas tank as I worked an hour or more to replace it both times... PLEASE! NOW... before replacing the fuel tank (pump and FTPS) the second time, WHEN out driving around, I notice the Radiator FAN running a lot at all temps??? It would sometime come on at start-up and off and on at other times? It always turned off when turning off the engine, didn't continue to run even at 217 F, after turning off the engine. The PO451 code on the FTPS has not come back on after about 2 weeks but it's been a short time... will see. NOTE: On putting back the tank I found the Evap Charcoal Vapor Canister AND Canister Vent Valve full of road dust / dirt and I'm in the process of replacing both as sure the vent valve has not been working / is not working now??? The attention now has gone to the Rad. Fan running lots. After studying it I replaced the Temperature switch (used GM) in the block next to the thermostat. ON START-UP it showed a code P0118 Engine Coolant Temperature (ECT) Sensor Circuit High Voltage???? After a day and a half it went off by its self... I read that on GM cars this can happen, the fan stays on and you must clear / delete the code and all will be alright after that. Mine went off by itself and has worked normal for pass 3 days, then today started staying on all the time after a half day of not! NOW the hard part... This morning I checked the coolant and all was good. Went 3-4 miles to tire shop and left (outside temp on the dash read 95F)(engine temp 180F)... NO fan... went about 25 miles (Hwy) and stop for 45 min... NO FAN... Went another 7 miles (Stop and Go) and stopped for 35min (outside temp was 100F)(engine temp 183-185F)... No FAN... THEN went for about 25miles (Hwy) and the FAN was on when stopped ... the temp on the dash (outside temp) read 110 (engine temp ran 183-185 all the way there?) ! After an hour at that stop the fan turned on at start up (Eng temp 160F)? Stayed on until the next stop about 8 miles (Hwy mostly) down the road. Also to note... week and a half ago /back I was going home around 6:00PM, before the second fuel tank drop job and the car just cut off, gas pedal did noting when pushing it. Can't remember any dash lights... engine dead. Rowed to a safe spot, tried to start it twice and it was like it was out of gas. Outside temp 100F easy AND engine temp was 185F. Checked the gas pump fuse, was good so change the fuel pump relay with another and waited an hour.... it started right up??? When I got it home I changed the relays back and it stilled started and ran??? Replaced the relay with a new GM. I have replace the
fan relay with another also. The HHR has sit for about 3 hrs. and will go see if it will get me home or ???? Does any one see a problem with the fan? Is the fan two speed or one speed ? Tried to write this to cover all the details but never do. Thinking / hoping the temp. sw. would fix the fan but??? I replaced
the thermostat about 12-18 mos. ago (GM I think) if not could that be the problem? The gauges on the dash and on the LED read-out seem to be working as always... the dash gauge never moves once warm up at about mid area... the LED one moves all the time, stop or slow down and it goes up, speed up
​​​​​​​and it goes down... since the temp. sw. replacement and the fan was not coming on, twice when coming home I noted the LED gauge was at about 215F, watching it go to 217F and the fan came on as it was to have done??? Looked like all was in order... then today, again the fan is running at low temps. From 160F, 180F, 185F etc. Who know what another day will bring... PLEASE think of the complete picture here and all the angles. Thanks for all help!

 

Test the fuel pump, a test gauge should be available at your local parts palace.
double check the coolant level there should be no air under the rad cap.
If you’re not sure about the thermostat, you could change it and install an AC Delco 131-158 180 degrees thermostat and fresh 50/50 Dexcool. Then burp the coolant.

 

Could you please restate the problem in a couple complete sentences, "just the facts ma'am". I cannot read a wall o' words, due to recent cataract removal. All I can see is a bunch of blurry letters with some bold words.

 

The AC compressor (and therefore the cooling fan) will run with the AC on, or in recirculating mode, or in defrost or floor positions.

You should make your extra long post with paragraphs, that is a really tough read, very easy to miss an important detail

 

Succinct works for me. As soon as I glanced at it I moved on. I'm old.

 

Update: Got back on the road last night at 8:00, outside temp. was still 100F and engine temp. was 130F. Fan never came on during the 10 mile drive back, no problems.
Today... checked the coolant level, it was alright. On start-up NO fan, after a short stop and then down the road for about 6 miles and a stop for gas, fan was back on. The outside
temp. is back to 100F and going up.

Please note that I have not been running the AC... but saw a video saying the AC Low Pressure sw. can cause the fan problem... and if not then try the High Pressure sw. Said this
was a GM on- going problem???? The blue and red dial (cooling and heating control dial) on the dash is messed-up on the cooling side. When at the max cool setting at the bottom of
the dial (all the way to the left, blue area) the air can change from blowing cold to blowing hot. By playing with the dial a little it will go back to cold... They don't sale just that one dial so
have to get a used 3 dial set. Will look into that as being a problem...

Again ... if there is a good part... on the Hwy the temp has stayed around 185F (and the fan is on) .... Only when you slow or stop does it go higher ... and the fan is still ON! ????
Tomorrow is to be the last day in the 100's so want to see how it acts in cooler weather like it does in the mornings and nights.

 

Keep us posted

 

Still a wall o' letters.

 

Another up-date... Lots of research and found some with a fix by doing many things from AC HIGH and LOW PRESSURE switches, to coolant temp. switch and thermostat replacement. Which I have now done as I get the coolant topped off.

Now the radiator fan has stopped running which was the main problem... AND the HHR has NOT gone dead on the side of the road any more.

But going down the freeway this morning I got a new LED note saying to "check the gas cap." Only stayed on no more than 2 minutes, pulled over checked it, was OK so put it back on at 3 chicks (have put on 3 so far and has a new AC Delco on it now. Nothing more on that....

Tomorrow I have a new charcoal canister and vent valve to change out to end the Evap. hunt I hope. Found them both full of white dirt/ dust when replacing the Fuel Pump back a week or so.

Question for today is... could I have a bad Filler Neck that set the "Check Gas Cap" sign??? Or would a bad Vent Valve not working be messing-up the Evap. system to the computer??? Check for codes Friday and nothing there. After the work tomorrow I hope to get a scan tool to look at all ... Let you know friends. Thanks JC

 

There could be junk on the lip of the filler or the rubber gasket on the cap might be worn out. I would start with easiest and cheapest; take a scrubby to the mouth of the filler and get a new gas cap.
The fan is supposed to run all the time if the AC compressor is running It runs in defrost and if the recirc is on with no warning light. The fan will run after shut down if the temp is high enough