2006 HHR 2.4 Auto 174k miles

I've been dealing with a weird issue with my HHR's cooling system, This car ever since I bought it has run usually pretty warm but only on the highway or at/above 60mph or ~2,800-3,500 rpms. In the city I see about 195-200 and on the freeway it hangs about 210-215. If I'm going over 75-80mph the engine is usually right about 3000RPMS and over about 30 minutes it'll slowly creep from 210 to about 230. It's crazy 230 is barely halfway on the gauge! If I pull off the freeway and stop the car the temp even with the A/C still blasting the temp goes right down to 190-200 again and has no problems. As a torture test (gave it an Italian tune up afterward) I let it idle for 6 hours straight on a hot day around 100-105f outside. Adding more torture for the test It was also sitting in the sun with the A/C on full blast. Didn't get a lick above 210 so I don't know what the heck is going on, I've never ever let it overheat or go above 235 I just stop or slow down to under 70 and it creeps back down. This also only usually happens on hot days or climbing grades, hasn't happened at night or when it's cool out, yet.

This is the work I've done so far for the cooling system,

Coolant drained and filled, it had the correct coolant but have no idea how old it was, could've been original.
Thermostat replaced with a Delco one and used Delco DexCool, their coolant prices are ridiculous.
Rad hoses replaced (they were original it's insane they didn't pop)
Coolant burped using the nose high method
Fan works perfectly and heater works perfectly.

I'm worried this is a failing water pump which is gonna run me around $600 to have replaced :sob: I've tried searching and the overheating posts I had found were either the opposite of my problem or their fan not working, so I do apologize if this has already been discussed I just couldn't find it.

Thank you for all your help this forum is amazing!

 

If the fan is working correctly; it should come on at about 217F or if the AC compressor is running (defrost will turn it on).

Why would it cost $600 to change the water pump? Flat rate labor is 4.5 hours, if you could do all that other work you could do it yourself.
https://www.chevyhhr.net/forums/how-...acement-56476/
Any brand of DexCool is OK.
The correct Delco t-stat is 131-158 NOT the cheap one.

 

Thank you for this info! Taking a look at those instructions this job would be way outside of my comfort zone, maybe if it was a second car but I've never messed with timing components or anything that advanced and can't afford me screwing something up and it being FUBARed. Since it's timing driven when it fails will it destroy the engine like the Ford 3.5? That's my fear as it may already not be doing great and if it fully fails it'll just pump all the coolant into the oil. The shops I could find with positive reviews in my area charge about ~$125/hr plus marked up parts and since they'll be in there I should have them do the chain/tensioner/guides I'll actually probably be looking at just under a grand. The fan does come on around that temperature and comes on immediately when I turn the A/C on.

 

I wonder if the airflow through the radiator is partially blocked. Maybe someone installed an aftermarket transmission cooler in front of it?

 

I've also never checked to see if it was full of stuff either :doh: I've used A/C condenser cleaner on radiators/condensers before and had good results, I'll give it a good cleaning and check for obstructions.

 

The point of the "special tool" is you don't mess with the timing chain, it locks the sprocket so you can remove the pump leaving the sprocket in place. You don't take the front cover off unless you are changing the chain & guides, then it is easy to do (about 15 minutes more). Just causes over heating not thrown chains.

The weep hole is in a recess on the top of the pump, GENIUS!

 

Temp getting up there on highway but not idling, with AC on, could be timing is off , but then again it could be air trapped in the cooling system, how many times did you burp it?

 

I read those instructions very wrong. Oops!

 

Just once, I'll try a couple more times, maybe it just needs a little more.

 

It sometimes needs five or six burps.