Okay then, answer me this. If your HHR didn't have any coolant in it. Which would be the faster way to fill it up. Through the overflow tank cap or the cap directly leading to the radiator? There is a difference.

 

That is your overflow/recovery tank and that is what you use to fill your HHR!
RTFM! On the past three vehicles I have owned (a 99, 02, and 06) there is no radiator cap. The radiator is completely sealed and the only way to add coolant is through the overflow tank. To my knowledge they do not put radiator caps on cars anymore, they are a thing of the past.

 

Thanks for the updates John... I usually watch my digital coolant temp reading, as opposed to the old analog needle. I usually don't watch it until I'm stuck in traffic (downtown Detroit) which is normally 80's+ on an average day... WITH 75%+ humidity. Although temps have run high(er) than what I'm used to... I've never had the vehicle overheat- and when the fan(s?) kick in it cools it back to the 190 range relatively quick. No leaks- just bubble sounds when I turn it off, etc... The only time I see *any* fluid under my vehicle is after the A/C has been on for sometime- just normal condensation.

I HAVE used (RedLine) 'Water Wetter' on previous vehichles (modified 5.0L Mustang GT and my rice-rocket motorcycle) with EXCELLENT results ! Looks like I may be picking up some more today in attempt to keep temps in a bit more reasonable range (according to my tastes... hopefully 195 max). This stuff REALLY works well. It's O.K. for aluminum pumps/blocks *IF* it doesn't contain silica - which will eventually eat away at aluminum and/or gaskets.

So- my new question, then, is how to add...
According to CJ in another post - there *is* a capped hose that can be removed to add fluid. I'm not sure I want to dump it into the overflow tank for fear it would take some time for 'all' of it to make it through/mix in the block.
Looks like I'll have to reference the (on-line) manual to see what's recommended.


*** JUST CHECKED THE MANUAL (ON-LINE) ***

States that you can fill either way- which makes sense. What doesn't really make sense is that you should only fill either of them when the engine is COOL!? No explanation needed - just thought that was wierd.

One thing to note- the manual states your vehicle is overheating when a.) steam is coming out from the engine bay, b.) the (analog) temp needle is in the RED zone, or c.) when the Engine Temp Light comes on (or any combination of these may happen at the same time)!!! SOooooo- technically (according to the manual)- the HHR CAN overheat WITHOUT steam pouring out from under the hood!?!?! Wonder what temperature set's the dash light off - or moves the needle into the RED zone?

 

I've seen 250 on the digital readout without any warning lights or steam. But this is hot and requires attention. I'd be very careful about opening the radiator cap (or whatever it is) that is on the short hose between the block and radiator. I suspect you could burn yourself badly if hot coolant starts spewing out. I've always added to the overflow tank, anything added will circulate through the entire cooling system after a short drive.

Has anyone found a "full" mark on the overflow tank?

 

Its on page 5-22 of the owners manual but it really isn't too clear when you look for it on the car.

Here is the Link Sindy put on the forum
https://www.mygmlink.com/pdf/go2cont...et/2006hhr.pdf

 

Pages 5-26 & 5-27 of the on-line manual states "if the coolant in the overflow tank is lower than the COLD line (when engine is cool), ADD coolant to the overflow tank."
It also states...
"If there's no coolant in the overflow tank (when engine is cool), ADD coolant through the pressure cap."

Bottom line... coolant in the tank is/should be recycled almost everytime the vehicle is run - assuming the thermostat opens. The fact that these vehicles *don't* have radiator caps, simply means they don't have CAPS (physically) on the RADIATOR itself. The in-line pressure cap IS (essentially) the radiator cap! Maybe we should call it an "Line-Cap"

For the record... there isn't a "FULL" line on the overflow- maybe a "HOT" - but this is based off of what I've seen on other vehicles. The reason there's not FULL (-or "Hot"... I'm assuming) is because you should never attempt to fill a cooling system when the vehicle is hot. Therefore- if it's full when cold, it must be full when hot (even though expansion, boiling, etc... occurs + assuming there are no air bubbles in the system).

 

Firewall area??
sounds like the heater core....

 

Look at the hose nearby the overfill tank coming from the radiator with the cap. That is the direct line to your radiator. You really don't know much about your car.


Anyways, the service light has come on and it is now in the hospital. For the one that didn't know about a firewall. It is what seperates the engine bay from the cabin.

 

No need to insult me. I probably know much more about my car than you. How long have you owned yours and how much of it have you taken apart? The fact of the matter is that is still not a radiator cap and if you look at the engine drawing in the manual what you are refering to is called a pressure cap and they warn you about playing with it. The HHR does not have a radiator cap.

 

Sorry if an offense was taken. A pressure cap and radiator cap are about as different as the Olsen twins. If your car is cold, there are no worries about taking it off. All I can say is if you ever have to change your coolant, have fun for the extra 1/2 to 1 hour it takes with your method.