fastsuv

My 2006 HHR is having the stuck-thermostat problem.

I am going to replace the thermostat and the coolant.

I have the service manual and have read the forum how-to.

The question I have is should I pull the drain plug at the water pump?

The service manual and the how-to in the forum say you can if you want.

Should I?

Its probably a more thorough flush, but I hate to mess with a drain plug that has never been removed before and chance stripping it.

Steve

donbrew

It is a pain to get to and a pain to remove and a pain to replace, and it only gets you a few ounces. If you are "flushing" the old stuff will be gone by the third change.

You will get a face full of coolant/water and the thread sealant they use is like a weld. Do it if you have the energy and patience.

hurst2001

Well try to remove the lower hose got a lot of plastic to remove but worth it,forget about the drain plug nothing but plastic junk to break,also you will remove the other hose were the thermostat sits by the driver side and you will get most of the fluid drain but not all ...when you refill make sure that the front end is a little higher then the rear and pour in slow less air to get into system ..that's how i did mine

fastsuv

Thanks for the replies.

I plan on not removing the pump drain plug.

After draining the coolant, I will refill with water and run the engine until thermostat opens up. This fill/drain cycle will be repeated about 4 times or until the drain fluid is clear.

After that, I assume any fluid trapped in the engine will be water and I need to adjust my fill fluid(dex-cool vs water) accordingly. I will add all the required Dex-Cool for a 50-50 total mix first, then top off with water. This should ensure the final mix is 50-50.

Does this sound right to those who have done it?

Steve

whopper

Sounds good - when I did it, I drained the rad via the petclock at the bottom of the rad (passenger side).

Just be careful with it as it is plastic. You can't see it from the top of the rad, but you can find it by feel. I found it much easier that way, than removing the lower hose to do the draining.

hurst2001

make sure you use distilled water not tap ,you will be fine

firemangeorge

So, using these capacities from the owners manual, I come up with:

Engine----------2.0----9.2 qts. Half is 4.6 qts.
Engine----------2.2--- 7.4 qts. Half is 3.7 qts.
Engine auto-----2.4--- 8.5 qts. Half is 4.25 qts.
Engine manual --2.4--- 8.7 qts. Half is 4.35 qts.

It figures. To get the exact 50/50 ratio, you will need a little more than a gallon to get it correct in 3 of 4 of these.
Does Dexcool come in small containers? Or, do you need to purchase a whole 2nd gallon.

fastsuv

I was planning on distilled water, but I have to remember I need to buy enough to cover 4 flushes plus the final fill, which means getting about 10 gallons. Lucky it's cheap.

As for the 4.35 quarts of Dex-Cool, looks like I will have to buy 2 gallons. I have only seen the coolant sold in gallon jugs.

Steve

fastsuv

One last thing: Is the hose clamp on the thermostat housing reusable or should I buy a worm-gear clamp to replace it?

I know it should be reusable but has anyone had leaking problems after reusing it?

Steve

donbrew

What I do: flush a few times, then add 1 gallon of straight DexCool then top off with water. Since the capacity is about 2 gallons that gives a 50/50.

The Service manual gives conflicting recommendations on the water, at one place it says "potable" and in another it says "de-ionized", no mention of distilled (not exactly the same as de-ionized). I have soft river water in my tap, so I use it.

Also, be sure to take the overflow tank out and dump and rinse it. A lot of residue gets stuck in the bottom and clogs the hose. As far as I can figure BTW, the overflow tank is included in the fluid capacity. Disregard this paragraph if you have a surge tank.