[onyx10]

So what are "normal" coolant operating temperatures? You can monitor using the Cobb APv2 right?

[520]

One of the best write ups i've seen.

[itr_1211]

Do the tires really have to come off to change the coolant?

[STI Sibb]

Originally Posted by itr_1211

Do the tires really have to come off to change the coolant?

You can do it with the wheels in place, but it helps a lot with access to have at least the passenger side front wheel removed. I went ahead and removed both for easier access with the Undercover as well. The drain plug doesn't turn very easily sometimes so it helps to have room to move around and see what you are doing. If I had a lift like a dealership or mechanic shop, I wouldn't bother with the wheels.

If you try it, let me know how it works out.

[STI Sibb]

Originally Posted by onyx10

So what are "normal" coolant operating temperatures? You can monitor using the Cobb APv2 right?

I popped my AP on to test this since you asked. It read my operating coolant temperature (07 STI) at 188 to 190 degrees F after going WOT on an on-ramp. I would still monitor the system by the needle gauge on the dash when performing the coolant change as an added safety measure.

Here is what my Service Manual (07) reads from the General Section on the Coolant System concerning Temperature.

"The engine cooling system consists of a down-flow radiator which features high heat-dissipation performance, an electric-motor-driven fan, a water pump, a thermostat, and an engine coolant temperature sensor. The ECM controls the operation of the radiator main fan and sub fan depending on the signals from the engine coolant temperature sensor, vehicle speed sensor, and A/C switch."

There is a chart in the Service Manual (07) that says the radiator fans will turn on high speed if the Coolant Temperature reads 203-207 degrees F. That should give you an indicator of when the system will definitely cut on if it hasn't already. If you turn your A/C on, it will turn on much sooner (196-201 degrees F). The reason I've given a temperature range is that the Service Manual chart has more detail than can be described in a few sentences. I've left this portion out of the write-up as it's more technical than necessary to perform the service. It's still good to know that you can check it with the AP.

[19-Kilo]

Great write up, very detailed. A+

Add to sticky "How-To" catalog? here? http://www.iwsti.com/forums/how-inst...o-catalog.html

[Rennes]

Great write-up.

I'm having a problem understanding the dillution process. Blame it on my bad engrish

I have bought the conditionner and 1 undiluted coolant. You are saying I have to buy another undiluted coolant and poor both container in one big container and then add water?

[STI Sibb]

Originally Posted by Rennes

Great write-up.

I'm having a problem understanding the dillution process. Blame it on my bad engrish

I have bought the conditionner and 1 undiluted coolant. You are saying I have to buy another undiluted coolant and poor both container in one big container and then add water?

Hi Rennes,

Your coolant system holds about 7.7 liters. It is recommended that you put 1/2 distilled water (3.85 liters) and 1/2 undiluted coolant (3.85 liters) into the coolant system.

The undiluted coolant bottle you bought is 3.75 liters and is 100% coolant without any distilled water mixed in. You need to find a way to mix it with 3.75 liters of distilled water and then pour the mixture into your coolant system.

I recommend buying a 50/50 premixed solution bottle in addition to the undiluted coolant you bought. Your Subaru dealership should have both on hand. If you have the 50/50 premixed solution, you can pour it in first. Then you will have an empty coolant bottle to pour half of the 100% undiluted coolant into. You can check that the bottles are at half by holding them side by side in the light or looking down through the cap. Once you have the levels equal, fill both bottles near to the top with distilled water. Put the cap back in place and shake. You now have 2 more bottles of 50/50 premixed solution.

Does this help? Someone else might have another suggestion on how to do this.

[Rennes]

That's perfect, thanks STI Sibb

[Majin]

excellent write-up.