Changing Coolant Questions - Third Generation F-Body Message Boards

Saabster · 09-25-2009, 01:39 PM

So I'm changing the coolant in my 89 this weekend. The car is running cold (bad for the emissions test I need to get it through) and I figure the previous owner didn't do it (no clue). I also want to convert to a more modern coolant with a higher % of water. I have some questions about how to do this.

1. What's the approximate capacity of a stock cooling system with a 305?
2. Can you easily drain all the coolant at once or does some remain in the block? Any tips or tricks? (example, my saab only lets you drain 2/3 of its coolant at once)
3. Can the system be easily refilled? How do I purge the air? Any tips or tricks here?
4. A bit unrelated, but my fan stays on constantly, any suggestions as to how to fix that?

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Richwiz1 · 09-26-2009, 12:34 AM

what thermostat are you running? Capacity should be around 17.2 quarts. Some of the coolant will remain in block. To refill it and purge the air refil rad turn heater to full blast let thermostat open then refill till full put rad cap backon should do it.

Saabster · 09-26-2009, 07:55 AM

I don't know what thermostat I'm running. It's whatever was in the car when I bought it a month ago. This is most of the reason I'm changing it.

Thanks for the rest of the info though.

spurgeon76 · 09-26-2009, 08:03 AM

You can by a kit to flush out the system. It basically lets you run a hose thru the system and flush out the old coolant and gunk. You can get it for less than ten dollars at walmart or autozone.

Richwiz1 · 09-26-2009, 11:27 PM

Stock thermostat calls for 195 degrees lot of people run 180 degree good for summer or winter. As far as fan problem check make sure previous owner did not rig them to run that way both should only run when a/c is on or extremly hot. The thermostatic fan should kick on around 238 degrees.

Saabster · 10-05-2009, 01:45 PM

Quote:

Originally Posted by Richwiz1

Stock thermostat calls for 195 degrees lot of people run 180 degree good for summer or winter. As far as fan problem check make sure previous owner did not rig them to run that way both should only run when a/c is on or extremly hot. The thermostatic fan should kick on around 238 degrees.

Both? I only see one.

Is there one in front of the rad I can't see? How exactly do I check to see if they're rigged (I assume they are)?

I changed the thermostat, coolant temp sensor, and rad cap this weekend. The temp gauge still sits at the first hash mark between 100 and 220 so I guess that's 190 or so.

Richwiz1 · 10-05-2009, 05:45 PM

I made the fatal mistake I assumed u had dual fans and when assume something u know what that does? Makes *** out of u and me LOL to check if they rigged u will have to trace the wires. Check your relay coul be stuck on.

Saabster · 10-05-2009, 06:27 PM

It's ok, could you tell me where the relay switch is supposed to be?

Richwiz1 · 10-05-2009, 08:17 PM

Mines on drivers side close the master cylinder not sure on yours one should be for fuel pump one for fan just unplug one fan quits you got the right one some of the other threads on here may tell u how to check it unless they have wired straight to battery. If its aleady running to cool for emissions why do u want it to run cooler? 50/50 should be good. could be temp sensor or fan switch.

Richwiz1 · 10-05-2009, 08:18 PM

Mines on drivers side close the master cylinder not sure on yours one should be for fuel pump one for fan just unplug one fan quits you got the right one some of the other on here tell u how to check it unless they have wired straight to battery. If its aleady running to cool for emissions why do u want it to run cooler? 50/50 should be good.