Checking back in with everyone here to provide my experience and what solved this issue for me. This is not professional advice, I am not a certified mechanic, just a guy fixing his own car - 2002 model.
TL;DR: Pull the actuator, screw down the pin. Reinstall. Fixed, fan goes fast all the time. No more
overheating.
Let me start by saying that the actuator can be removed from under the hood, but it is a very tight space.
After much trial and error, and almost stripping my actuator, this is what I can advise so that you can save the many headaches I went through. It took my at least a week of fighting with this thing, but I can now do the job in less than half an hour.
- Let the engine cool down completely.
- Unbolt the hydraulic fan fluid reservoir. It is bolted in with two different sized bolts, one 8mm and one 10mm. A standard ratchet and sockets will work fine for this step.
- Disconnect the back hose from the reservoir. Fluid will come out, try to catch it in a container to avoid spillage.
- Use something to block the opening to the top of the exposed hose and to the bottom of the reservoir in order to avoid dust and dirt from getting in the lines. Personally, I used paper shop towels.
- Move the reservoir up and towards the front off the vehicle, push the hose back and out off the way. Now you have a path to the actuator.
- Disconnect the the electrical plug connected to the actuator and tuck the wire out of the way.
- Use a 18" 120 tooth power torque ratchet (like this) with a T40 3/8 drive TORX bit attached to it to get the actuator to break free. THIS IS CRITICAL as the space is very tight, you will not have enough room to use a standard ratchet. You may be able to get one on there if you fight enough, but you will not have enough leverage to break it free. If you try to use the drill set up mentioned in the next step, before using the breaker bar, you may strip out the actuator.
- Use a drill connected to a long hex extension, connected to a right angle adapter (like this), fitted with a hex shank T40 TORX bit to unscrew the actuator the rest of the way. Do not use a flex adapter as they will likely bind up.
- Remove the actuator from the vehicle.
- On the actuator you will see an adjustment pin/screw that can be removed or adjusted with a flat head screw driver, tighten this down by adjusting the screw clockwise. It should be noted that removing this pin, as recommended in above posts, does absolutely nothing. I tried this entire process and ran the vehicle with the pin removed and my fan spun at ~300-400 RPM at all times, which resulted in overheating just like before.
- Reinstall the actuator going in reverse order of the above steps, be sure not to over-tighten the actuator with the power torque ratchet.
- Refill the hydraulic fan fluid reservoir to the designating lines using new ATF fluid.
- Start the car and measure your fan speed with a laser tachometer to see if the adjustment has made a difference. It should now be running somewhere in the range of 800-1600 RPM. It is not overly loud but there is a noticeable visual and audible difference when inspecting under the hood. Your car will no longer overheat, AC will be blowing cold - at least this is my experience and I've been driving it for a days, hundreds of miles now, in the Texas heat.
This is where the actuator is. You can see it with the plug still connected and a
T40 bit connected to it:
View attachment 29412
This is the actuator pulled and the tools I used. Note that I have a metal pipe enclosing the hex extension and most of the right angle attachment, I used this to help with grip.
View attachment 29413
Here is another picture of the drill set up:
View attachment 29414
