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cooling fan issue or not?

idrivejunk

Active member
I began to notice several weeks ago that with the A/C off, my stock 99 GTP's engine temperature as shown on the gauge would climb to 210 when idling.

I figured thats one of the fan motors gone bad. Both fans have replacement motors already, neither is more than a couple years old.

So today when it climbed to more like 220, I went under the hood for a look.

Both fans come on with the A/C. Otherwise, no fan at all.

Whats wrong? Thanks in advance.
 


Do you have a scan tool or anything of the sort? the ECT (Engine Coolant Temperature) sensor on these cars is actually 2 sensors in 1. One sensor for the gauge and one for the PCM. We want to verify what the PCM side of the sensor is doing, so if you have a scan tool hook it up and see if it'll tell you what your current temperature is. If you don't have a scan tool, do you have the automatic climate control by chance? Believe it or not, the climate control interfaces with the PCM to see what the current temperatures are.
 
Wolfing down pancakes now. Will try the unplug thing in a few minutes. I do have a CEN-TECH scan tool. Back shortly...
 
Oh and yes its the dual zone automatic (the older kind with display), Boo.

ECT sensor is the one on the radiator tank, right?
 
No it's on the driver side of the engine, on the under side of the LIM. Look under the thermostat.
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Damn I feel noob-esque, thanks for the image. I put my Snap-On shirt on, maybe that will help intimidate the car. Here I go...
 
19mm or 3\4" IIRC, and a wobble will be your friend. Might be a good idea to drain the radiator a bit before you take the sensor out, it'll drain the LIM of coolant.
 
Man, yeah that thing is in a bad spot to even unplug while running. But thats the trouble and thanks again brethren. I am amazed how well the thing cools even with no fan.

Watched it (on the tool) climb from under 200 to about 212. During that time, the sensor threw readings in the 300s a couple times. No fans. Unplug sensor, fans galore.

I just loathe doing the coolant fill procedure. I like to have two heat / cool cycles before hitting the road so this will be an all afternoon project. Luckily I am able to park in my garage and use a fan to direct a/c from the kitchen at it. That helps speed it up. I needed an excuse to use Grape today anyway, now I just have to get past being lazy. Much obliged, gents.
 
Yep, this has been partially broken for some time. Sure was tough to find a tool that would do the job in my ghetto cardboard tool box.

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Well, we're post-install at this point. How to test? The plastic part wiggled a tiny amount in the metal part but it seemed secure. I wish I knew what parts manufacturer we're supposed to trust nowadays. I'll stick with nobody. The engineering of that whole area eludes me, man. "Here, lets point this wire directly at the exhaust flange!". It wasn't exactly cake getting to it.

The fix is holding. Can't say I know what normal temp is on a GTP but I took it for a spin and it stayed below 210. I'll keep an eye on it. Didn't lose more than a couple ounces of coolant, just made sure I had the new sensor sealer-ed and ready in the same hand before removing the old stump.
 
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