Fans not kicking on until very hot

So I've gotten Hilda home and started sorting things out...  Had new mufflers and a crossover pipe installed to keep her quiet.  The better and balanced backpressure seemed to smooth out a lot of the stumble she had from idle, even.

Next is the AC, taking her in tomorrow and hoping to keep it under a grand but the clutch is gone, like sheared off, and there is a hole in the condenser.

What really worries me, though is the fans.  She runs cool as a cucumber at highway speed and gets up to around halfway on the gauge in light traffic, but in stop and go she gets up to the very last white hash mark before the red zone.  Gotta love that sickly sweet smell of coolant struggling to do its job.  Cant be good for the old girl to run that hot.

Popped the hood today and verified that the twin electric fans arent coming on until that last hash mark.  Is there an easy way to tell them "Hey, lazy asses, get to work around 160 or so!"?  Going to need them working earlier especially if I can get the AC going.

When you use the AC, one comes on automatically.

Tom

silverfox103 wrote:

When you use the AC, one comes on automatically.

Tom

Hmm, should test out if that works, even with my AC's current state.

MG Davis wrote:

silverfox103 wrote:

When you use the AC, one comes on automatically.

Tom

Hmm, should test out if that works, even with my AC's current state.

Well you'll have to trust us on that one,..

it works off the a/c pressure,.

No pressure,. No fan,..

Doh, hopefully then it'll fix itself when I get the ac done this weekend.

::bump::

Any ideas on the fan? Is it a setting that I can have flashed to the ECU, a different sensor, switch, etc?

Hey Mike, there is a thread here about this very issue. Anyone with the reprogramming tool can do this for you. I think the fans do not kick in till 229 and 234 degrees. 180 makes more sense to a lot of owners too. Hilda has a 150 degree thermostat instead of 180 btw. [You must be registered and logged in to see this link.]

Yeah, the sticky was the first thing I read, but it doesnt get into how to change the settings. Great tip on the programming tool, though. Guess I need to find somebody who has one in the area.

Bert Slater wrote:

Hey Mike, there is a thread here about this very issue. Anyone with the reprogramming tool can do this for you. I think the fans do not kick in till 229 and 234 degrees. 180 makes more sense to a lot of owners too. Hilda has a 150 degree thermostat instead of 180 btw. [You must be registered and logged in to see this link.]

The dealer can, and possibly a speed shop?

it'll run hotter with a lower opening temp thermostat and the fans not programmed for the lower opening temp,.

The lower opening temp stat is simply open all the time,. not letting the hot water soak in the radiator long enough to reduce its temp,..it's a bad idea to use the wrong T stat,.unless the ecm is programmed for it,.

The thermostat is opening and closing constantly,.the motor takes in as much cool water as it needs,. then the stat closes partially,.

It's been such a myth, that motors make more power when they are cooler,. they need to be tuned for cooler temps,..

your fuel mileage is optimal with the engine at 190 deg's,..

I run a 195 stat in the orange car,. and it takes a lot longer to get to the hot zone in traffic with the air off,.

but,you do what you want,. you're gonna anyway,.

phantom 309 wrote:

It's been such a myth, that motors make more power when they are cooler,. they need to be tuned for cooler temps,..

your fuel mileage is optimal with the engine at 190 deg's,..

I run a 195 stat in the orange car,. and it takes a lot longer to get to the hot zone in traffic with the air off,.

but,you do what you want,. you're gonna anyway,.

That's kinda the point here, to find out what to do, but you'll assume what you want anyway.

Car came to me with a low t-stat.  Even if it had a 195 t-stat, it would be wide open when I'm in traffic just like a 150 degree because there's no airflow.  I'm not looking for power, I'm looking to not overheat because Florida.  Running at 230 degrees every time traffic goes to hell can not be good for her.

MG Davis wrote:

.  Even if it had a 195 t-stat, it would be wide open when I'm in traffic just like a 150 degree because there's no airflow.

If you are stuck in traffic and concerned about water temps,. you can unplug the temp sensor in the front of the water pump,.

It will set a cel,. but both fans will come on within a few seconds, and run continuously,.

when you plug the sensor back in ,. the cel will go out,.

Hmmm. so if a switch were wired in to the sensor circuit it would turn both fans on?

or if you have an OBD1 car, jumping the terminals on the ALDL will set diagnostic mode on the ECM and kick on both fans.

Well that worked out nicely...

Got the entire AC system rebuilt.  Was not cheap, but its murder here in Florida without AC.  On the drive home, she never spiked at all even in stop and go.  Seems having pressure in the AC system and running it was enough to kick a fan on like its supposed to.

Lesson learned:  Dont try to run one of these things without working AC.