I took my car to my mechanics to get an oil leak and a radiator hole fixed, and when I get it back, I'm leaking antifreeze! I check the coolant levels, and (when the engine was cold) it was about 4" above the engine hot level! I was like "WTF!" He changed my 180 degree thermostat I had in there! So I took it back, and he said the fan wasn't coming on untill it hit 250, and I got it back. He said on GM cars, the fan should start at 235!, I think its because with my 180 degree thermostat, it never went beyond 220. Is this guy f*cking with me?

 

If you run a lower thermostat- you need to lower your fan activation range as well. I run a 180* Thermostat and the fans come on at 195* and off at 175*. I also run a custom 4-core radiator to keep things that low. Otherwise you will get too much fluxuation and cause premature engine wear. from the temp changes.

 

A good2.8 - how did you adjust the activation temperatures? An aftermarket cooling fan switch with sensor, reprogamming the ECM???

just curious cuz I hate that constant fluxuation when in traffic.

 

Yes, prom chip is recalibrated.

 

Then fan does come on at about 235* from the factory. Too hot for me. I put a fan switch under my light switch. when it gets above 200* I hit the switch and back down to 190*.

 

Mine kicks on at 200*-220*.

 

How do all you guys know when it is kicking on and off, are you going by the gauge on the dash and interpolating or are you reading the computer.

I am curious about my dash gauge and/or sensor because when I read the gauge (which only has like 3 #'s) and after I convert to farenheit, the temperature where it likes to run on the highway I calculate at 167 - 170 yet I have a 195 stat! Then it will go up just past the 105 in traffic which equates to as much as 230!

I have a new rad, highflow 195 stat and heater core. DO you guys know of any way to test the accuracy or do I need to hook a computer up to the ECM to read what it reads??

 

In my answer, I had the chance to have a "scope" hooked up to the ALDL system. I heard fan kick on at 200*-220*.
My car still has idiot lights, not the ready to install guage package (it will be SOON!)

 

Had it hook to a Diacom diagnostic scanner to verify prom specs.

 

I installed a set of gauges...lights come on when it's too late

 

Well, me and my friend changed the thermostat back to a 180, and we let it run for about 15 minutes. When I checked it, it was at redline!I don't think the engine can get THAT hot THAT fast!Oh, and by the way....the fan wasnt coming on AT ALL! Is the sender bad? What do you guys think?

 

I've had the same problm for months now. I never hear my fan kick on. I'm even running the jet Stage II performance chip, hoping my fan kicks on earlier and it doesn't. I was told to replace the coolant temp sensor but sice i'm running the chip, i heard it won't make a difference.

 

If car has operational AC, check fan motor that way.
Put back in the proper temp regulator.
If need so, get new fan motor, it's an easy swap!

 

Couple of things -

Stock, fan comes on at 222º F. Shuts off at (I believe) 183?

If you want to tell if your fan works at all, just park the car, engine off, and ground the diagnostic terminal in the ALDL connector. (paper clip or speaker wire works really well) then set your key to 'run' (DO NOT START THE CAR.)

When in diagnostic mode, the fan should immediately come on, and stay on.

If it doesn't, look for a power/ground problem to the fan.

 

Excellent call!
It's the upper row of the two level pin connection. the end two connections on the right.
Use a thick paperclip as the jumper wire works perfect!

 

Aftermarket fan switch/relay here. Works really good, except when the fuse blows

 

I feel for ya all.

With my true ram air and home made air dam [ I just used aluminum insted of floopy rubber], I have a hard time just reaching proper engine temp. Let alone ever warm enough to even consider letting a fan run.


This is as warm as it will get.


Of corse if I sat still for ever it would get hot. I have the fan on a togle but have not needed it.

Matt

 

That's about where mine runs, (above pic) since I put in my 160 degree thermostat. Fan is also on a toggle, generally don't need it. Recently I've read that running your motor TOO COLD can cause premature wear. I thought a cooler stat would prolong engine life--maybe I should switch to 180. Also, my car seems like it is using a little oil, which it never used to do, and I'm wondering if the above mentioned "fuel in the oil" contamination could be the cause.

My car definitely runs way better now, but I also live in Southern California, where it's pretty warm. Getting a bit cooler now, so just to be on the safe side I'm switching back to 180 degrees. I still think the stock settings are way too high though, IMHO.

 

A colder engine can build more carbon. It can/could hurt things but would take lots of time. [It may help by building compression.]

Me and the car both like the cooler temps. its run strong n hard all the time. When before I got my temps down. It got sluggish when the temps got near 200.

I have the stock thermo though.

The biggest temp drops were when I removed all my AC stuff.
[everything]
Made an air dam from aluminum and the true cold air ram air helps too.

 

Put in the 180 tonight, runs great! Engine feels more flexible, and revs are deeper and rumblier. Now I can see that the motor was "tight" with the 160, but I had never tried the 180 before, now I'm sold. Engine is definitely happier a little warmer, maybe also because the weather is now cooler. Also, checked the oil, and it's fine. Think I checked my oil on an uneven surface, leading me to think there was some missing.

Now my temp stays at 180, and my manual fanswitch is there if I'm stuck in a drive thru. Even when stopped though, my temps don't rise much.

Used a Prestone Gen II 180 degree stat. Usually use Stant. The Prestone Stat seems to open a bit late, so I either have air in my system, or the stat isn't very good. Changed my temp sensor, and now it shows the stat opening sooner, but still not until 220*. Flushing the system this weekend, and my mixture is about 70/30, so we'll see if going to 50/50 coolant and water helps.

I must say that owning my second F-body is the one of the best experiences of my life.

 

Yes engines do ware faster when operated cool.
I have read this in books copy righted as far back as the early 1970's.
It is well known they ware out faster.
I don't have any thing near a clear answer why.
They will build up more carbon when run cold, oil gets more moisture in it from combustion.
Yea when they get to hot they don't like to respond and get slugish.
The only time I stall my little toyota is when it gets real hot, it acts weak when real hot.
I think our fuel injected v6's like to run 180, they don't like to hit 220'F.

 

Okay, after a few days with the 180* thermostat, I definitely notice a bit less power, and the motor feels a bit "softer" when you hit the gas. Same power maybe, but the motor doesn't feel as perky as with the 160* Runs just as good though, and maybe a bit better on the highway.

Yep, I've read all over the place that running the motor cooler can cause wear, mainly because parts don't expand as much as they were designed to, so rings, bearings, etc. can wear faster. The big one is the piston not swelling enough for the rings to seal properly, so gas can contaminate the oil, and the pistons can slop around a bit more. That's what I've read, in several articles. Also, combustion isn't as efficient. So the 160 is recommended more for racing motors. I know, some guys say there is no problem with them, but the majority seems to agree that the motor will wear faster over time.

So why less power? I'm assuming it's because my motor is now 20 degrees hotter, and so my underhood air is much hotter as well, along with my intake manifold. The way a colder stat makes power, is by cooling the intake charge, and allowing more aggressive timing, which I haven't messed with.

As someone mentioned earlier, the way around this is Cold Air Induction. There is also a 170* Thermostat available from AC Delco, through GM, according to one article, which gives the "best balance between performance, economy and wear." I'm going to look into that, and some way of getting cold air to my open element.