100% correct. Claiming the engine must run over 195*F is complete BS because GM would have put in a higher temperature thermostat if that was actually true. My car might be driven for months without the temperature getting over 200*F. It only has 170k miles on it now...

 

@chevyvette98! - if you have an automatic then 100% do an ECS mail order tune. Even if you don't, it's a cheap way to accomplish what you want and they do a few things that improve performance.

 

The same that yours is when it runs that cool, which it does, often.

 

Driving back and forth to work, 20 minute drive, the bulk oil temperature as measured by the gauge never goes over 190*F. Even in hot weather it just barely gets there as I reach my destination. Which goes against all those who claim the oil must or will reach >212*F every drive....

 

195ish if your car is in good mechanical condition.

 

I didn't think of what's best, GM did according to you and that's how they delivered it. And yes, oil temps will track very close to coolant at low RPM.

 

Excellent. I'm glad we agree that 195 is the correct operating temp on the highway as delivered by GM and that it doesn't hurt a thing.

 

Why are you filling a question thread with this crap?

 

Its generally a good idea to make decisions based on 50 year old advice, especially from people who were likely mostly clueless at the time.

 

The OEM fan settings are;

Fan #1 on at 226F, off at 219F
Fan #2 on at 235F, off at 227F

Now if for what ever reason you believe that these are too high by say 10F or 20F, then by all mean lower them. But keep in mind that the fans are turned off at speeds of 35 MPH or higher. So for city driving the lower settings means that the fans will be running a higher percentage of time. This means two additional things as noted above, increased wear on the fan motors and for the 1997-02 M6 and 1997-01 A4 cars with the 110 Amp alternator and the '01-02 A4 car with the 120 Amp alternator, higher loading on those alternators. The '03-04 A4 & M6 cars had the 145 Amp alternator and this increase loading maybe less of an issue.

You are most likely going to also need;
- a larger capacity radiator that will typically hold 1 gallon more coolant to help reject the extra heat in the system.
- lower range than stock (which is rated to begins to open at 186-187F and fully open by 195F) thermostat, but keep in mind that the 160 degree aftermarket unit is NOT designed for street use, so you are basically stuck with an alterative of a 180F unit (and do NOT even think about drilling holes in the unit either!)
- a thermostatically controlled oil cooler setup, if your engine is designed for 5w-30 oil, then you would want a 180F thermostat in the adapter block for the oil cooler

Once you have done all this, then MAYBE the engine coolant temps will stay below 200F most all of the time. But realize that is a pretty big investment for a street driven cruiser. Now if you also live in an extremely warm climate, if you do autocross and/or HPDE track events or run at the drag stripe occasional, then these changes will pay extra dividends. As always, YMMV.

 

Well the replacing the radiator is in the plan but mostly because there is aged evidence of a very tiny leak, and I want to get out in front of it before it gets any bigger, as all small leaks do.

I didn't realize once a thermostat reaches its opening temp, that it did not open all the way but may take a few extra degrees to open all the way. So for that reason I will replace the stock thermostat and install the 180 to see how that runs. If the 160 is not offered by Chevy, then I'm inclined to not put it in.

So maybe with lowering the temp at which the fans kick on at and the 180 thermostat and the replacement radiator, I might get to the driving temps I want. I am in the Chicago area so occasionally we will get into the the high 90's or low 100's, but not often. Generally in the summer we will have a string of 80's and 90's for a few weeks in a row or maybe even a month.

Any suggestions where I should purchase a replacement 3 row radiator with aluminum side tanks, Automatic.?

 

Suggestion, comments and debate will abound on the subject of which HD radiator is best, too expensive or that are imported junk. There are top quality (and expensive) units like DeWitts, Ron Davis and TracSpec among others and then there are more budget minded units like ECP that most have had good luck with. Not sure which year you have, but since its an automatic, beware that early in the 2001 model year the factory changed the connection style on the transmission cooler lines at the radiator (at least once and possible twice through 2004), so make sure you order the correct unit. Also if you are looking for a simplified engine oil cooler setup (but not necessarily the absolute best for hard core track use) some radiator manufacturer's also offer an optional EOC built into the driver's side radiator end cap that can make things somewhat easier as far as that installation is concerned.

 

JHrinsin, it's a 98. And DeWitt's is what was on my mind. But the radiator alone is in the $850ish area. I was also considering the fan kit they offer at $460ish. The factory fans run at 1850 rpm and the Dewitt's run at 3200rpm. I know that's alot of $ for a non tracked car, and so I guess I would consider a less costly option if I could be assured it would be good quality, construction and reliability.

I have heard of ECP, but never heard of Ron Davis or TracSpec. And I would prefer American made.

 

Ive had a DeWitts for 18 years. Absolutely no issues. You don't need the fan kit. The stock C5 fans move enough air to keep my 600+hp LS7 under 200°-205° in Florida weather. On the Mustang dyno, in 3 pulls the coolant never exceeded 180°!! Consider I also have a 25% UD balancer. Spend your money on something else. My .02.

 

I put a single Spal fan on mine, but I did so because the stock fan shroud is restrictive to the point it adversely affects cooling at speed. Back then I was tracking the car. I noticed it ran a few degrees cooler just on the street after the swap, so I know it made a difference there. As has been pointed out though, the stock fans push plenty of air to keep the motor cool. This is another example of things progressing the right way in the last 50 years.

 

i have a 160 stat. first fan comes on at 164, second at 170. works well.

 

romandian, did you have the fans programed to turn on at those temp's ? And is so, how was that done?

And are you saying the motor runs temps of 160's -170's all the time?

 

Yes u have to go to a tuner or a scan tool. Turn on 160 low fan turn on high fan 170. Compared to stock which is in the 200's. i think.

 

temp is 160 +/- 1° all the time, even during "spirited" driving with 15 psi boost except when idling, then the fans come on and keep temps below 170°. all componens are original and 25 years old. this is on the c5. on the 2008 zo6 (3" rad) im having weird cooling problems with the 160 stat that miraculously disapper at higher speeds. (i figure the bottom feeder is a much better system.)

oh, i have efilife.

 

Just to clarify, you're claiming that besides a 160 tstat and fan reprogramming, your otherwise stock, original cooling system maintains a 160 degree coolant temp under any driving conditions? I find that extremely difficult to believe unless ambient temps never reach more than 30 degrees where you live. I ran a 160 tstat for about a year and even on the coolest winter days (40ish degrees), my coolant would reach "normal" operating temperatures just cruising on the freeway. I swapped it back out for a stock tstat the next time I had my blower off and the only real difference is that it reaches normal operating temp faster, which is more desirable anyway.