I replaced my thermostat to a 160 as well as my fan switch. And it ran great for a few days then... It started to get hot. Not quite overheating but still to hot. I checked my fan and fluids and they were good. So should I get a better radiator or better fans or both? And if so which ones? Any help would be great thanks

 

A few things you can do...

1) 160 stat may be too low for your car if it's stock. ECM is looking for temp ranges higher, and a lower stat may affect mileage or something. I'm not real sure what the TBI ECM looks for and how it changes fuel and/or timing - but I have always heard and read here that typically a 160 is too low, and that a 180 should be the lowest used.

2) "Normal" op temp for your car should be 190 - 230. These cars ere factory designed to run hot (as perceived by all of us old schoolers that think temps should be lower). Hotter temps mean better fuel economy with all this emissions crap. So as long as your under 240, you're not overheating (unless your guage is off).

3) You have a single fan, correct? The fans on these were a terrible design (maybe part of the running hotter=better emissions design). This was one of the first GM cars designed without shrouding around the fan, and the fan is placed over an inch away from the radiator. This means the fan is sucking alot of air around the fan instead of through the radiator.

You can get aluminum roofing flashing at Lowes/Home Depot i 14in x 10ft rolls for about $11 and make a shroud around the fan to help pull air through the rad instead of around the fan. I simply cut to fit the round fan, riveted inplace on the fan, reinstalled the fan cutting the straight edge on each side to get wedged into the radiator edge. That helped my temps some.

4) Water Wetter, or your brand of choice, added to the radiator helps reduce temps. O'Reilly's has a brand on sale this week buy one get one about $8. I add a bottle every year and it seems to reduce temps by about 10-15 degrees (never seen the 20+ difference they advertise, but it helps and worth the $8)

5) TBI system does not interact with the control of the fan like the TPI system does, so the ECM has no control over when fan comes on. I always hated the stock fan switch in the head design - they never work well.

I opted for an aftermarket fan controller from Flex-a-lite, about $100. It's fully adjustable, easy to wire, has provisions for dual fans, A/C, and inside manual on/off switches. No need to even remove the factory in-head switch to install one of these - it probes the radiator between the fins. I've had mine 4 years now, and it's been absolutely great, always works, always where I set it, can adjust cooler for summer and warmer for winter. Mine actually turns fan on at 65% first, then after 2 minutes if temps aren't reducing it kicks in at 100% speed - this reduces initial amp load on electrical system. It really is a great product and the best $100 I've thrown at the car yet!

Good Luck!

 

ok thank you, those are some good tips. well my car is not stoc. it came witha regular 305 and i swapped it out with a 350 with alot of preformance parts and i want it to run at 160 because i noticed the colder it is the more preformance it puts out.

 

If you try the aluminum fan shrouding, after you get a good fit, cut some rubber vacuum hose down the side, and glue on the edges - after I did mine I had a terrible rattling sound from the aluminum vibrating on the radiator

 

http://www.carnut.com/ramblin/_cool3.html

Putting an 160 degree will not help with performance.

 

I'll agree - the car will 'seem' to run better at cooler temps - never had a car that didn't. And the article linked above verifies - you DO get slightly better performance with a 160 stat over a 180 stat. But, that article also tells the long-term tale of running cooler stats, ie more engine wear.

I was having a heating issue a few weeks ago - I swapped in a 160 just to see. It really didn't help me enough to justify it. Getting my fan on temp adjusted better, adding water wetter, and most importantly getting better timing adjustments helped me out the most. I was never overheating, was just hot (220). 220 is normal for a stock car, but I'm not stock anymore, and 220 is a bit high for my old school setup. I'm back to a 180 now and everything is just as good if not better.

If nothing else, swap back to the 180 after the summer heat dies back - 160 is definitely no good in the cooler months of the year.

 

Keep in mind that just because you have/using a 160 stat, doesn't mean your running a 160!

I'm using a 160 stat and a Hypertech #4026 fan switch(On at 177*/Off at 166*) this combo keeps my temps around the LOW 180's.

And I do like the idea of a self-made fan shroud, or could go with aftermarket!

 

Installing a 160 deg thermosat without changing the prom (chip) in the ECM is your problem. The ECM is seaching for the correct parameters and can't find them, so close & open loop and fan control functions are screwed up so the cooling problems. Nothing is simple on these first gen computer controlled cars.

 

Great read guys thanks for the info. I always thought my car was going to blow up from it running so hot.