Quick question, I have a "89", with a 195 degree themostat, will it hurt to change to a 160 degree, don't like engine reaching 220 degrees with the a/c on.

 

Please run a search on this, there have been many threads on this. Hopefully this one sneaks by and baby jesus doesn't cry.

 

Think about what a thermostat does, how it works, and it's effect on your operating temp. This subject has been argued to death, countless times. Do a search. If you read every thread and follow every link, you will be busy for months.

RACE ON!!!

 

my opinion is on my website

or run a search and read the 1019878379842793827 posts on the subject

 

I won't help, it could hurt.

 

What's a themostat?


NO.

 

Are you guys sure you don't want to say it ONE MORE TIME (LOL)

 

Like the "bubbas" said, this has been a HOT (pardon the pun) issue with many here for a long time. I'm fairly certain that if you run a search on this, you'll get your questioned answered many times over.

Ultimately, you'll discover that just a 160 thermostat will not do it alone as the fans need to be reprogrammed to come on sooner. That is where the magic is. You'll also find that 220 is not an uncommon temp for the engine to run at and not considered an overheat temp. My 94 did this too only it got a tad hotter (235). I flushed the system, cleaned the radiator like a crazy man and put in a 160 with the fans reprogrammed and the temperatures I now run at in the summer heat with the A/C going strong are around 200.

So do the search and beware that this subject is a sore spot for a lot of strong personalities here.

Good luck!

Billy

 

 

 

Sorry to bring up such a sore subject, this is my first vette, not too familar with all the in and outs of the car, just that 220 degrees sounds way too warm.

 

Read and pay attention. Before asking about, possibly over discussed subjects, do a search. Get to know your car. 220° is not unreasonable for a C4. Think about what a thermostat does. How could it possible lower your operating temp? As a perfect example, look at the post above, by wilsonbh. He did a lot of good maintenance and dropped his operating temps from 235° to 200°. However as you can see, the 160° thermostat has no effect on that. All that thermostat has done is lengthen the time it takes his engine to warm up (a bad thing). Hopefully, his fan(s) aren't running constantly, too.

RACE ON!!!

 

220° is below the stock turn on for the fan so no that is not to hot. You can run the car cooler if you want to, read the other back threads on this same topic for tons of information. The seach button is up on top, search on thermostat here in c4 tech.

 

However, you must use correct spellings for the search function to work properly.

 

No it won't hurt. No, it won't help that condition either. My car had a 160* in it when I got it. Sitting in traffic on a hot day, the temp would climb till the aux fan would come on. Changed to a 180*. The only difference is the heater actually works in the winter before I've driven 25 miles. No difference at all sitting in traffic on a warm day. That's the way my '87 behaves anyway. If I change again, it will be to a 195* as designed. jmo

 

I only found 65.

http://forums.corvetteforum.com/sear...archid=5450077

 

As noted, 220 is below the temperature for fan operation (idle to about 45 mph). With the a/c off, the ECM doesn't ground the main fan relay until the Coolant Temp Sensor indicates 226 degrees. At cruise however, it should be around the thermostat regardless of a/c operation. If it's climbing or staying at 220 once your on the highway, then the a/c system is either plugged up, overcharged or the air flow is restricted.

Idle fan control, with the compressor engaged, is controlled by a switch that receives a reference voltage from the ECM. That switch opens at a pressure of 230 psi and the reference voltage rises at the ECM to it's full potential. The ECM uses this signal to ground the main fan relay. The air flow across the condensor cools the charge (reduces it's pressure) and when it drops to 190 psi, the switch contacts close. The reference voltage then drops to 0 and the ECM removes ground from the Relay. Since the "on" signal is merely and open circuit, disconnecting the harness from the switch should turn on the fan. That switch is on the high pressure line from the condensor to the evaporator next to the high pressure switch. The one that turns on the fan when disconnected is the switch you want (the one that doesn't allow the compressor to engage when disconnected is the high pressure switch). If it doesn't turn on the fan when disconnected, the signal wire is open or the ECM is bad. To see if it's opening and closing within it's parameters, you'll have to hook up a Manifold Gage Set.

A/c is designed to maintain an average high side pressure of about 200 psi when the outside air temp is 70 degrees or better. This provides the best cooling with minimal cycling of the compressor. Keep the pressure too low, and the compressor will cycle on and off causing a rise in vent temps (similar to an undercharged condition).

You need the thermostat because a/c builds pressure (temperature) rather quickly and without the fans, it could spiral out of control and blow a hole in the hood. The thermostat simply allows it to reach an operating temperature quickly, in spite of the fact that the fan has been running since shortly after you started it. Assuming the a/c system is right, it's going to run cooler at idle with the a/c on and if it doesn't, there's some sort of problem. I'd make sure there isn't a problem first - you'll gain nothing with a cooler thermostat - and every car built in the last years operates the same way (and pretty much at the same temps); if you don't believe it, hook up a scanner to your Camry.

 

dont worry bill, we all have to learn and start some where mate.
btw, i run a 180 degree thermostat but thats the lowest i would go.
even 195 degree stat would be ok to use as well.
im using a emp/modified robert shaw thermo stat that supposed to be balanced /modified and be more accuarate so they reackon.
they retail for around $10-$13 dollars.
good luck any way on what you decide to do and keep up the learning.
regards
shae

 

Changing with a 180 degree tomorrow, will let you know how it goes!!!!!

 

Why the change? What are you hoping to achieve?

RACE ON!!!