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Discussion Starter #1
I'm definately not even close to being a car expert so forgive me if my questions sound dumb sometimes. What is the normal range for the coolant temperature. I have a 1985 coupe and it just seems to me it's running hot, especially when I have to sit in traffic. I watch the temperature creep up a little to fast for my taste. My gauge says the temp is running between 195 (on the highway) and about 230 degrees (when idling). Too hot, right? It certainly smells hot when I stop!

Thanks in advance for any and all advice you can give this girl! :thumbsup:
 

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Your temps are in normal range. The L98's came from the factory with 195* t-stats. Seems you are right on the money there. Your 85 came with one main fan and an auxillary fan was an option. The main fan is ECM controled to come on at 227*. If you have the aux fan (found under the front bumper infront of the radiator and is controled by a switch in the right head between #6 and #8 plugs), it will come on at 238*. GM designed these cars to run a little hotter than most for emissions purposes.

I really don't like to see my engine temp above 200*, so I had a chip programmed for the fan to come on at 200* and off at 190*. Note that I run a 180* t-stat and my highway temps stay around 175-180*. In traffic, with the programmed chip, my temps don't get above 200*

To sum it up, it sounds like the temps are in range with the way GM designed it. Oh, GM also says to shut the engine off if the temps get to 260*.
 

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I hated my C4 running that hot. I ended up wiring my fans to come on everytime the car was started. I also installed a 180 degree thermostat. After that the car never got over 195 even in traffic.
 

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Discussion Starter #4
Thanks!

Wow, it does run hot! Thanks for the good info, I think for my own piece of mind I'll have my husband do what you guys did and fix the fan to come on at a lower temperature. I really appreciate the input, at least now I won't worry when I'm stuck in traffic :D
 

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ECT/Dash Temp mismatch

On my 95 the engine coolant temperature (ECT) reads the correct 227 degrees and the fans turn on. The ECT is also confirmed by my OBD tester. At about 227 ECT the engine temp on the analog dash temperature reads up to 240-260 degrees. Just letting it idle in the driveway, the ECT hits 227 degrees and the engine temperature guage shows like 257 degrees and the fans turns on and the temp starts to drop. Is something wrong with the car? Thanks in advance for the help.
 

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Yep, mine runs on the open road at 200 and up to 230 with any kind of a load on the engine (ie hills etc.) I thought is was running too hot until I started reading some of the posts on this forum. Now I'm a little more comfortable seeing the gauge in the three quarter range.
 

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your coolant temp range is normal,(not ideal, but normal for a stock 1985 corvette)


engine oil needs to reach and stay at about 215F-240f to lube and clean correctly and burn off moisture

trans fluid I try to keep under 160F,surely below 180F ,

Ideally I try to keep engine coolant in the engine in the 190F-200F range but don,t get overly worried below 230F. BTW I run a 190F t-stat, temp ranges should be kept within these ranges or the wear and emmissions won,t give you the long engine and trans life and low emmission levels you expect .

, drop the coolant temps lower and you may gain a few hp but the wear tends to get worse as the fluids can,t opperate correctly, drop the oil temp below 211 F and acids can form in the oil (bad for bearings)



 

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I feel your pain! I would have to say most of us corvette owners want our cars to run at the same temp as the rest of the cars we own. For me that would be 200 to 210 degrees. My 1988 corvette has a 180 degree stat a hypertech chip that turns my primary on at 175 degrees and I have wired a bypass switch on my aux fan so I can turn it on any time I want. My car still ran 190 degrees yesterday with the air on and the out side temp at 86 degrees. That was running down the road 60 mph. But in town it will still climb up to 215 degrees. I have removed and cleaned my radiator and condenser. Everything is working correctly. Give your car the test! pull it in to the garage. With the door open start your car and turn on your AC and see if the cooling fans can keep up with the heat. I did this test and my car with the 180 stat and both fans running could not I stopped the test when the temp gauge got up to 220 degrees. I am going to Vette Fest at Mid America in september and I am going to ask Gordon Killebrew if there is a way to improve my cooling fans:lookinup:
 

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Discussion Starter #9
Thanks guys!

I really appreciate all your help! I bought a thermostat that is supposed to kick the fan on at around 160 degrees but have yet to get my husband to install it;) . Hopefully that will help things a bit.
 

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curious question about cleaning the radiator fins - ? can i use a "coil cleaner spray" like they have for cleaning out the air conditioner coils on the radiator? or do you think that it would do more harm than good?

I bet if the radiator was cleaned well it would be able to transfer more heat to the air, with out having to fight thru the crud on the outside of it.

how else would you go about cleaning the radiator "mesh" if using a coil cleaner is a bad idea? I wouldnt want to hurt it.
 

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curious question about cleaning the radiator fins - ? can i use a "coil cleaner spray" like they have for cleaning out the air conditioner coils on the radiator? or do you think that it would do more harm than good?

I bet if the radiator was cleaned well it would be able to transfer more heat to the air, with out having to fight thru the crud on the outside of it.

how else would you go about cleaning the radiator "mesh" if using a coil cleaner is a bad idea? I wouldnt want to hurt it.
I blew mine out with compressed air and then sprayed it with a pressure washer. But only after it was removed from the car.
 

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a garden hose some degreaser and some time taken to inspect and clean the fins is usually all thats necessary, its much easier to access on a lift or jack stands but certainly not totally impossiable to do in the driveway on a couple ramps.


http://www.raceramps.com/store/shopexd.asp?id=62&bc=no
 

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I really appreciate all your help! I bought a thermostat that is supposed to kick the fan on at around 160 degrees but have yet to get my husband to install it;) . Hopefully that will help things a bit.
The thermostat does not control the fans. It simply controls the flow of coolant between the engine and the radiator. The fans are controlled by the computer. You can have the computer (I think it's the ECM) reprogrammed or install a manual switch that allows you to turn the fans on and off.
 

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Discussion Starter #14
Oh thanks

Ok so now I'm a bit confused, is it a good or bad thing to lower your temps. I've read some places where people install the switch to kick the fan in sooner and then others who just let it run at the higher temps. I don't want to damage anything one way or the other and I suppose if that is the temp it is meant to run at I should leave well enough alone?? I'm a girl and new to this engine talk so forgive me if the questions sound a bit stupid:huh: I guess the digital dash kind of freaks me out because you can see the temps creeping up degree by degree and all my other vehicles the gauge just sits there :lookinup:
 

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in an ideal world the coolant temp would stay in the 190F-200F range, install a 180F-or-190F t-stat and have the fans reprogramed to come on at about 185F-200F and youll see a marked stabilization of the coolant temp IF everythings functioning CORRECTLY

heres the fan control kits

185F

http://store.summitracing.com/partdetail.asp?part=SUM-890015

200F

http://store.summitracing.com/partdetail.asp?autofilter=1&part=PRF-30102&N=700+115&autoview=sku

personally I sellected the 190F T-stat 185F fan control , but IM seriously thinking of getting the 200F fan control simply because with my external trans cooler the engine oil temp seldom gets over 220F and it takes 215F to burn off all moisture in the oil
 

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in an ideal world the coolant temp would stay in the 190F-200F range, install a 180F-or-190F t-stat and have the fans reprogramed to come on at about 185F-200F and youll see a marked stabilization of the coolant temp IF everythings functioning CORRECTLY

heres the fan control kits

185F

http://store.summitracing.com/partdetail.asp?part=SUM-890015

200F

http://store.summitracing.com/partdetail.asp?autofilter=1&part=PRF-30102&N=700+115&autoview=sku

personally I sellected the 190F T-stat 185F fan control , but IM seriously thinking of getting the 200F fan control simply because with my external trans cooler the engine oil temp seldom gets over 220F and it takes 215F to burn off all moisture in the oil
Why do almost every car I have ever owned and many that I have worked on in the past have not and do not run this hot? I respect your opinion and your knowlage.:lookinup:
 

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Why do almost every car I have ever owned and many that I have worked on in the past have not and do not run this hot? I respect your opinion and your knowlage.:lookinup:
corvettes are not your average car, theres usually a good bit more horsepower,displacement and other perfoprmance mods that build heat, and alot less room under the hood for air flow thru that radiator,due to the low hood line, bottom air flow entry, ETC.
the compact space and higher performance builds heat, this is NOT necessarily bad if its controlled and stable, higher heat can be used to more effectively build power and lower emmissions AS LONG AS its controlled and predictable, and well within the lubracation and octane limits the engine can use effectively
 

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Ok so now I'm a bit confused, is it a good or bad thing to lower your temps. I've read some places where people install the switch to kick the fan in sooner and then others who just let it run at the higher temps. I don't want to damage anything one way or the other and I suppose if that is the temp it is meant to run at I should leave well enough alone?? I'm a girl and new to this engine talk so forgive me if the questions sound a bit stupid:huh: I guess the digital dash kind of freaks me out because you can see the temps creeping up degree by degree and all my other vehicles the gauge just sits there :lookinup:
Back in the old days (sigh) engines ran at about 190* or cooler. The newer engines are disigned to operate at higher temps, primarily for emissions reasons. In the October issue of Corvette Enthusiast there is a great article about the cooling system. On page 68 is a table that gives the fan operating parameters for the various C4s. For the 85 - 89, the fan is programmed to come on at 226*. If the car was equiped with RPO B4P (radiator boost fan) it came on at 235*.

Keep in mind also that analog gauges are not necessarily linear. By that I mean that the middle hash mark is not the average of the two end points. Usually it is closer to the optimum level. For example, on my 93, which has both an analog and a digital temp gauge, the analog gauge has a low reading of 100* and a high of 260* but the mid point is not 180*, it's actually closer to 210*. On my wife's Lincoln LS the temp gauge (analog) is almost always pegged at the center mark. When I checked the temp with a hand held digital thermometer the reading was 220*.

One final thing, there are no stupid questions only stupid answers.
 

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Discussion Starter #19
Oil temp question

My oil temp hardly ever rises above 198 and if it does it is after I have been driving for a while. Is this something I should be concerned about? I drive my Vette daily and we change the oil every 3000 miles:huh:
 

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My oil temp hardly ever rises above 198 and if it does it is after I have been driving for a while. Is this something I should be concerned about? I drive my Vette daily and we change the oil every 3000 miles:huh:
Your oil temp should be higher, about 225, to help burn off any moisture that gets into it. It's possible the gauge is off but I'm not sure how to check it.
 
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