New Owner w/ question

[copper94]

Greetings....
new owner, have a 94 copper metalic LT1 coupe for about 8 weeks. This is probably the first of many questions.....

Does the car usually run very hot when in stop and go traffic or sitting for a while. I notice that mine will go just right to the point where it could overheat, at least on the guages and then once I move along it drops down.....is this normal. I do not seem to have any heat either, not sure if this is related, a bad thermostat, stuck valve? Any one share the same experiences...

sorry, was more then one question.......

 

[c4cruiser]

Welcome to the CAC!! You'll get lots of help here just by asking. Great color on your 94!! Only 116 Copper Metallic cars were built!
You can check out the Tech Center and go to the Model Center to get some neat stats for your car: http://www.corvetteactioncenter.com/specs/1994/94prod.html

What temps are you seeing in traffic? Typical temps in slow city traffic can run between 195 to 210 and even higher in hot weather. C4's are "bottom breathers" in that all of the cooling air come in from below and behind the front license plate. It's very common for this area to get full of dirt or debris like paper, leaves, the neighbor's cat or small Honda's.

Look up under there and pull any chunks off the front of the A/C condensor then take a garden hose and flush the radiator with a soft stream of water from the back side. There is room to stick a nozzle in past the cooling fans on the radiator shroud.

Lack of heat from the heater and overheating while stopped may mean not enough coolant in the system. Is the "Low Coolant" light on the DIC on?? With the engine cold, remove the pressure cap from the expansion tank and check the coolant level. The correct level should be just below the rim of the opening so fill as necessary. Use a 50-50 mix of coolant and water. Start the motor and let it run until the temp gets to where the thermostat opens (195 for a stock 'stat). Increase engine speed to about 1100RPM and see if the level in the tank drops. If it does, add more coolant and then replace the cap. Also add coolant to the overflow bottle in the right front corner to bwtween the cold and hot marks.

Another possibility is an air bubble or pocket in the system. The system is bled by opening a bleed valve on the thermostat housing. It's a brass slotted screw head and can be seen from the passenger side. Open the valve to see if a steady stream of coolant flows out (NOTE: don't let too much coolant out as it may fall down onto the OptiSpark distributor and cause it to fail.).

Do the electric fans come on?? The primary fan should come on when coolant temp reaches about 218 or so and will run till the temp goes back down to about 195-197. The secondary fan comes on at around 228, Also, turning the A/C on will force the secondary fan to run so that's an easy check to make for operation of that fan. Both fans are powered by relays and are controlled by the ECM. Sometimes a relay will fail and not allow the fan to run.

 

[Hib Halverson]

Greetings....
new owner, have a 94 copper metalic LT1 coupe for about 8 weeks. This is probably the first of many questions.....

Does the car usually run very hot when in stop and go traffic or sitting for a while. I notice that mine will go just right to the point where it could overheat, at least on the guages and then once I move along it drops down.....is this normal. I do not seem to have any heat either, not sure if this is related, a bad thermostat, stuck valve? Any one share the same experiences...

sorry, was more then one question.......

First, let me congratulate you on a very unique purchase, 94 Copper Metallics are quite rare. If it's one where the paint on all panels matches reasonably well, it's even more rare. IMO 94 Copper Met. is one of the best damn looking colors of the late C4 era.

If you're basing your assessment of coolant temp on what the analog temp gauge says, don't. The analogs in C4s are horribly inaccurate. Use the gauges button above the DIC to page though the digital displays until you see coolant temp. If the cal in the ECM is stock, you may see 225-230 deg in heavy traffic before the fans come on and cool it down. You also can kick the HVAC on, which commands fans-on regardless of temp.

Look up into the cooing air intake and see if there's junk and debris trapped on the radiator. If there is, clean it out. If you find a lot of stuff there you may need to get the top of the cooling stack off and remove any debris you find between the radiator and the HVAC condenser. Lastly, you want to check for proper fan operation using the instructions in the service manual.

 

[Vette_Newb]

Look up into the cooing air intake and see if there's junk and debris trapped on the radiator. If there is, clean it out. If you find a lot of stuff there you may need to get the top of the cooling stack off and remove any debris you find between the radiator and the HVAC condenser. Lastly, you want to check for proper fan operation using the instructions in the service manual.

Wal Mart sacks (the blue plastic ones) are very notorious! Welcome and congrats on the Vette!

 

[Randy Eads]

Copper, you'll find that these discussions on "running hot" are going to finally lead to the question "Is a hot running lt1 a bad thang?" and scores have been written on that.

You have a programmable '94 as I have a '93 that takes a chip ... but the end result is the same ... keeping the mouse from getting hot.... and that can be solved with some tweaking (fan switches, thermostat change, reprogramming, etc) if it is something you decide to do.

I did and never looked back! There is alot of information accessable through searches on this site! Weigh everythings and make the changes if your comfortable with them! ... Good luck .... and congrats on your purchase!

 

[copper94]

Thanks for the help.....still no heat

I think I kinda like this place.....really great to get the notes back, I kinda stumbled into finding out about how few of these there were only after I bought it.
Anyway....coolant level is good, did open the valve to let it breath too. Now seems that when I idle the car for about 20-30 minutes it is at about 215. Driveing is now about 198-202. This is reading the read out on the dash not from the analog guages. So I think I am doing better in that respect. But still do not seem to get any heat when the climate control is on. The fans seem to work when they are supposed to and the system is blowing air from the floor vents, but not warm air??

thanks!!

 

[c4cruiser]

Have you tried varying the temperature setting on the display? Select either the "Auto" button or one of the two buttons that show the airflow going down or down and out the dash vents.

Does the defroster pump out hot air??

 

[copper94]

No heat & another question.......

OK....c4cruiser, thanks for the things to try but still no luck with the heat. After letting the car warm up and drive, the defroster is also blowing cold air, and in either auto or "just floor" vents or "dash & floor" vents selected do the same. Is there a valve somewhere that could be stuck or needs to be checked? There is no fluid leaking anywhere.

Also....when the car is cold, and started up for the first time that day....it is very hard to get the car in gear....reverse is especially tough. Once driven, even for 20 minutes...the car is fine the rest of the day. Any thought....

 

[Randy Eads]

Low fluid level (air in system) causes tough shifting.

Check the level on your hyd. clutch ... its under the computer module left firewall ... three nuts and the module lifts up .... I think alot of people overlook that item during regular maintenance .... I replaced my nuts (ouch!) with wing-nuts which makes servicing and inspection easier.

 

[Vette_Newb]

Sounds like either someone has bypassed the heater core (leak possibly) or the core is stopped up.

Check the heater hoses going into the firewall on the passenger side of the engin compartment. If they are looped or connected together it is bypassed. If they aren't looped, feel the hoses (be careful they could be very hot) while the motor is running and warm, if they are hot then it could be clogged, if one is hot and the other is cold then it most likely is clogged. If they are both warm, it is something under the dash, there is a controller that opens and closes the door to allow the fan to blow air over the core. You can remove the passenger side lower dash panel and manually open the heater door carefully and see if it allows warm air into the vent system.