Topic: Running hot, blower issues?
in Forum: C3 Cooling and Heating Systems
Already a Member?
Click Here to Login
Not yet a Member?
Click Here to Register for Free!
78 runs extremely hot. Was told the blower may not be working?
How can I check this myself, and I am not seeing any blower?
On a side note, heat and ac do not work as well.
Thank you in advance.
SPONSOR AD:: (Our Sponsors help support C3VR)
Runs hot as in engine water temp hot or just hot inside?
202010261047r.jpg)
DanT
Both actually, engine gets super hot within minutes
And the inside gets hot as well. Attempted to use Ac
Pro product then learned I need r12 instead since it's a 78
Going to get some from eBay to at least help with the inside
Several things to check for engine overheat, thermostat primarily, may be sticking/stuck closed. What does temp gauge read?
C3's are notorious for being hot inside passenger compartment. Need good insulation under carpet, make sure all vents are closing, that will let a ton of hot air in. And of course be sure A/C is working. Have an A/C shop check out system.
DanT
thermostat recently changed, ac dose not work, thinking blower as well ( but not clue where it is )
temp is just over 200 immediately, and every fluid leaks, trans, oils and gas from bowl.
Project car indeed, but that's why I am here.
|UPDATED|7/25/2016 6:48:52 PM (AZT)|/UPDATED|
Sorry, but I still don't understand your problem. Could you take a little more time and post a detailed description. Maybe have the wife or one of your kids proofread your post. I don't mean to be mean, but your posts are pretty disjointed. This place can help you with your cooling problem, we just need more info. 
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
The engine running hot, and the HVAC blower not working are two separate issues.....one has nothing to do with the other.
First off, you need to determine if the engine is actually running that hot. The gauges in these cars are not the most accurate to start with, and the temp senders are notoriously flaky. IF the engine is actually getting that hot that quickly, you have a problem with coolant circulation, whether it is the thermostat(which you state is new), a water pump problem, or a clogged radiator. First try to determine if the gauge is correct. Use an infrared thermometer and measure the temp on the intake manifold where the thermostat is, and the input/output hoses on the radiator. Let's find out for sure what the actual engine temp is first, and we can go from there on how to diagnose what is causing it.
As far as the blower motor, it is located on the passenger side, under the hood, waaaaay up inside the fender on the firewall. If it is not blowing at all, there are several things that can keep it from working. However...if you have already put 134 freon in the system, at a bare minimum you will need to discharge it, flush the system, evacuate, then put 134 friendly oil in the system, and finish with a new charge of 134.
The blower motor has a resistor set-up in the A/C plenum under the hood that controls the low/low-med/med-high speeds. The high speed(only) is run thru a relay, also mounted on the A/C plenum. You also have the switch in the console, and a fuse to power the whole shebang. Start by testing the fuses.
First off, you need to determine if the engine is actually running that hot. The gauges in these cars are not the most accurate to start with, and the temp senders are notoriously flaky. IF the engine is actually getting that hot that quickly, you have a problem with coolant circulation, whether it is the thermostat(which you state is new), a water pump problem, or a clogged radiator. First try to determine if the gauge is correct. Use an infrared thermometer and measure the temp on the intake manifold where the thermostat is, and the input/output hoses on the radiator. Let's find out for sure what the actual engine temp is first, and we can go from there on how to diagnose what is causing it.
As far as the blower motor, it is located on the passenger side, under the hood, waaaaay up inside the fender on the firewall. If it is not blowing at all, there are several things that can keep it from working. However...if you have already put 134 freon in the system, at a bare minimum you will need to discharge it, flush the system, evacuate, then put 134 friendly oil in the system, and finish with a new charge of 134.
The blower motor has a resistor set-up in the A/C plenum under the hood that controls the low/low-med/med-high speeds. The high speed(only) is run thru a relay, also mounted on the A/C plenum. You also have the switch in the console, and a fuse to power the whole shebang. Start by testing the fuses.
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Not sure why you would not understand it?
Car runs very hot, the engine gets up to 200 and interior as well due to engine
Running hot.
Ac dose not work at all, I'm told the blower dose not work
And I don't know how to test or fix the blower or even
What it looks like.
Thermostat was changed. Car leaks all fluids , just don't know what to do next
in Forum: C3 Cooling and Heating Systems
SPONSOR AD: (Our Sponsors help support C3VR)