OK, a silly question. :o In my teens, I used to work on cars a lot. Now I don't. That past knowledge might be a good thing, or it might be hurting.

Basic question, then some follow up questions please?

Please what is the normal engine operating temp on a 95 Vette with an LT 1 engine?

I was driving home from the Atlanta airport to home via 85 in Friday afternoon rush hour traffic. At the 85/285 junction is was real slow moving traffic the temp rose, finally at 227 degrees I cut in the heater to bled the heat, got off quickly and rested the car a few minutes at a local resturant parking lot.

I got home ok, but still the temp bothers me

When the car moves the heat w/o heater will hold about 197 to 205 at 90 degree outside temp. At a light it shoots up quickly, after a few red lights it can go to 230. I cut in the heater and it goes down to 213 quickly. I have never let it go over 230 so I do not know how much higher it would go.

So does anyone know the metrics on the temps?

Also are the above temps a problem? I admit, I am a Vette rookie. My knowledge is based on old car technology (60's and early 70's) and a butt "feel" for how I think a car is running. At 230 the Vette began to seem hot. In traffic I cannot tell if the fan cuts in. I dont hear it nor feel it. At 230, by a "seat of the pants" manner the car felt too hot. Ok, so maybe I was a ***** for cutting in the fan. I just got this girl and I am going ot take care of her.

In looking under the hood, I noticed the angles of the air cleaner assembly and radiator. Perhaps stuff gets in there that clogs air flow. I am careful in traffic to provide enough space from cars in front of me to avoid their exhast which is both hot and low in O2 content (again, based on old technology thinking). My car can't run good if it sucks in hot bad air, again old thinking.

Ok, so, please how hot is too hot on the enging temp? Any suggestions.

Thanks folks.:o

 

My 93 runs between 196 and 200 while in motion. When stopped the temp will climb quickly to 230+. The fan should come on around that temp, I think it's 230 or 235. Just open the hood , let it idle and see if the fan comes on around 230. Only one of the two will work, the second should come on when the A/C is running. Keep this link, it has some great infor on vettes.
https://www.corvetteforum.com/techti....php?TopicID=2

 

Hi, I guess we might be from the same era....when our sb's ran at 180 -190, any higher & we'd be having a fit!

I just got my C4 awhile back, 12/04. It took me along time to get used to the temps. Go to the ZR1NetRegistry site and click on "maintenance". Then click on "how to" , in tha section you will find some things that might help answer some Q's....at the botton of that section is a link that will lead you back to a Q & A from this fourm on C4's, and there is another wealth of info there....sorry I don't do P/C stuff well so I don't know how to post links...I don't get this stuff too well.:o

Any way to give a summary, check out the item on building a screen for the air intake under the front splitter and read the item by Lars about r&r'ing the radiator shroud and radiator to clean out the stuff we suck up, also there is a thing about checking the fan relays to make sure they come on when they are supposed to come on, and then there are write ups on making manual fan switches so you call them when you want or let them come on via the ECM programing.

As an aside, I did the clean out the radiator & screen thing & the 180 T-stat and it does help a bit....my car had no milage so I didn't have much stuff in the rad & I put the screen on asa I got the car so it saved me some cleaning. Oh, I use my A/C switch to call both fans when I get caught in B to B stuff....yea I know it sounds strange but when the A/C is called on line the secondary fan and the primary fan both run & they do pull down the temps....because my system is free of junk I think...but it works till I get moving again. The air flow is from the bottom, under the bumper, to the rad and C4's suck up all the garbage off of the road.


Good luck with your new toy!

Tom

 

Typical operating temps for the later C4's should be in the 190 to 205 range and if the ambient air temps are high, you might see 210 or so.

Modern motors are designed to run hot for emissions purposes so higher temps are the norm. Going above that consistenly points to some issues in the cooling syystem and should be addressed.

The ECM controls the operation of both fans from input from the cooling temp sensor at the front of the water pump. The secondary fan should come on around 228 and remain on until temps drop back to the 190's. Tuning on the A/C forces the secondary fan to run regardless of the coolant temp. This is an easy way to check that the secondary fan is operating peroperly.

Because the C4 is a "bottom-breather", it's easy to get the A/C condensor and radiator clogged with dirt, debris, small animals, slow pedestrians, Honda's or whatever. You can easily clean the radiator with a garden hose and stream of water from the engine side. Air pressure works too.

I'm not a fan of manual switches or lower temp t-stats. The system ws designed to handle hot climates and if everything is working right, you should not have problems.

I would suspect enough junk in the radiator to keep adequate airflow up; could be something as simple as a plastic bag that got sucked up oin the street. You can also check for the usual cooling system problems like a lower hose that is weak and collapsing, a sticky t-stat or even low coolant level. If the secondary fan does not run, it could be a bad fan relay, or temp sensor.

 

I put a 160 t'stat on mine and changed on/off times. Used to run 205 or so road and up to 240 + in traffic,
now it runs 177 road and 194 in traffic. But your temps are normal for the 95 vette and others.

 

On 95 the fans work together & have 2 speeds...Hi & Lo. "Lo' speed at approx 228* & "Hi" at 238*. If you get concerned turn the a/c on & fans will be on "Hi" Mine runs the same temps as yours & has for 11 years. Nothing to worry about.

 

The temps you are seeing are normal, but I don't like 'em. I installed a 160*F thermostat in my LT1, and reprogrammed my ECM to kick the cooling fans on/off at 190/180 primary, 195/185 secondary. The car now runs MUCH cooler under nearly all conditions, and I'm much more relaxed about it now, with the additional headroom in the cooling system.

Two cautionary notes:

1. The thermostat used in the LT1/LT4 engines is NOT the same as the thermostat used in the standard Small Block Chevy engine. The LT1/LT4 'stat is a dual-function unit that regulates flow through the radiator, and bypass/recirculation flow during warm-up. When it opens to allow flow through the radiator, it also shuts off bypass/recirculation flow. If you swap your thermostat, make damned sure the one you get is for the LT1 engine. If it doesn't look like the one you remove, don't put it in there, or the car will overheat.

2. If you reprogram your fan on/off settings, make sure that you set them sufficiently high that they won't run all the time. With a 160*F thermostat, I'd recommend you set the primary fan on/off at 190*F/180*F, and the secondary fan on/off at 195*F/185*F.

GM does not make a 160*F thermostat for the LT1 engine. You can buy one made by Hypertech at a decent speed shop.

Be well,

SJW

 

My suggestion is that your temps are where they should be. Make sure the fans are cutting as suggested above and note at what temp. Anything at 240* and climbing....I would be worried. You can turn on the A/C to activate the secondary fan.