ClearCoat

Hi,
Everytime I drive my '99 torch red corvette, the coolant temperature gets hot very fast. Even after a few minutes of driving, the coolant temperature will reach 160 degrees. After a 30 minute drive, it will push 220 degrees.

Also, the oil pressure can reach 44 psi even after a few minutes on the road.

Should I be alarmed, or is this normal? I don't race my vette, and I don't even have a single mod on my car.

Will flushing the coolant help? Please help me out if you can.

-Clearcoat

dougbfresh

Does not look like a real problem, are your cooling fan(s) coming on OK? Where do you live and do you sit in a lot of traffic?

j84buick

30 minute "drive" meaning > 35 mph most of the time? I think that's way too high. 30 minutes of sitting in traffic/city driving with outside temp @ 85? 220 is not too high.

In normal driving I rarely get above say 192. Even when it's 80+ outside.

Never hurts to flush if it's due.

ClearCoat

Hi,
I live in Dallas, Texas, and I have been driving with no traffic.

I get the 220 degrees for the coolant temperatue when driving during outside temperatures between 40 and 70 degrees.

Today, it was 32 degrees, and my coolant temp managed to reached between 160 - 190 degrees after about 5 - 10 minutes of driving.


-Clearcoat

Pumba

What temperature would you like to have the coolant stabilize at?

GM Race Engineering states that the LS engine family makes its best power when the coolant temperature is between 180 and 189 degrees. On the C6R race Corvettes, the drivers are instructed to turn the engine off it the coolant temperature reaches 190 degrees.

fdxpilot

Check the front of the radiator/ AC condensor assembly for something blocking airflow. The C5 is a bottom breather and can suck up an amazing amount of stuff. I have pulled out paper and plastic bags, as well as leaves and other garbage. Anything like that will cut down the amount of cooling air through your radiator.

However, the min temperature on your system, if it is stock will be around 190 deg F, as that is the thermostat GM puts in it. If you have any blockage, the system will get to that temp quicker, which sounds like your problem. The Stat controls the min temperature of your system. Even a low temp thermostat won't help if your system has air or coolant flow problems.

dgrant3830

One usual cause of higher coolant temps, not that your's is that high, but usually is debris in the condensor coils plugging up the airflow. Sometimes plastic bags and other junk and most of the time, a gazzillion small rocks in the vanes. They can be washed out or blown out from the reverse direction with either an air-wand or water wand of some sort. Other than that, as already stated, check the fans for normal operation. Typcially they turn on at low-speed around 225 degrees I think and at something like 235 degrees, they go to high-speed. Both fans run when they are running. To verify their operation, simply turn on the Hvac. They will run unless the outside air temp gets down to somewhere around 42 to 38 degrees at which time, they will shut off.

Evil-Twin

A C5 is a bottom feeder... Clean your AC condensor fins which sit directly in front of your radiator, which also needs to be cleaned, they sit piggy back with an inch and a half in between the two .. Your temps are far from abnormal.. but indicate there is a restriction in the heat transfer rate. I clean my cond/radiator once a year and pull a year's debris of bugs, leaves, dirt, paper and sand, which accumulate in the cooling vanes. Every year I remove a half cup of this debris.

Bill Dearborn

Getting to 160 in 5 to 10 minutes isn't unusual. If you are getting to 220 while driving over 35 mph continously in 32 degree weather then you have a cooling system problem. Either the air flow through the radiator is restricted or your thermostat is stuck. With a stock thermostat and 32 degree ambient temp at highway speeds the coolant should be in the 190 to 195 range.

Bill

RoccoC5

Early last year I started to see temps of 220+ in 75 degree weather while on the freeway. I cleaned the condenser and radiator, flushed coolant and replaced the thermostat, and have been comfortable at 192-194 ever since.

As for oil pressure, I generally see 32-35 psi at idle, with oil temp around 205 degrees, IIRC.

hayman

Did your air dam fall off? I went over a speed bump, slowly, one time and my center air dam fell off. Temps were noticeable higher until I replaced it.

runamuk

While checking for debris in the condensor and radiator as well as making sure your air dam is in place are good ideas and will probably offer an improvement for your cooling, it's important to remember that if your car is stock and the fans have not been reprogrammed that the factory setting will not let the first cooling fan come on until the coolant reaches 225 degrees.

And while the C6R engines are optimized to run between 180 and 190 degrees it's extremely important to remember that your engine is not a C6R and shares little to no parts of that race engine.

TEXHAWK0

It is possible that your thermostat is not opening completely.
It does not seem unusual for the engine to get to 160 deg. fairly quickly, but once it gets to 195 deg. the thermostat should open and the temperature should be relatively constant with a low ambient temperature.

High oil pressure is not due to high engine temperature. In fact, the oil pressure is higher when the oil is cold and the pressure should come down as it heats up. At a given temperature, the oil pressure should increase with RPM, not coolant temperature.

lucky131969

I don't think they would win too many races that way.....

ClearCoat

Hi Everyone,
Thanks for you help so far with my engine cooling issues. I read in consumer reports that the '99 vette gets a full black circle for engine cooling so I am cautious.

The air dam in my car is fine. Is there somewhere on the internet or a book that can show me how to clean the debris in the condersor coils, condensor fins, and radiator in my C5?

I am also getting a "low coolant" warning while driving, but the coolant level in the reservoir seems to be at the proper level. I am going to have a radiator shop flush the coolant this weekend.

thanks again
-Neil

David426

Our cars (especially lowered cars) are huge vacum cleaners.. Its unbelievable what may be in between rhe 2 condensor/radiator fins. You will have to pull the fan shroud off.. The part that says " caution fan" and the air bridge.. Use compressed air or a hose/sprayer.. Spray up and down from back side of fins.. Be real carefull not to bend the fins.. Too much pressure will easily bend them Try an experiment... Make a fist and bang on the front bumper with the back of your fist... Make sure the garage floor is clean... Hit the bumper 4-5 times then look at the floor under the radiator... I bet your clean floor is not clean anymore

travis742

I think you have air in the system,

lucky131969

Hopefully the OP will respond to this 2 year old thread.....