Engine Overheating

1999 Chevy Lumina

the needle keeps going to 240 does that mean that it is over heating? If so why is it overheating?

Yes it sounds like it is overheating. First off I need to know when it happenes. Is it while driving or sitting still or all the time. Have you checked the coolant yet?

It happens when I drive. I just put new coolant into it. After that is when it started to act up.

It sounds like you have a stuck thermostst. I would change the t-stat and rad cap and make sure the cooling fan comes on.

Thank you.

I was driving my car an the car went to hot. i noticed the hot light came on. I than looked at the temperature an it was all the way over. I got the car to a safe place an pulled over. I let the car cool off for an hour, i than checked the coolant an the engine oil. The coolant was low the engine oil was fine. I noticed when i lifted the hood it was some kind of brown oil that was on the hood an it leaked a little around the inside of the car. I let the car run an it went back to overheating. An i noticed a leak from the radiator it was clear. Its my first car the old owner let it sit after not needing it anymore an than decided to sell it. Do you think you could tell me what they problem may be.

As far as overheating, does the radiator fan run? In not, check the fan system. Some makes and models, if you turn on the ac, the fan/s will run. Again on some makes and models if you unplug the coolant temp sensor, the fan may run. Just trying to find out if fan will run?

If the radiator leaks, you need to fix that. I recommend a new radiator, if that is the problem? Yes, you can use radiator stop leak or take the radiator to a radiator shop. As far as I know, if radiator tanks are plastic and the leak is in the tank, radiator shop can't fix it. They may be able to order new radiator?

Check for applicable trouble codes, see if it leads anywhere? To check codes yourself, at the least, you need an obd2 reader. Some of the national brand autostores will check codes for free. Check the coolant temp sensor

Have you ever replaced the thermostat? On a cool engine can you check for coolant flow through the radiator? If possible with radiator cap off, cool engine, start vehicle, watch the coolant, if the coolant level starts rising really fast, you may have a head gasket problem?

I can only make suggestions on what to che3ck, you have to do the testing.