My engine is overheating?

Yes, the thermostat can be replaced without removing the intake manifold. 1. Partially drain the cooling system. 2. Remove the air cleaner and duct. 3. Follow the upper radiator hose to the engine to locate the thermostat housing cover. The thermostat is located at the end of the lower intake manifold on the driver's side of the engine compartment. You may also want to disconnect the coolant hoses connections between the throttle body and thermostat bypass pipe to make it easier to fit a socket wrench in there. 4. Loosen the hose clamp, then detach the hose and the coolant reservoir tank line form the thermostat housing cover. 5. Remove the thermostat housing cover and the thermostat. (Note: Remember which end is supposed to face out when you do this.)

6. Install thermostat with the new seal. 7. Reconnect hoses and refill cooling system. When choosing the coolant for your car, GM recommends the orange-colored "DEX-COOL" silicate-free coolant and replacing it every 100,000 miles or 5 years. You can also use the green-colored ethylene glycol anti-freeze, replacing it every 30,000 miles or 24 months. Before deciding which coolant to use, keep in mind DEX-COOL has been known to eat away at gaskets.

I have changed the water pump, thermostat and it still loses anti-freeze and overheats when driven on the freeway. The motor is a 3.1

where is it losing it? any leaks noticeable on ground? is it going out exhaust pipe? maybe bad head gasket or intake gasket? you can get cooling system pressure tested and also test coolant for exhaust gases.

Hello again,
Ok ive kept filling it allthough there was hardly any if at all coolant missing and when hot i smelled nothing under the hood or in the car , another weird thing happened though i was driving it yesterday on my way to town the temperature gauge was doing its funky thing again, i could feel cold air flowing so i knew it was going up, but this time it whent all the way up till the overheat light came on, i pulled off the highway and stopped the car immediately and popped the hood, when i opened it i was expecting a lot of heat coming towards me but this wasnt the case, i could touch the engine it was warm but not hot it was warm as to be expected from a 15 minute drive, i squeezed the radiatore hose and again it was warm but not burning hot as to be expected from an overheated engine.
I brought it in to my mechanic shop and he looked and try to figure out wat the problem was. He couldnt tell me he said it might be the head gasket still but he said then the engine would feel a lot hotter.... i dont even know what it could be its a mystery to me, and any help is apreciated a lot. Thanks in advance !!

the cooling system on this car has to be bled.you can't just add coolant and go.you must bleed out the air in the system.signs of air/air pockets would be erratic temp gauge,heat that may come and go. also you should have a leakdown test performed to verify that there is not a head gaket issue. and these cars are infamous for intake leaks.first try to bleed the system and let us know what happens.

Engine Cooling problem 6 cyl Front Wheel Drive Automatic 145020 miles

after replacing water pump still over heating

Hello,

It sounds like you have a stuck thermostat or a blown head gasket, here are a couple of guides to help you get the problem fixed.

https://www.2carpros.com/articles/head-gasket-blown-test

and

https://www.2carpros.com/articles/replace-thermostat

and

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Please run some tests and get back to us so we can continue helping you.

Best, Ken

I have changed the radiator, the water pump and thermostat. After changing all parts I let car run for over 30 minutes with no issues. As I drive off in it the needle starts to rise and overheats. The coolant shot out of the overflow hose. I was having the same problem before changing these parts the only difference was it was leaking coolant before. No leaks now but it gets hot very quick to the point where the antifreeze/water is boiling in the coolant tank til it shoots out.

Hello, unfortunately that's the signs of a bad head gasket. Pressure is being pushed into the coolant system from a cylinder(s) and causing the over flow, overheating symptoms.

Let the car cool down over night and pop the radiator cap off and start the car. If you have bubbles coming out if the radiator, the head gasket is bad. That's a quick easy check. Do not open the radiator if it's hot.

Engine Cooling problem
2003 Chevy Malibu Front Wheel Drive Automatic

Today I added a green color of antifreeze and now my car is overheating and the needle on the gauge is going up. I now have heard that the antifreeze for my car is supposed to be orange and that they should not be mixed. How do I correct/fix this now that they are mixed?

HI there,

If the engine was well down on coolant in the first place you will need to have a cooling system pressure test done to find any external leaks, then flush the coolant out by removing the radiator hoses, removing the thermostat and disconnecting the heater hoses, flush the system with fresh water and replace hoses & thermostat and re fill with correct coolant, bleed system of air.

mark (mhpautos)

had new water pump put in, since then car started overheating and loosing coolant. also, it is blowing cold air. car never overheated prior to new water pump.

Sounds like the pump was either installed incorrectly, a connection is loose or broken or you had a different failure. I would take it back to the place that installed the pump. Prior to that look for the area the coolant is leaking from. It should not be hard to find. Blowing cold air could mean the heater core is plugged or the blend door has fail but it is more likely that the leak allowed air into the system and it will not purge out because it is still leaking.

Just installed heads, gaskets, thermostat, water pump, and coolant tank. Have bled coolant system numerous times and still running around 240 degrees. Upper and lower radiator hoses get hot but the hose from radiator to coolant tank stays maybe lukewarm. Can rev engine and see coolant being pulled down. Fans also work properly.

Hi,

Have you checked the coolant temperature sensor? It may be sending a faulty reading. There could be excessive resistance in the wiring, connector, or even the sensor. Do you have a digital thermometer? It seems you have done a ton of work on this. Also, although the engine seems to be running hot, is it running properly? For example, smooth idle, normal power and so on?

Joe

The only code I have is for the EGR. It runs perfect for maybe 1 minute then a rough idle unless you hold the throttle around 1,000 to 1,200 rpm's. I connected a Blue Point scanner and on the live stream it showed the temperature was around 233 to 240. Would a bad temperature sensor still show the temperature I was receiving on the reader? Or is that the sensor it goes by?

Yes, the sensor works based on resistance. The amount of resistance drops as the engine heats up. The voltage to the computer changes based on the resistance change. If the sensor is failing and indicates low resistance, the temperature will be wrong.

That signal will also show on the scan tool.

I will get a new one and try in the morning. I will let you know how it goes. Thank you

Hi,

If you have a digital thermometer, you can get a reading from the radiator. I hate to have you get a sensor and it not be the issue.

I do have a question. When the engine starts running rough, do you ever notice black smoke from the exhaust? I ask because if it is dumping fuel, it can cause the engine to run hotter than normal. That could be a fuel pressure regulator or injector issue.

Interestingly, without a diagnostic code that is relevant, I start thinking of all possible causes. Even a partially plugged catalytic converter can cause it to run hot. That's why I was asking if it had normal power and so on.

Joe

It does not smoke at all. The engine will idle down to around 500 rpm's and shutter a little. But as soon as the rpm's get back around 700 or 800 it smooths out. I can let it run to what should be around regular temperature and hold my hand on the radiator and hoses. It is warm but nothing scolding hot. I can also lay my hand on the plenum and it's just warm. That's with the temperature gauge inside being 3/4 or more of the way up. But the hose from the coolant tank to the radiator seems cold so does the coolant in the tank. When you rev the engine you can see the coolant pull down a little but the coolant and hose does not seem to change temperature with the rest of the system.

To be honest, everything you described sounds normal. Have you tried using a digital thermometer to see if the gauge is accurate?

Joe

I recently had a problem when I drove the car 2003 malibuand came home and parked it all the antifreeze would come poring out, brought to mechanic and he changed the thermostat. Brought the car home and it did it again , brought back to the mechanic and said the system need to be bled AND ANITI FREEZE CHANGED. Just drove it again today and it leaked but not as much when I opened the hood I noticed that the overflow bottle has a hose attached that is attached to nothing and that seems were today's leak came from is that hose supposed to be just loose and not attached to anything.. Need advise please....

Is there a fitting on the radiator where that hose might go? Call the person that worked on it, if you can't find where the hose fits.

Just to add, without being able to look at it, I can't think of anything else.

2003 Chevy Malibu had it flushed and changed ECT sensor. Now white smoke coming from tail pipe and rough idling.

overheated three times and had to limp it home. It appears to do the overheating when you reach your destination and shut the car off would overflow through the overflow tank no water leaking anywhere else. The last time it overheated the engine shut off as I was driving.

White smoke from exhaust is without a doubt headgasket failure. Will need heads pulled and replaced DO NOT continue driving bering damage will occure.