Overheating 1999 Malibu

If your 1998 Cutlass is overheating and the heater is blowing out cold air, and you are also noticing that coolant is leaking out, there are a few possible causes. Here are some things to check:

Check for a coolant leak: Start by checking the engine and radiator for any visible signs of a coolant leak. It's possible that a hose or other part of the cooling system may be damaged or loose, causing coolant to leak out.

Check the radiator: If the radiator is not working properly, it can cause the engine to overheat. Check to make sure the radiator is not clogged or damaged.

Check the water pump: The water pump circulates the coolant through the engine. If it's not working properly, coolant may not be flowing through the system correctly, causing the engine to overheat.

Check the cooling fan: The cooling fan helps to keep the engine cool by pulling air through the radiator. If it's not working properly, the engine may overheat.

Check the thermostat: Even though you recently replaced the thermostat, it's possible that it's not working correctly. A faulty thermostat can cause the engine to overheat.

It's important to address any issues with the cooling system as soon as possible, as overheating can cause serious damage to the engine. If you are not comfortable diagnosing and repairing the issue yourself, it's recommended to take your car to a qualified mechanic.

There are several reasons why your Mini may be overheating. Some of the common causes include:

1. Low coolant levels: If the coolant levels in your Mini's radiator are low, it can cause the engine to overheat.
2. Faulty radiator: A radiator that is clogged or has a leak can prevent coolant from flowing properly, causing the engine to overheat.
3. Faulty thermostat: A malfunctioning thermostat can prevent the coolant from flowing through the engine, causing the engine to overheat.
4. Faulty water pump: If the water pump is not working properly, it can prevent the coolant from flowing through the engine, causing the engine to overheat.
5. Blockage in the engine cooling system: A blockage in the engine cooling system can prevent coolant from flowing through the engine, causing the engine to overheat.
6. Overheating of other components: Overheating of alternator, A/C compressor, power steering pump, etc can also cause the engine to overheat as these components are driven by the engine and they add extra load on the engine.

If you suspect that your Mini is overheating, it's important to have it checked by a professional as soon as possible to prevent further damage to the engine.

Are the cooling fans coming on ? Go under the hood in the engine compartment , with the vehicle running have some one turn on the A/C , do you see and or hear the cooling fans come on ? Could be the coolant temperature gauge is bad ! How many miles on the vehicle ? Ever have water pump replaced ?

1

Check for a loss of system pressure.
Is there a loss of system pressure?
--
Go to Step 2 yes
Go to Step 3 no

2

Inspect and repair any faulty hose connections.
Does the engine still overheat?
--
Go to Step 3 yes
System OK

3

Check for low coolant protection (-37?°C/-34?°F).
Is there low coolant protection (-37?°C/-34?°F)?
--
Go to Step 4 yes
Go to Step 5 no

4

Test solution. Replace the coolant if necessary.
Does the engine still overheat?
--
Go to Step 5 yes
System OK

5

Check the water pump belt for low tension.
Is the water pump belt tension too low?
--
Go to Step 6 yes
Go to Step 7 no

6

Replace the water pump belt tensioner.
Does the engine still overheat?
--
Go to Step 7 yes
System OK

7

Check for an inoperative thermostat bypass.
Is the thermostat bypass inoperative?
--
Go to Step 8 yes
Go to Step 9 no

8

Replace the bypass.
Does the engine still overheat?
--
Go to Step 9 yes
System OK

9

Check the water pump.
Is the water pump inoperative?
--
Go to Step 10 yes
Go to Step 11 no

10

Replace the water pump.
Does the engine still overheat?
--
Go to Step 11 yes
System OK

11

Check the radiator fins for obstruction.
Are the radiator fins obstructed?
--
Go to Step 12 yes
Go to Step 13 no

12

Inspect and clean the radiator fans.
Does the engine still overheat?
--
Go to Step 13 yes
System OK

13

Check the cooling system passage for obstruction.
Is the cooling system passage blocked?
--
Go to Step 14 yes
Go to Step 15 no

14

Inspect and flush the system. Reroute or replace the hose if necessary.
Does the engine still overheat?
--
Go to Step 15 yes
System OK

15

Check the water pump belt for damage.
Is the water pump belt damaged?
--
Go to Step 16 yes
Go to Step 17 no

16

Replace the water pump belt.
Does the engine still overheat?
--
Go to step 17 yes
System OK

17

Check the cooling fans.
Are the cooling fans inoperative?
--
Go to Step 18 yes
Go to Step 19 no

18

1. Inspect the electrical connector. Replace if necessary.
2. Does the engine still overheat?

--
Go to Step 19 yes
System OK

19

Check the throttle body circuit flow.
Is the throttle body circuit flow restricted?
--
Go to Step 20
Go to Step 21

20

1. Inspect the orifice and associated hose. Replace if necessary.
2. Does the engine still overheat?

--
Go to Step 21
System OK

21

Check for a stuck thermostat.
Is the thermostat stuck in the closed position?
--
Go to Step 22
--

22

Replace the thermostat.
Does the engine still overheat?
--
--
System OK

replace thermostat did bleed coolant system check coolant level.because if not engine could have overheated and blowed headgaskets warp or cracked the heads check engine compression.sound like engine got too hot.

Thanks for choosing FixYa and welcome to the site. The thermostat is the most common issue with overheating. This is just a recap of other issues that can cause overheating. Be sure to check your coolant level and make sure you are not leaking coolant in the engine compartment. You may need to buy a new coolant cap. Make sure your fans are working properly. If they are not, check the fuse for the fans. Make sure your radiator is not leaking and working properly. Make sure there ae no damaged hoses or missing clamps. If all this checks out, it may be your water pump. If you have any questions, just let me know. Thanks for using FixYa.

If your car to overheat, it is very likely to be for any failure or some electrical defect in the cooling system. With the engine off, check for water leaks in the engine or under it, it could be internal leakage in the gasket, if this happened, I suggest you immobilize the car, but could damage. review of water and coolant levels if they are in the correct, it could also be a fault in the thermostat, water pump or the fan on relay.

Overheating is due to, well, the coolant in the cooling system getting too hot. In a normally operating engine, this should never be a problem. First, check that the coolant level is correct. If it is correct, I would suspect a problem with the thermostat. When the engine is cold, the thermostat closes off coolant flow through the engine until the coolant reaches a pre-determined temperature. When that temperature is reached, the thermostat opens to allow the coolant to circulate at that exact temperature.

Thermostats are known for failing and either not opening or not opening enough at that pre-determined temperature. This causes coolant to get trapped too long in the engine coolant chambers, heating it beyond limits, causing the engine temperature to increase and possibly overheat.

If my Maxima was overheating, I would check the coolant levels and then possibly replace the thermostat. It usually is no more complicated than that.

Keep in touch.

REMOVAL & INSTALLATION

2.0L Engine
See Figures 1 through 6

Fig. 1: Remove the coolant recovery tank hose from the water outlet

Fig. 2: Remove the upper radiator hose from the water outlet

Fig. 3: Remove the three retaining bolts for the water outlet

Fig. 4: Carefully separate the water outlet from the thermostat housing

Fig. 5: Remove the thermostat from the housing

Fig. 6: Make sure you replace the O-ring when installing a new thermostat

1. Disconnect the negative battery cable.
2. Drain and recycle the engine coolant.
3. Remove the air intake resonators.
4. emove the upper radiator hose and coolant recovery tank hose from the water outlet.
5. Remove the three retaining bolts from the water outlet and remove the outlet from the thermostat housing.
6. Remove the thermostat and O-ring from the housing.
   

To install:

1. Thoroughly clean the housing and install the thermostat and new O-ring into the housing.
2. Install the water outlet and tighten the retaining bolts to 71-97 inch lbs. (8-11 Nm).
3. Install the upper radiator and coolant recovery tank hoses to the water outlet.
4. Install the air intake resonators.
5. Connect the negative battery cable.
6. Fill the cooling system with the proper 50 / 50 mixture and start the vehicle.
7. Bleed the cooling system and check for leaks.

Hope this helps (remember to rate and comment this asnwer).

CAUTION
If the radiator is filled to the top with coolant and the engine is run without the radiator cap in place, the coolant will expand and spill over as the engine warms up.

• Drain some coolant into a clean container until the coolant level is below the thermostat housing.
• Remove the upper radiator hose connection from the thermostat housing.
• Loosen the housing bolts and remove the housing.
• Remove the gasket and scrape it carefully from the surface of the housing and the mounting surface on the engine. If the gasket remains on either of the surfaces, there will probably bea coolant leak after reassembly. Some engines use a rubber O-ring to seal a thermostat housing.
• Compare the size of the thermostat to the old one. They are of different sizes, types, and temperature ratings.
• The temperature rating is stamped on the sensing bulb on the bottom of the thermostat. The temperature bulb faces the block.
• When replacing a thermostat, be sure that the thermostat fits into the groove in the block or outlet housing. If the thermostat is installed upside down, the engine will overheat.
• Install the gasket.
• Reinstall the thermostat housing. Refill the system and run the engine or pressure test to check for leaks.
• When the engine has reached operating temperature make sure the thermostat opens.
• You should be able to see coolant circulating within the radiator.
• Another way of checking thermostat operation is to feel the top of the radiator hose or use a thermometer or multimeter with a temperature probe to confirm that the coolant is warming up.
• If the engine is overheating, but the top hose is still cool to the touch, the thermostat is stuck closed and must be replaced.

NOTE When a paper gasket is used and the recess is in the thermostat housing, it is a good practice to position the thermostat into the recess and glue the gasket to hold it in place. If it falls out of its groove during installation, the outlet housing can be cracked or a coolant leak will result. Before tightening the water outlet housing, try to rock it back and forth to be sure it is flush. Housings are often cracked during this step.

Check the cooling fan, its sensor, the relay, the fuse. On most cars the fan is not needed on the highway, but engine overheats it it doesn't switch on inside the city. Also, clean the system with a special liquid according to the directions on the can and use coolant after that, water causes corrosion. While pouring/filling/cleaning, keep the heat switch on max heating to allw circulation via the heating radiator.

Sometime a car will overheat it there is air int he system. You can buy a resivor that will screw tot he top of your radiator that is made for burping the system. This can be found at your local auto parts store.