Finding over heating problem in a 97 sevill cadillac

Do not continue to operate. Operating an overheated engine will cause the engine to fail.

After the engine has cooled,
Confirm that the engine has coolant.
Confirm that the reservoir is full to the mark
Start engine and confirm as engine gets warm cooling fan at radiator turns on

Confirm that the rubber engine belt is working
Put in car heater to full hot and blower on.
Confirm heat is hot from car heater.
If heater is not hot possible water pump failure or air in coolant system keeping the coolant from circulating.
Allow to cool completely.
Remove cap start engine and observe coolant flowing at or near cap. Observe bubbling or exhaust gases coming from radiator

Check for water in oil by pulling dip stick

• White smoke from the exhaust pipe
• Overheating engine
• Bubbles in the radiator or coolant overflow tank
• White milky oil
• Significant loss of coolant with no visible leaks

If milky likely a blown head gasket

Hope this helps?

Hi Marina,

This sounds like a low coolant (anti-freeze) level related problem.

After the car has been sitting for hours and the engine is COLD (over night is ideal), check the coolant reservoir of the car. Fill the reservoir with a 50 / 50 mixture of coolant (a type approved for use in your car) and water to the COLD line.

Remove the radiator cap - again - the engine MUST be COLD. The coolant should be visible about 1 - 2 inches in the radiator filler neck. Top off the radiator with a 50 / 50 coolant and water mixture as needed to get to the 1 - 2 inch level described above.

Leave the cap OFF and start the engine.

Turn the heat to HOT and fan on.

You should begin to see the coolant in the radiator begin flowing as the engine warms up. If at any time the coolant level in the radiator drops, add additional 50 / 50 coolant and water mixture as needed to get to the 1 - 2 inch level described above previously.

As the engine warms, the coolant will expand slightly and may begin to overflow from the radiator filler neck. At this point, replace the radiator cap SECURELY. If you needed to add coolant at any time in these steps you should have heat now. If not, try driving the car until the car engine reaches normal operating temperature.

If you're still unable to get heat, there may be a clog in the heater core or hoses that supply it; air trapped in the heater core circuit or other issue that will need a mechanic to repair.

Regardless if you have heat or not: Check for puddles of coolant under the car. You may have an inexpensive repair to fix a leaking hose or fitting. After the engine is hot check the exhaust pipe for white wispy "smoke". When first starting, this is common - but after hot - the exhaust should be clear. Wispy "smoke" is really steam from coolant leaking into the combustion chamber. This could be the cause for your coolant loss. This also indicates a much more expensive repair problem or either a damaged head gasket $$ or cracked engine block $$$$.

Good luck!

Most likely have a coolant leak somewhere. Could be the radiator, hoses, coolant reservoir, water pump. Get it resolved asap, wouldn't want to pull over to have your car rolling in it's coolant..

This most certainly sounds like a water pump issue. The thermostate is located inside the water pump housing and if the pump is bad you'l lose fluids and need to add every day or so. The temp guage will run hot and often the heater won't warm up. You have even notice fluids on the ground below the front passenger side of the car. Try getting a pressure test first before replacing anything. That's a good place to start the diagnosis.

Now that you've eliminated the thermostat, it could be a number of other things. Don't drive the car too far until you've fixed the overheating problem - overheating can destroy an engine.

That split ribbed hose you see is plastic wire loom - it carries and protects electrical wires, and is not the cause of overheating.

1. Low coolant level
2. Radiator hose split/cracked, causing low coolant level.
3. Head Gasket - leaking, causing low coolant level
4. Thermostat - stuck closed (you eliminated this possibility)
5. Radiator cap - worn/damaged
6. Radiator fins - obstructed by debris/cardboard
7. Water Pump belt - missing/broken
8. Heater Core - leaking, causing low coolant level
9. Intake Manifold Gasket - leaking, worn, damaged
10. Radiator Fan Relay - faulty
11. Radiator Fan Blade - broken, missing
12. Radiator Fan Sensor/Switch - faulty
13. Water Pump - leaking, causing low coolant level
14. Radiator Fan Motor - faulty

My primary suspects would be Rad Fan Relay (#10), and
Rad Fan Switch (#12).

No. It is not the thermostat. You are just low on coolant. The reason for the low coolant is either the fan is not working, the head gasket is blown, or the coolant system has a leak.
The fan is easy to check. When the temp comes up then the fan should come on.
The head gasket is easy to check also. Your oil will be milky white.
And if the radiator, radiator hose, or gasket leak can be harder to find.
The heater not working is because there is not enough water to heat the heater core.
PLEASE RATE. By checking Four thumbs ups!
Thanks! Have a GREAT DAY!

There may be a leak or the radiator cap may no longer prevent the steam from escaping. check the radiator fans if they are turning. You can check the fan if it is working by pulling out the temp sensor at the lower radiator hose near the engine. The fan should blow at full once you unplug it. Check also the water pump in the engine if there are leaks. You may have it replaced. Check for white smoke at the exhaust, if there is and it has sort of a sweet smell you may be loosing coolant to the cylinders because of a bad head gasket.

Check your coolant. If the coolant is low, you won't get heat in the cabin. Make sure that the fan is turning on as well. Check coolant sensors also. Good luck!

This could be the radiator, a radiator hose, or a heater hose. The only way to find out is to fill the system, start it up and watch to see where it is coming from. It would help to purchase a small mirror at a auto parts store that can be moved around the leak area to hopefully give u a view of the source of the leak. I don't think this is the water pump, as they usually begin to leak slowly and get worse over time, not a 'gusher' like u described. The white smoke is the coolant escaping in vapor form, or/and coolant coming in contact w/ the hot exhaust system. U won't harm the engine if u fill the system before checking, and turn it off before the temp. gauge rises past the normal range. If u can't find it in that time, let it cool down, and refill system, and repeat your detective work. U might also want to raise the front end (ramps or safety stands, and check from underneath for leak source. Let me know what u find.

Hi,

Possible causes of overheating are:

• stuck thermostat. In my country, some mechanics even remove entirely the thermostat (not applicable on cold weather);
• faulty water pump;
• too soft radiator hoses (upper and lower);
• faulty/slow radiator fan. Again, in my country, some mechanics hard wire the radiator fan to be always on when the engine is running. In some cases, it could be the fan clutch.

This is of course assuming that nothing is internally wrong with the engine, the coolant level is as required and that there are no leaks, air bubbles and the belt driving the water pump is mechanically sound. In most vehicles, the radiator fan will not work if the A/C or heater is not working.

Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards. Thank you for using FixYa.