91 LeSabre

It started running warmer than usual, just over 200. It takes longer to blow warm air by the heater than it used to, and after it does get warm it may turn cooler after a while. Today it started to get the the red area for temp and seems to lose some power. I shut it off as soon as I seen this and let it sit for ten minutes. Started it up, started fine, and the temp was back down to the 200 range. Got it home no problem. As I was driving in the city it did tend to warm up when driving slower. If I stepped on it going 40 it would drop in temp considerably. It does blow warmer from the drivers side more than the passenger. I did change that device under the glove compartment a year ago or more when it was doing the warmer on one side than the other then. The fans are working. The thermostat was changed maybe 1.5 yrs ago. It does not get driven much outside of winter. I have noticed it has been revving a little higher than normal over the last week. Once it did stall after I started it, but started fine since and never stalled again. As I parked it I did hear a somewhat of a small grinding noise from the right side of car near the water pump.

Would like to get thoughts one what this would be. Was thinking possibilities would be thermostat, water pump or head or head gasket problem. But does a water pump have anything to do with the heater being warm as it should be? Maybe if its not pumping good enough? What are you guys thoughts on that?

It sounds like there’s air trapped in the cooling system.


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What engine? What is the coolant level, only check it when the engine is cool. Also check the oil cap, if you see a chocolate shake sludge on it a head gasket is leaking. Some of the V6’s of that vintage had an intake gasket that frequently failed, overheating was the early warning sign.

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I believe its a 3.8. I did fill the antifreeze the other week. Was maybe a half gallon low or close to that. I will check it tomorrow. When I filled it I do recall some kind of film on the cap perhaps, seem to recall it more of a white slim. Could be wrong on that. But thank you I’ll check that tomorrow.

That would cause it to run warmer and perhaps overheat?

If the air gets to the water pump and causes the coolant flow to stall, the engine can start to overheat.


How do you remove a pocket of air?

I fill the cooling system.

Start the engine and let it idle until it reaches operating temperature.

I then loosen the upper radiator hose clamp, and slip a small flat bladed screwdriver between the upper radiator hose and the hose neck on the radiator.

I let the engine idle until all the air is purged from the cooling system.

Remove the screwdriver, tighten the hose clamp, and wait til the engine cools down to check the coolant level.


Probably the 3.8L, but it might be a 3L. That was the base engine starting in 1986, but I’m not sure how long that lasted. The next generation was available only with the 3.8L.

What I do is remove the thermostat, buy a new thermostat and gasket, drill a small (1/8") orifice in the new thermostat, and install it with the orifice facing up. Then, as I refill the coolant, I gently squeeze the upper radiator hose, and any air trapped on the other side of the thermostat will bubble through, allowing coolant to fully fill the system.

After the thermostat opens, add coolant as needed. After road testing and cooling off, check and add coolant as needed.

If you loosen a hose clamp with the engine at operating temperature you might get showered with 200 degree coolant, cooling systems develop pressure as they heat up.

The antifreeze was pretty low. Took a gallon to fill it up. Good news is the oil level is not up nor does it have any water look to it. Its good and black. Needs a oil change soon. I haven’t noticed any leaks. I have not driven it since Thursday. Might drive it to church Sunday for a short drive.

It needs an oil change yesterday.

As far as the coolant issue is concerned, you may have leaking intake manifold gaskets. Symptoms of Bad or Failing Intake Manifold Gaskets | YourMechanic Advice

Its a bad waterpump. Got a slight leak by the pump and starting to get worse. Ordered a new pump. Will have it fixed next week. I’ve parked it until I get the pump in the mail.