Overheating questions

[Bim Turch]

I have an 03 v8, a few months ago I posted about an overheating problem where the fan would kick in and engine temp goes all the way up. it only happens when the car was idle, and the check engine temp message would beep. If I turn off the car and immediately turn it back on the temp would go back down. All I did was added a few OZ of water to the reservoir and it has been fine ever since. (low coolant)

This morning... same problem. Do I have a slow leak somewhere?...a sticky thermostat?, or do I need to just flush and refill( just hit 100,000 miles).. or any other suggestions ??

 

[lsdarkshadow]

Could be both. Cracked coolant oveflow tank? Check for leaks by drives front wheel well. Could be thermostat. Common problem, easy fix if you can hold a wrench. Also check to see how fast the fan is running, you could also/or have a bad cooling fan pump actuator. All three problems can be repaired at home with alittle dedication, and less than $100 per problem. Check Tech disscusions and and some previous disscusions as this is a VERY talked about topic and you'll find all the detailed directions on how to do each of these things.

 

[Smitty_2000LS]

Bim,
I have a 00 LS v8 and was having the same problem. i spent roughly 50 bucks parts and labor to have the thermostat replaced. havent had a problem since then

 

[joegr]

Could be both. Cracked coolant oveflow tank? Check for leaks by drives front wheel well. Could be thermostat. Common problem, easy fix if you can hold a wrench. Also check to see how fast the fan is running, you could also/or have a bad cooling fan pump actuator. All three problems can be repaired at home with alittle dedication, and less than $100 per problem. Check Tech disscusions and and some previous disscusions as this is a VERY talked about topic and you'll find all the detailed directions on how to do each of these things.

Just to clear up a few things.
The LS does not have an overflow tank. It has a degas bottle. The difference is that overflow tanks aren't pressurized.

The 03 (gen II) has an electric fan, not an hydraulic one, so no fan pump actuator.

 

[joegr]

At the very least, it is certain that your degas bottle has cracks at this age. You should replace it. Also, look very very closely at the big plastic assembly that the top radiator hose attaches to. There is a good chance that it the back part of the housing may have cracks in it. Also check where the little hoses attach to it.

You should have your cooling system flushed about every three years if you want the engine to last. The lubricants and the anti-corrosion additives wear out after three or four years and the cooling water starts eating the engine, heater core, and water pump.

 

[tireman]

Yep +1

Yep +1 on Joegr

try here for part

www.carpartsdiscount.com/auto/parts...nsion_tanks/coolant_reservoir.html?3593=48079

 

[The Hotness]

Bump for knowledge!

My Lincoln has been "overheating", CEL pull over and check it. No leaks, no smell, upper hose warm to touch, lower is cooler, has pressure, has fluid in degas. Start car up, no problems, back to normal.

Few days later, exact same thing.. Overheating, w/o actually overheating. Had a GTO that had the same problem.

 

[joegr]

Bump for knowledge!

My Lincoln has been "overheating", CEL pull over and check it. No leaks, no smell, upper hose warm to touch, lower is cooler, has pressure, has fluid in degas. Start car up, no problems, back to normal.

Few days later, exact same thing.. Overheating, w/o actually overheating. Had a GTO that had the same problem.

Your two biggest possibilities are:

1. Trapped air. Follow the cooling system bleeding instructions to the letter (see tech articles). If that clears the problem up for a day or two, then you know that you have a small leak somewhere. The most likely place is the degas bottle. It's also possible that the metal tube inside the degas bottle has come loose.
Search for the many times this has been covered.

2. Your hydraulic cooling fan has a problem. Search for the many times this have been covered.

A much less likely possibility is that you have an intermittent short in the head temperature sensor circuit.

 

[The Hotness]

Your two biggest possibilities are:

1. Trapped air. Follow the cooling system bleeding instructions to the letter (see tech articles). If that clears the problem up for a day or two, then you know that you have a small leak somewhere. The most likely place is the degas bottle. It's also possible that the metal tube inside the degas bottle has come loose.
Search for the many times this has been covered.

2. Your hydraulic cooling fan has a problem. Search for the many times this have been covered.

A much less likely possibility is that you have an intermittent short in the head temperature sensor circuit.

Searching is what got me to this thread.

Maybe possible on the intermittent short.. The car isn't appearing to actually overheat, no warm, no smell, no leaks, and not outrageously hot hoses. Its done it twice in a week and a half, not frequent, but I shall continue to monitor.

Thanks for the insight.

 

[joegr]

Searching is what got me to this thread.

Maybe possible on the intermittent short.. The car isn't appearing to actually overheat, no warm, no smell, no leaks, and not outrageously hot hoses. Its done it twice in a week and a half, not frequent, but I shall continue to monitor.

Thanks for the insight.

It could be a short, but be aware that trapped air in the cooling system will give pretty much the same symptoms. Only the cylinder heads overheat, so there would be no smell, very hot hoses, or very warm engine compartment. Your temperature gauge normally only indicated a normalized engine coolant temperature. When the head goes over temp, the PCM commands the gauge to go to the max hot position. When you shutdown, it can take less than a minute for the head to cool enough to not retrigger the warning.

Your easiest, cheapest first step would be to bleed the cooling system. If you get air out, then you know. If not, I would do a pressure test. If the pressure holds, then go looking for a short and replace the head temperature sensor.

 

[The Hotness]

Very good advice! Thank You.