engine over heat, and sound that rises with acceleration

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Dwian

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I have an 01 LS V8 175k milesthat has recently started overheating, once normal operating temp is reached a"fan?" sound starts getting loud, gets louder with acceleration. I have checked for leaks and found none, system appears pressurized since when removing cap i can hear the pressure release. A short ride across town and temp redlines, says check engine temp, then engine power reduced, but no idiot lights, where do i start?:eek:
 
Dwian said:
I have an 01 LS V8 that has recently started overheating, once normal operating temp is reached a"fan?" sound starts getting loud, gets louder with acceleration. I have checked for leaks and found none, system appears pressurized since when removing cap i can hear the pressure release. A short ride across town and temp redlines, says check engine temp, then engine power reduced, but no idiot lights, where do i start?:eek:
Click to expand...

You may have air in the system, and need to bleed it out. instructions are in the tech articles on the top of the page.

But that air had to come from somewhere, which leads me to believe you probably have a cooling system component cracked and failing. common failures on 2000-2002 model years is the degas bottle and the thermostat housing/water outlet pipe.

however it could be something as simple as the degas bottle cap.

year/miles/engine?
 
01 3.9l V8 175k miles, what about the fan sound? That normal with a leak? I have checked and found zero leaks and has pressure, has been fine for a long time. Could be as simple as a water pump or thermostat?
 
i have the same symptoms right now, and i have a cracked water outlet pipe. i could hear it hiss when it was hot. new aluminum part came today.

i suppose your hydraulic fan could be failing. but i would hope it wasn't that. the most expensive fix for sure. actually, that sounds like a probable issue. though the fan is supposed to kick in if You are overheating.
 
Go to auto zone and grab some trans tune by sea foam and give that a try in the hydrolic fan it helped free my actuator up. Just a shot in the dark.
 
Dwian said:
01 3.9l V8 175k miles, what about the fan sound? That normal with a leak? I have checked and found zero leaks and has pressure, has been fine for a long time. Could be as simple as a water pump or thermostat?
Click to expand...

The fan (gen I - hydraulic or gen II - electric) will get very loud as the PCM will command it to max speed when it looks like the engine is heading towards overheating. This assumes that you are talking about a loud fan blowing noise, and not some other noise.
 
Well the fan appears to be running properly after further inspection.
I did find the radiator is not getting warm at all and my heat is weak at best.
Thinking water pump. Any thoughts?

Also the degas cap seems to be holding pressure.
 
Dwian said:
Well the fan appears to be running properly after further inspection.
I did find the radiator is not getting warm at all and my heat is weak at best.
Thinking water pump. Any thoughts?

Also the degas cap seems to be holding pressure.
Click to expand...

Yes, your LS is probably the single exception in history to the problems that every other LS has had.
Otherwise, no it's not the water pump. It's air trapped in the system from small cracks in the plastic parts. No, you won't see the leaks unless you are good at recognizing the signs of dried up coolant residue. No, you won't see the cracks in the degas bottle without removing it. Yes, even with the small cracks, the system will have some pressure. No, it won't work correctly after you replace all the cracked parts unless you follow the air bleed procedure to the letter.
 
If the radiator's not getting warm, then it sounds to me like the thermostat is stuck shut. I've seen at least one thread here where the plastic thermostat housing was the problem as it broke, jamming the thermostat. From how hard it apparently is to bleed the system (I've never had to do it), I'd go ahead and replace all the plastic parts in the system since they are known problems with the car.
 
I wouldn't say its really hard to do, there are just certian steps to do, some of those steps can take some time between them, and there are always some people who wont/cant follow directions.
 
Well, when some folks have to redo it several times, it sounds like it's hard to get it right. There's physically hard to do, then there's procedurally hard to do, and this bleeding thing sounds procedurally hard.
 
Telco said:
Well, when some folks have to redo it several times, it sounds like it's hard to get it right. There's physically hard to do, then there's procedurally hard to do, and this bleeding thing sounds procedurally hard.
Click to expand...

Really, it's easy. It's just that you have to follow the procedure exactly, in the exact order, even the parts that you don't think will make any difference.
 
if you can read very easy to follow directions, then you can properly bleed the system.


most people just dont want to wait the right amounts of time between some of the steps.
 
pektel said:
i have the same symptoms right now, and i have a cracked water outlet pipe. i could hear it hiss when it was hot. new aluminum part came today.
Click to expand...

Where did you get the aluminum water outlet pipe? How much was it?
 
Telco said:
If the radiator's not getting warm, then it sounds to me like the thermostat is stuck shut. I've seen at least one thread here where the plastic thermostat housing was the problem as it broke, jamming the thermostat. From how hard it apparently is to bleed the system (I've never had to do it), I'd go ahead and replace all the plastic parts in the system since they are known problems with the car.
Click to expand...

Dwian has a Gen 1, which doesn't have that problem. Gen 1 uses a traditional style thermostat, while Gen 2 has that funky multi-part deal where the housing can cause problems.
 
Pump whine

I have a 2000LS 3.9L and had the cooling pump rebuilt.Now the pump whines like it's low on fluid or under heavy load.The noise matches the rpms but only starts when the car is warm.The fan never kicks on high so i purchased a pressure switch but a friend said the whine wasn't because of the switch and that the pump was rebilt wrong.Any ideas?
 
Boniac360 said:
I have a 2000LS 3.9L and had the cooling pump rebuilt.Now the pump whines like it's low on fluid or under heavy load.The noise matches the rpms but only starts when the car is warm.The fan never kicks on high so i purchased a pressure switch but a friend said the whine wasn't because of the switch and that the pump was rebilt wrong.Any ideas?
Click to expand...

The wine is due to the pump being bad, the hydraulic system not being correctly bled, or a small leak on the suction side.

The failure of the fan to go to high speed is either the actuator (it's a solenoid valve, not a "pressure switch"), or your hydraulic pump is defective.
 
Yeah im trying to decide on getting the pump rebuilt again or just buying another.Of course the shop swears the work was done properly.The actuator wouldn't cause the whine at all would it?
 
All better

Replaced the thermostat and rebleed the system, no problems since.:cool:
 
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