We just purchased a 2001 Oldsmobile Aurora from the auction for our grandmother; we test drove it seemed to be fine, we got on the highway and it started overheating said to pull over immediately we did; had it towed home; have replaced the water pump and the thermostate still over heating; we have checked the oil there does not appear to be any water in the oil.
Any suggestions or ideas would be appreciated?

 

One thing to check is that the hose / fittings on the reservoir are not blocked. This is the only way to fill the radiator and block. So it may appear to have proper water level when in fact there is not enough in the system. Should take at least 1 to 1.5 gals.

 

this is a northstar caddy engine there a couple things here that need to be done first verify the weep hole in thermostat is pointed to 12 oclock also get the car on ramps so the front end is up the trick is to take the car up to 4500 rpm and back two idle three times with the heat on full boar and the temp raised all the way up this motor needs to be perged and have al the air removed from the system or it will not circulate coolant if this doesn't work get it to a dealer to have the system perged or it can cause major and i do mean major issues and its a bout 2000 dollar to replace used if ya can find one good luck with it but remeber ya wanna watch the motor burp if ya doing it at home

 

also check the thermostat housing most 4.0 auroras do have a bleeder screw that ya can crack lose while its on ramps to bleed the air out of the system and is easily done with system closed up its pretty much like bleeding brakes

 

There is No bleeder valve on the 2001-2003 Aurora 4.0's (not Northstar caddy engines either)

 

Well, I feared the worse when my 2001 aurora I bought at an auction kept overheating. There was a hole at the top of the radiator that someone drilled a hole into and screwed a fine-thread bolt into. I flushed the coolant system and replaced the thermostat and radiator, idled it and it was fine.... Until I drove it and got up to 60 and it started to spike in temp. Tried the "Cadillac Pills" and nothing. Seems that it's a leaking head gasket that puts combustion gases into the coolant system creating steam and air pockets and over heats it. So my last ditch effort will be to flush the system and add the Blue Devil gasket sealant to try and repair it otherwise it's going to be tearing the head(s) off and replacing the head gasket and head bolts and checking the head surface. Anyone else been in this situation!? Much help appreciated!

 

I bought the Car Used and it had a cracked Radiator so I bought new radiator and installed it and all seemed Ok for a while but occaisionally it would randomly overheat
I replaced thermostat and it was Ok for a while but now and then it would overheat. I would let it sit for a while and then drive home
Next time I replaced water pump and installed the higher priced thermostat with lifetime warranty and still it overheats intermittenly

I am now suspecting a Blown head gasket as the water Jacklet builds pressure too rapidly in my opinion. I really dont want to Tear the top of this engine

I figured out that the pressure in the system is building so fast that when the thermostat tries to open it cant overcome the High pressure
the Radiator cap is 18 Lb So I bought a 7Lb Radiator cap and the problem seems to be fixed.

the 7Lb Bleeds off the exhaust gasses and keeps pressure from going above 7Lbs per square inch
now the thermostat can successfully open

Auto Zone part numbers are 7018 = 18lb I now have 7007 7Lb wow now I can keep the car
and drive it and not have to worry about the thermostat sticking

 

the Lower Pressure radiator cap seemed to help but occaisionally it still overheats

It has overheated when the resivor is full this car has been the greatest curse that I have ever endured as far a car goes.

It seems like the thermostat is still sticking. I just read a post that the weep hole in the Thermostat has to be at 12 oclock position

I was not aware of that but I was thinking of just taking themostat out for a while and see how it runs

Winter is now over so I may be able to get away with it for a while.

Sometimes when it overheats I dont even have heat

I have tried reving it to 4500 rpm and back several times and that usually produces heat for a while.

I do fear that this engine now has a blown head gasket

any advice ?

 

Update on the 2001 Olds Aurora 3.5L shortstar V6 that is still overheating I Ran compression check 170-180-180 Rear banks front banks 170-179-179

So it is not a blown head gasket. I saw some people saying that aftermarket thermostats are Junk and that Ineeded a OEM thermostat so I figured that it would be worth it if the problem was gone. So I spent the 128 dollars for the factory thermostat with housing that is new that comes with it

I was figuring there is a design flaw with the housing causing the termostats to not open.

Installed and it still oveheats

I have heat inside the car but no coolant seems to be flowing into radiator the Fans are on but cold air comming out of radiator when car overheating

this car has been a real money pit any help

today I plan on removing thermostat

 

I took the old thermostat in the housing and stuck it in water and turned on the burner and heated the water and used a turkey thermometer and the thermostat opened at 185 degrees and was fully open at 190 and of course the new thermostat that is OEM did not fix the problem.
I had replaced the water pump last year when my air conditioning pump bearing went bad
I had misdiagnosed it but it has an after market waterpump now.

Unfortunately I long ago threw away the OEM waterpump.