pardegt

My parents have a 96 duratec sable wagon where the temp needle usually would go up about 3/4 of the way and sometimes within an 1/8" of the hot mark. I performed a Prestone chemical flush with no results. The heater blows hot, hoses seem ok, and both fans come on and stay on when they should. Also, I have changed the water pump and thermostat in the last couple years.

I just got done replacing the motor due to broken valve spring and dropped valve that shattered the piston and tore a hole through the block. I swapped the newer water pump onto the donor, but used the sensors that came on the donor motor. Temperatures on the gauge remain the same. So, I went ahead put in a new radiator. Old one was pretty dirty so was probably not as efficient as it should be, however, the temps are still almost the same.

Oh, at one point I also put it on a scan tool and verified the ecm was seeing temps same as the gauge...around 235 deg

Good news is donor motor runs great. The only thing left is that it is throwing a code for an oxygen sensor (bank 1, sensor 2)...I have to figure out which one that is. Could that be what is causing the temps to run high?

Is there an air bleed procedure that I don't know about?

What else could it be???

Thanks for your replies.

R.S.LOGAN

I would take out the thermostat and check the temp on it . From someone with the same problem ,

" I did try to use Stant - the one at AAP is the 195F - wrong temperature .The Motorcraft one is 190F (actually it was stamped 87.5C) and temperature needle sits horizontal."

pardegt

I see there are several to choose from rockauto.com

How much difference can one expect to see from the thermostats listed for this engine?

180
188
190
195

I don't remember what I put in (1+ yrs ago) but would have asked for what was stock and probably used Stant brand.

FordMan59

Bank 1 sensor 2 would be the 02 sensor after the catalytic converter on the bank of cylinders containing 1-3. The only thing the sensors after the catalytic converter do is monitor the converter efficiency so that's not what's causing the overheating problem. If it were a bank 1 or bank 2 sensor 1 it would effect a/f mixture and if the car was running too lean it would increase engine operating temperature.

If the radiator cap is not holding enough pressure that could cause the car to run hot. Are you losing any coolant? If so it's possible you have a blown head gasket.

R.S.LOGAN

Could try the earlier opening one , should make a difference .

chipset

Factory recommended temp for that engine is 180 but most run 192. 180 is bare
minimum to operate any temp activated sensor. The 02 sensor has absolutely nothing to
do with your over heating problem. You have 2 different problems and they are not
related. My 02 sensor actually broke off the pipe. Drove it or 2 months that way and never over heated. Little hard on gas but ran just fine.

pardegt

If the thermostat that is in there now would happen to be a 195, would that alone be enough to be causing the temps to rise this much since 190 deg is stock?

I don't think this is an issue with the motor as it was present before the swap and the donor engine is not losing coolant. I only reused the water pump, hoses, and thermostat in the swap (related to cooling).

One interesting note is that one will be driving and the dash gauge is reading almost to 1/8" from the white line next to the red H and then suddenly it will drop about another 1/8" cooler before slowly climbing again. Fans are on way before this takes place. Also, the system does not seem to build a lot of pressure in the hoses, specially for as hot as this thing is getting.

jwko

I just did a little reading and found that the thermostat is in line with the lower radiator hose instead of the upper hose. Could it be possible that the thermostat has been put in upside down? According to the diagram it looks possible and wouldn't allow it to open much. Just a shot in the dark.

chipset

Pardegt. You didn't read. 190 is not stock. 180 is. No the stat cannot be put in upside
down. It won't fit. When your temp needle moves 1/8 inch to the cool side tells me your
stat is opening. What does the mechanical temp gauge say ? How do you actually know
it's over heating ? Do you believe everything an electronic gauge says ? The below stat
in the lower hose is a bloody might mare. Honda has those too. If it is not bled properly
and ALL the air is not out it will over heat. The lower part of the rad is the coldest part
of the engine. the engine has to get awfully bloody hot to have the stat open that is why the factory recommends a 180 stat. By the time that under slung stat opens the
engine could very well be over 200 degs.

pardegt

Chipset...ok, sorry I did misread but I also recalled that the motorcraft thermostat listed on Rockauto (only 1) is rated at 190 and it was stated above that 192 is widely used. Both sensors, the one feeding the gauge and one telling ecm read hot (ecm = 235 deg). Also, this condition was present with the old engine and I am using the sensors that came with the donor motor now, so I am pretty sure the problem is not with the sensors.

In my first post I asked about the possibility of having air in the system as I have not found anything on how to bleed this system. How do you go about bleeding it?

JWKO, yes, I thought the same thing and during the swap I checked and as Chipset stated, it will only fit one way and it is a bear to get to due to the inlet housing sitting right above the subframe.


EDIT...I did just find this:

with a cool engine, pop hood remove radiator or reservoir cap
turn on engine and ensure proper level in radiator or reservoir
turn heat in car to high and full blast
press the top radiator hose in firmly a few times and monitor the rad/reservoir see bubbles come out
refill if needed to proper level
let it run a bit until it starts to get a little warm
replace radiator/reservoir cap

Anyone use this technique to bleed??