cooling system

DougH

Registered User
I recently put in a OE Thermostat. The level in the coolant recovery tank does not go up when I drive the car up to operating temperature. Any ideas as to what the problem could be. Also I thought the engine was running hot, and I was told the temperature gauge was not working properly. Also the level does not go down when the engine is cool.
 
Remove the small rubber tube at the radiator fill neck and confirm it isn't blocked. See if you can blow thru it into the overflow tank.

As well, what process did you use to vent air when you closed it back up?

Is the connection at the temp sender on the thermostat housing clean and tight?

Did you use a new 16# radiator cap?
 
Is the car losing coolant? Has the level in the radiator dropped (from cold check to cold check)?
 
91 SC 18.000 original miles. I am the original owner

3 new belts
3 new Thermostats
2 new radiator hoses
1 new temperature sender
1 new 16# radiator cap
1 used fan relay module
new radiator

system was drained and filled 3 times already and bled
never had any issues like this until the new thermostat was put in which I didn't do
also the coolant level does not go down in the recovery tank when the engine gets cold
nutsville !
 
91 SC 18.000 original miles. I am the original owner

3 new belts
3 new Thermostats
2 new radiator hoses
1 new temperature sender
1 new 16# radiator cap
1 used fan relay module
new radiator

system was drained and filled 3 times already and bled
never had any issues like this until the new thermostat was put in which I didn't do
also the coolant level does not go down in the recovery tank when the engine gets cold
nutsville !
If you have a new sender unit, then your dash guage is probably spot-on. I have 3 SCs.... I've never had a sender+guage that was off. If you're seeing high temps AND the fan turns on when the needle get somewhere past the "o" but temps keep climbing, then your thermostat is not working! I'd take the thermostat out and bring it to a boil in a pan filled with water it to see if its working as its supposed to.

As for this bleeding rig-a-ma-roll everyone seems to have problems with... (big eye roll) :rolleyes:.. fill the radiator.. As suggested, blow through the overflow hose and make sure its clear. Fill the overflow tank to the upper line.. it really doesn't matter if you remove the burb cap.. replace the rad cap.. run the engine.. drive the car.. get it up to operating temp.. let it cool down.. refill the overflow tank to the lower line.. and you're Done! :cool:
 
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Also I thought the engine was running hot, and I was told the temperature gauge was not working properly.
Who told you that? :rolleyes: You can wiggle the connector on the top of the thermostat housing and if its reading anything at all, its probably fine. As I said in another response, I've never seen a "bad" guage. Ive have had loose connections however in which case the guage stays below the LH mark.
 
Car is not loosing coolant. Never had any cooling system issues ever until now. Blew through the rubber hose that goes to the coolant recovery tank, all good there. Car had no cooling problems at all until the Thermostat was changed. The mechanic changed and replaced 3 brand new ones and still had the same problem. Mechanic tested the temperature gauge and said it was bad. I have a brand new Motorcraft 97' stats in there now. Perhaps it was not installed correctly, and the Bridge was not in it ? Very much confused.
 
Why was the thermostat changed in the first place?

What temp stat is in use now? Stock should be 192ºF.
 
I had the original Thermostat in it since 91, never changed until now. When I purchased the new Thermostat at Ford Dealership, they said the OE was a 197 so that is what was put in it. I looked at the old one that came out and it was a 197 also. Is it possible that it was not installed with the Bridge in the housing ? I guess I should take it apart and get a look at it myself. So you are saying I should put a 192 in it instead ?
 
Who told you that? :rolleyes: You can wiggle the connector on the top of the thermostat housing and if its reading anything at all, its probably fine. As I said in another response, I've never seen a "bad" guage. Ive have had loose connections however in which case the guage stays below the LH mark.

Ahem.

TSB 95-13-2 .

'Nuff said.

RwP
 
You can verify proper operation of the thermostat by putting it in a pot of water on the stove with some type of thermocouple.
If the car has sat for a while it might not be a bad idea to flush the cooling system as well, crud has a way of building up.
Use the factory spec'ed thermostat it's either 192 or 195 if I remember correctly, also make sure the thermostat has the small bleeder hole in it as well.

Last but not least, MAKE SURE the gasket you are using on the t-stat housing has enough meat around the bypass hole to seal, some gasket makers punch that hole way too large not leaving enough surface area to seal properly , hence leaks.
 
Cooling system has been flushed 3 times in 2 weeks, with 3 brand new Thermostats put in and taken out. Also the cooling recovery tank is not working properly. The level does not go up or down when the engine is cold or hot. Blew through the line to make sure it was clear and it is. Is there any way the thermostat coulod be in wrong ? If the Bridge is not in there could be a problem ? Like I said Ford says the OEM thermostat calls for a 197. Not a 192 or 195. It is a 91 SC 6cly 3.8L., with the Turbo Charger. Anyway the water pump could be bad ? No leaks and no bad sounds coming from the pump.
 
Cooling system has been flushed 3 times in 2 weeks, with 3 brand new Thermostats put in and taken out. Also the cooling recovery tank is not working properly. The level does not go up or down when the engine is cold or hot. Blew through the line to make sure it was clear and it is. Is there any way the thermostat coulod be in wrong ? If the Bridge is not in there could be a problem ? Like I said Ford says the OEM thermostat calls for a 197. Not a 192 or 195. It is a 91 SC 6cly 3.8L., with the Turbo Charger. Anyway the water pump could be bad ? No leaks and no bad sounds coming from the pump.

Few things:

1. No reading between the lines on this site. People aren't angry or yelling, just stating things to "try" and help from another location. We aren't there to see what and how things have actually been done. There is a lot of assuming that happens.

2. The car is not a turbo charged car, it is a supercharged car.

3. 195 is the correct stat for an iron push rod block for a ford thunderbird 3.8L. The 94 and up are 197 as they are "Mod" engines.

4. Pull the stat and put it in a pan and heat up the water to 197 degrees. Drop that stat in and see if it opens or not? Another thing that can be done is to get the car up to temp and squeeze the top radiator hose. If it is too tight and wont allow the water to push out odds are it is either. 1 full of air or 2 the stat is stuck shut. If it is rock hard loosen the bolt out of the bleeder by the stat and see if air comes out or not. Put on long sleeves and leather gloves as the water if it comes out will be a touch warm.

5. Seen mechanics do weird things before and I would check that the stat is placed in properly. It's 2 bolts and a little liquid spilling and peace of mind.

Hope these items help. If a person doesn't want to do them and just takes the word of the mechanic that is their choice. If the stat was placed in the car incorrectly when it was swapped then it could have been placed the incorrect way the next 2 times as well if the mechanic just followed how they pulled it out.

These are suggestions to solving the problem.
 
The T-stat has to have a couple of features one is call "a jiggle pin valve" it allows air traps to neutralize, the other feature is "reverse poppet'

The reverse poppet thermostat opens against the flow of coolant from the water pump. The coolant, under water pump pressure, is used to help the reverse poppet thermostat stay closed when cool to reduce leakage. This type is engineered with a self-cleaning, self-aligning stainless steel valve

The offset thermostat with jiggle pin valves is equipped with a special valve in the flange, which allows trapped air in the system to escape and permits the venting of air from the system when filling it with coolant


Copied those descriptions from the Gates site. I haven't bought a Motorcraft 195 degree for T-bird SC in quite some time, but they had both feature, reverse poppet and jiggle pin.

The jiggle pin must be positioned at 12 o'clock.

Don't quote me on this one I thought our t-stats looked like they were installed backwards, spring side facing away from the block, but the Haynes manual is not showing it that way.





Hope this helps a little
 
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Cooling system has been flushed 3 times in 2 weeks, with 3 brand new Thermostats put in and taken out. Also the cooling recovery tank is not working properly. The level does not go up or down when the engine is cold or hot. Blew through the line to make sure it was clear and it is. Is there any way the thermostat coulod be in wrong ? If the Bridge is not in there could be a problem ? Like I said Ford says the OEM thermostat calls for a 197. Not a 192 or 195. It is a 91 SC 6cly 3.8L., with the Turbo Charger. Anyway the water pump could be bad ? No leaks and no bad sounds coming from the pump.
It would be hard to install the thermostat incorrectly, but with a lot of determination.. who knows.. ;) As for the temp.. 192-197.. are in the ball park... if working correctly, you shouldn't be able to tell. It is a remote possiblity that the water pump is not pumping coolant, but I've never seen one fail that badly that didn't leak all over first.

As for use DIY guys.. I, for one, don't like to depend on mechanics very much with the 90 SCs.. even Ford guys. Partly due to the age of the car. Im a bit surprised that you're having trouble with such a low mileage car; It makes me wonder what a mechanic could do wrong (or not notice some other problem such as a blocked hose) that could cause the thing to overheat like that.

Just to clarify.. it IS overheating, correct? Or is it just that you're not seeing the coolant rise in the overflow tank. Hopefully we're not chasing a problem that isn't a problem. If the coolant tank isn't rising but the engine is not overheating.. then all you may need to do is just wait for it to be cold.. top the radiator off.. and just check the tank every week or so and just Drive on! :D
 
I find that the level in my overflow tank fluctuates more in cold weather. Right now (avg. high around 90º lately, and maybe 60~65 at night), it moves less than an inch, if that much. When it's cold outside, it moves happily from HOT down to COLD on the tank. Note I run an aluminum radiator, 16# cap & 192º stat if that matters.

Once the system is closed up, resist the urge to repeatedly remove the radiator cap and check the level there.

What are you seeing on the stock temp gauge...does the needle come up more than half way or sit low or?

Water pumps don't need to leak to show distress. They can suck air at the seal or in some cases, the impeller can wear down and just not move water, but these days I think that would be rare indeed. Did someone look close at the weep hole on the snout? Has the system been pressure tested? Any water in the oil?

What concentration anti-freeze and water are you running?
 
I hear you TbirdSCFan about mechanics touching these vehicles. There is no one left or very very few at Ford garages that ever worked on these. Even when I had my 90XR7 in Toronto up to 2008 when I moved Ford guys were very hard to find. Our club Prez Fast Ed worked at a Ford shop and said few knew about them.
 
On low mileage cars not driven for mths on end it's not unusual for the intake manifold gasket to let go.

Ask me how I know.:eek:

Paul
 
They may be what looks to be reversed, i can't remember. I have never seen one that the spring did not face the hot water though.
 
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