Somethings not right!

WardL · #1 (**permalink**) 05-30-2011, 09:54 PM

Last October I installed a new 180 F thermostat and it worked great. My cooling water ran about 75 C (167 F). I just went for a ride and noticed the water temp never got over about 50 F (122 F). When I got home I let it idle until the cooling water got up to about 93 C (200 F) when the fans kicked on. Of course I don't want to drive around with "cold" cooling water, so I'm wondering if there is anything else that could cause this besides a stuck open thermostat. I find it hard to believe the Thermostat has failed already.

Gaz64 · #2 (**permalink**) 05-31-2011, 03:53 AM

Your thermostat is stuck open.

Thermostat controls minimum temp, radiator and airflow controls max temp, within reason.

mln385 · #3 (**permalink**) 05-31-2011, 07:13 AM

That or you have an air pocket in the system.

mpanten · #4 (**permalink**) 05-31-2011, 07:29 AM

Quote:

Originally Posted by mln385

That or you have an air pocket in the system.

That would make it run hot, in about 30 seconds.

Silverback51 · #5 (**permalink**) 05-31-2011, 07:45 AM

Quote:

Originally Posted by mpanten

That would make it run hot, in about 30 seconds.

Unless the air pocket is where the temperature probe is located. Then it will show a lower temp on the gauge.

jhv48 · #6 (**permalink**) 05-31-2011, 08:01 AM

Did you drill holes in the thermostat prior to installation?

If not, your thermostat is stuck open, or it is opening way before it is supposed to.

And, yes, they can be defective right out of the box.

Replace it and your problems will disappear.

Cobra446 · #7 (**permalink**) 05-31-2011, 01:47 PM

you need to bleed that air out of the system!

DAVID GAGNARD · #8 (**permalink**) 05-31-2011, 02:15 PM

Take out the thermostat, put in a pot of water on the stove and let it cycle 3 or 4 times, betting it's sticking open, if so, throw it away and get a new, test the new one on the stove before installing, I've had a new one stick open on it's first cycle out of the box........

David

WardL · #9 (**permalink**) 05-31-2011, 09:43 PM

I topped off the coolant with the engine cold. I warmed up the engine in the driveway after shutting down the engine, I heard it gurgle a little (Maybe to the overflow reservoir). It warmed up fine and the fans kicked on at about 92C (198 F) and it dropped to about 80C (176F). On the freeway, the water temp cooled to about 50C (122 F). Pulled over let the water temp warm up to 80C and back on the freeway where it cooled to about 50C again. The oil temp was around 70 C. The weather here is cool at 55 F. After all that, I can't believe it, but I must have a stuck thermostat! I don't think I have an air pocket and I didn't drill or have any holes in the thermostat. It still doesn't seem possible! I'll get a new thermostat tomorrow! RATS! Thanks for the ideas and suggestions.

Calbullet · #10 (**permalink**) 05-31-2011, 10:00 PM

WardL, my car does the same thing, you have to remember that a SPF has a excellent cooling system. When the air temp is cooler, I have to block off half my radiator to keep the heat up on the freeway.

FOMOCONUT · #11 (**permalink**) 05-31-2011, 10:12 PM

Ward, what was the problem with the thermostat last oct. SPF # 2773 Jerry

DAVID GAGNARD · #12 (**permalink**) 06-01-2011, 03:59 AM

Quote:

Originally Posted by Calbullet

WardL, my car does the same thing, you have to remember that a SPF has a excellent cooling system. When the air temp is cooler, I have to block off half my radiator to keep the heat up on the freeway.

On cool days say,65 degrees or less my Mustang will run at around 170 degrees on the highway with a 180 thermostat...I have a thin piece of cardboard about 8 inches square I stick in front of the radiator at the bottom to keep it at 180...........I have a big aluminum radiator,very efficeint........
Ward, the main purpose of the little holes in the thermostat is to purge the air when filling your cooling system to help eleminate air pockets.......

David

madmaxx · #13 (**permalink**) 06-01-2011, 06:27 AM

Next time when filling the radiator loosen the temp sending unit on the manifold and let the air bleed out, when you see coolant tighten it up, you will have no air.

mpanten · #14 (**permalink**) 06-01-2011, 10:36 AM

Quote:

Originally Posted by WardL

I topped off the coolant with the engine cold. I warmed up the engine in the driveway after shutting down the engine, I heard it gurgle a little (Maybe to the overflow reservoir). It warmed up fine and the fans kicked on at about 92C (198 F) and it dropped to about 80C (176F). On the freeway, the water temp cooled to about 50C (122 F). Pulled over let the water temp warm up to 80C and back on the freeway where it cooled to about 50C again. The oil temp was around 70 C. The weather here is cool at 55 F. After all that, I can't believe it, but I must have a stuck thermostat! I don't think I have an air pocket and I didn't drill or have any holes in the thermostat. It still doesn't seem possible! I'll get a new thermostat tomorrow! RATS! Thanks for the ideas and suggestions.

Im not sure you really have any problems, at 55 degrees mine does not get much warmer than that and I know the oil does not get warmer. I would try the thermostat and bleed it but if that does not change anything i wouldnt loose to much sleep over it.

Frank Messina · #15 (**permalink**) 06-01-2011, 03:09 PM

Your thermostat is stuck, Go to your Ford dealer and get a 192° Motorcraft thermostat. Your engine will thank you. Modern engines with aluminum heads need more heat for best thermal efficiency. Old habits have us overcooling our engines. You'll be surprised how much better your engine will run. Some time back I tested several brands of thermostats and the Motorcraft were the only ones that opened at the stated temp.
Frank

WardL · #16 (**permalink**) 06-01-2011, 08:27 PM

Plenty of good words of wisdom here, thanks! The Motorad Fail-Safe 180 F thermostat had failed open. The parts store only had a 192 F and Like Frank, I was thinking it would be OK. After getting back home I remembered the Roush book saying 180 F. After looking online, it seems the fail-safe thermostats have a tendency to fail regularly. One guy said he was on his 5th fail-safe thermostat and was happy with them! Maybe anytime the temps get 20 F above the set point they fail open. I don't want to be changing my thermostat every time it gets hot. I am going to get a 180 F Motorcraft and forget about it. I'll have to dig pretty deep as they cost $15, but maybe that is why they work well. LOL....

I replaced the thermostat last year because it was set up with a thermostat that is designed to be partially open at a minimum and with NO bypass hose around the thermostat. I had purchased my Cobra from a very hot climate (Florida) and it was set for max cooling all the time. Roush advises to always use a thermostat bypass. I set it up with a bypass hose and a fail-safe thermostat.

Again, thanks for the good info!

bingo2 · #17 (**permalink**) 06-02-2011, 06:54 AM

Quote:

Originally Posted by Frank Messina

Some time back I tested several brands of thermostats and the Motorcraft were the only ones that opened at the stated temp.
Frank

I wanted to remove the 160 thermo that came in the car when I purchased it and bought a Mr. Gasket (MotorRad) 180. I tested it last night and it opened at 192.6 according to my digital thermometer. I think I'll take a trip to the Ford dealer today.

WardL · #18 (**permalink**) 06-02-2011, 06:58 PM

Bingo2: Apparently you can't find a Motorcraft 180 F thermostat in Washington State! Ford said they could order one from Oregon. I couldn't find a "normal" 180 thermostat today. Tomorrow I hope to buy a 190 F Motorcraft thermostat at Ford. I'd be curious if you found a Motorcraft 180 F today. I need it this weekend so I'll go with the hotter one as suggested by Frank. I've been saying I need a thermostat for a 1995 F-150 5.8L 351 Windsor engine. Does that engine have a 180 F thermostat?

bingo2 · #19 (**permalink**) 06-03-2011, 10:19 AM

Ward...perhaps not in CA either. The dealer had 192 and 197 and the parts guy said he wasn't certain there is a 180 available.

DAVID GAGNARD · #20 (**permalink**) 06-03-2011, 10:25 AM

Quote:

Originally Posted by bingo2

Ward...perhaps not in CA either. The dealer had 192 and 197 and the parts guy said he wasn't certain there is a 180 available.

I'm thinking the later models, say 90 and up had 192 degree thermostats, one could ask for a thermostat for a early to mid 80's F-150 with a 302/351-W and see what it calls for and what they have on the shelf.....

I know the later model GT Mustangs had 192 thermos in them.....

David