Is it possible to have a fualty new thermostat

[doobiess]

Well i just replaced my thermostat about a week ago and nothing but problems.. and today I had the temp go into the red... and half way through ...no heat came through the vents... pulled over shut off the engine.. and waited a bit.... and fired the car up.. and it climbed up again.. no heat from vent.. then before i knew it.. the thermo opened... temp went way down and blast of heat out of the vents.... once after being cold.. and having it heat waaaay up and opening it will work ok.. but just.. it maintains the temp of the car at 220 and just....

My dad says thermo's can be faulty from the box.. and well i have all new anti freeze with no air loc's. New rad from last year and new water pump from 2 months ago.. new rad hoses... and just had the system flushed last week..

But has anyone had the prob of having a faulty thermo from the box or know anyone have that happen to anyone??

[zaphod617]

You can get a bad unit out of the box.

You sure you've got it in right? If it's backwards the thermostat won't open.

[doobiess]

on the 3100 v6 model it only goes one way.. and if it were it wouldnt work at all but mine does only after it heats way up

[NewNann]

I've heard of Stant thermostats being bad right out of the box. What brand are you using?

[4kQuad]

Great joy...pull the stat, take it in the house and put it in a pan of boiling water. if it don't open...it's bad.

I have had a bad one right out of the box before, but that was 24 or so years ago. I would drop it in as the water first starts to boil.
That way it would be "close" to the same temp as it would open in the car.

if you drop it in rolling boiling water...your not testing at the temp your car might get to.

[doobiess]

ok thanks guys gonna get a new one today and install it and test my old one... (and new one)

[stockert]

Let us know what you find out!

[4kQuad]

Did it open???

[babygurl2000]

yep you can get them bad right outta the box.
they are cheap.

i always check mine with the boiling water thing before i install it

[rixGAphx]

Originally posted by babygurl2000
i always check mine with the boiling water thing before i install it
And as you prolly know, Julie, you can check the EXACT temperature of opening by putting a candy thermometer in the water.
* * *

BTW, most t-stats have a thin molded-on rubber seal around the closing disc.

If the engine ever boils-over and looses coolant, the t'stat can become high and dry within the system.
The intense heat transferring thru the metal can melt this rubber seal.
The melted rubber can either:
* Act like glue-gun adhesive, thereby 'gluing' the closing disc shut; or,
* Develop irregularites that kinda 'grip' the sides of the opening, so the t'stat doesn't open smoothly. Rather, the temp must get REALLY hot for the t'stat spring to produce enough force to open the disc.
* * *

-Rick

[doobiess]

ok well here is the update.. first off i put a pot of water on the stove at max and it wouldnt open.... used a thermo.. and the water only reached 180 degrees so it wasnt hot enough... anyways... replaced the thermo.. and the initial warm up went fairly warm assuming due to the air pocket inside where the thermo was... and now it opens just before the midle mark.. and every time.. only thing is im having a tought time getting all the air out....

this is what im doing

Just got home from work and engine is full temp.. i open the bleeder valve just a bit until i hear hisssing.. from air and coolant coming out.. i do this until just straight coolant comes out.. and do this only when there is pressure in the system...
Then i wait until the engine cools and open the resivior and check level.. first time i did this the water went in the engine and could hear a * glug* sound... and did this 2 times... by this afternoon i check the coolant level and it was low... so topped it up.. and repeated ... but i only open the bleeder under pressure so the coolant and air will come out.. but leaving the rad cap on so im only removing remaining air... and leaving it closed to not let anymore in... and open the resivior when its cold since the coolant will only pull itself into the engine due to the little bit of suction that i should of created by removing that bit of air from the bleeder..

Reason i know its still got air... when driving it runs 100% at idle it goes up... like its not flowing and will only flow when throttle is applied...

Other wise all is good and thanks for all the responses..

[babygurl2000]

yep i had issues with my 94 Z26 Beretta just like you are having and it was the heater core not the thermostat at all.

if your cooling system is plugged with calcium buildup and stuff it needs to be flushed out or if you have the slightest pinhole in a hose somewhere or your radiator it wont work right either.

[rixGAphx]

Doobiess:

Your description of your bleed procedure, and your rationale for it, is the exact CAUSE of your trapped air and resultant problems.

NEVER OPEN A PRESSURIZED COOLANT SYSTEM!!!!

PERIOD!!!!

Not at the reservoir cap, not at a hose, NOT AT THE BLEEDER. :geez:
* * *

The procedure is VERY simple:
1. Allow system to cool to normal temperature (20*F outside in BC, 50*F garage, 70*F outside in Phoenix this afternoon ( :D :D).

2. Open the reservoir and set cap aside.

3. Using two wrenches, loosen the bleeder screw.

4. Fill reservoir to THE FILL LINE (about 1.25" below the filler neck) with coolant.

5. The inside of the radiator and the inside of the engine will fill BY GRAVITY, as the liquid finds its own level.

6. Trapped air WILL escape thru the bleeder, as the gravity-seeking liquid rises and forces it up.
It doesn't need the 'pressure of internal heat' to force the air out.

7. When the smallest trickle of coolant dribbles from the bleeder screw, the system is full.
Close the bleeder screw and reinstall the reservir cap.

You're done. System full and bled.

Start engine, run up to operating temp, and allow to cool-down fully.

REPEAT THE BLEED PROCEDURE ONCE!
A LITTLE air might have still been trapped in the radiator and/or heater core during the first bleed.
Most of this air would have been harmlessly released into the reservoir, but a few cubic inches will have risen inside the engine.
The second bleed will remove even this air.

Your bleed procedure theory had some good points, but it was actually CAUSING trapped air (and prolly damaged the t'stat to boot).

Good luck.
-Rick

[doobiess]

ok i see that point but the bleeder screw is not the highest point in the cooling system.. the resivior actually has a higher point but the hose that goes from the top of the water pump .. up and over the valve cover is the highest point and there is an air pocket..

My dad is an auto mechanic which owns a 89 mustang and my boss at work has an 94 aerostar .. my dad asked about both vehicles and the prob with them is the heater core is the highest point in thier system.. and ever since my dad drained his cooling system due to water pump change his heater core is non existant.. He asked his friend at the local ford dealership and he said yes all aerostars 3.0L and the 5.0L stangs(very similar cooling setup) need a special maching that will pump all the air out of the system.. so from no on hes left with no heat..

Reason i say i have trapped air is...

running at 50 kph or 35 mph its sitting at 1/3 temp... on the highway its higher just below the half.. but after driving and stuck in gridlock traffic my temp climbs and climbs past the half way point.. well beyond the point of the thermostat opening and it will remain hot or get hotter until i just put the car in neutral and the temp drops immediatly..
Reason i say air is on the 3.1 thermo is high on the engine.. and the thermostat housing goes up higher and then back down and connects to the rad hose.. causing another air pocket.. so bassically temp reading is false.. and so being the car cant maintain the cooling unless the water pump is spinning more to flow more..

BTW new water pump as of Nov. new rad as of Aug... new rad hoses..new temp sending unit.. new thermo as of 3 days ago.. and new coolant after a complete system flush.

[rixGAphx]

A new guy over in 'Old Guys' mentioned a bleeder in the T'stat Housing.
I never knew about that, mebbe try bleeding there, too.

Hell, drill holes and install bleeders wherever you feel is high and they need to be. I dunno.

JUST BLEED THE SYSTEM WHEN COLD.

If you bleed when hot, you are guaranteeing that air will enter as the coolant cools/contracts.
* * *

It is often helpful to understand how other vehicles/manufacturers engineered to solve similar (or identical) problems/conditions.

But it's a real mistake to *assume* that a Ford procedure/solution bears any resemblence to that of Pontiac or Porsche or Peugeot.

-Rick

[Quantum]

Where's the bleeder screw located that you are talking about rixGAphx?

Regards,

[Pushn_Fords]

My wife has a '94 GT with the 3.1L that I've worked on for 5+ years. I've put in a radiator, water pump, heater core, intake gaskets, and hoses at different times. When I first started working on it I always opened the bleeder screw when the engine was hot. I had been told that the pressure would force the air out.

After changing the intake gaskets recently that procedure just wasn't doing it. I talked to a GM tech friend and he said to bleed the system cold. So I took the bleeder screw out and poured antifreeze in the reservoir until it came out of the bleeder hole. As it was pouring out I put the plug back in. I ended up having to do that 3-4 times during the next week to get all of the air out and the temp is finally staying down.

Hope you figure it out,

Derek

[doobiess]

ya so as for a week later ive been driving a fair amount and keeping an eye on the car... So far on the highway in hills and mountian driving.. the temp will maintain itself but just... at the halfway mark... doing about 80-90kph or so and at cruising no hills at same speed is slightly lower.. but on level ground driving easy will be alot lower temp.... but the thermostat is working perfect.. just gonna wait a bit

actually in the next few weeks im looking to head to the local ski hill which is a 3000 ft climb in 18kms so its pretty steep so that is why im trying to make sure it will be ok for the trip..
PS the mountain is 3 1/2 hours out of town.. so breaking down out there would be COSTLY