Car not warming up

[Clement]

'87 Pontiac Bonneville, 3.8L v-6, 119K miles on the car.

Brand spanking new thermostat (195 deg), The temp gauge will raise up to mid point (180 deg) then immediately drop off to 100 deg. In normal running it doesn't get above 140 deg. I know the gauge is reading correct, because the heater never puts out hot air. It'll get a little warm, but never hot.

This is the second thermostat I've tried that has done the same thing.

The thermostat is placed in the engine block with the spring inside the block. The rubber o-ring gasket is then placed on top of the thermostat, and the hose is then tightened over it.

Is this correct? Am I putting the thermostat in backwards?

I even covered the radiator with cardboard, about half of the radiator covered up, and it showed no difference in temperature or behavior.

Help me figure this out. It's too **** cold to be driving around without heat.

 

[T-Keith]

The thermosta needs a rubber gasket that goes AROUND it not on top. The o-ring is for the hose neck.

Hope this helps. It sounds like you have the orientation correct.

 

[Clement]

So they gave me the wrong gasket!

I'll print the picture out and see if I can get it this afternoon.

Thanks!

Where did you get your gasket? I just looked at Autozone, Advance auto parts and Napa's websites, and they only carry the o-ring gasket for this car.

[ January 21, 2005, 10:13 AM: Message edited by: Clement ]

 

[oldman]

T-Keith-nice pictures

 

[Marlin]

Actually it is supposed to be a O-Ring. There is more then 1 type of gasket/o-ring/etc... to work on thermostats depending on the car.

How old is the Rad. cap? A bad cap can cause a low/no heat problem. Also are you losing any coolant?

 

[Clement]

Brand new radiator cap, the old one had a shot gasket and was causing fluid loss. No fluid loss with the new cap.

The radiator gets warm, but not hot. On my Hyundai when the motor is at operating temp, the hoses and radiator are too hot to touch. That is not the case with this Pontiac.

 

[T-Keith]

The gasket is really hard to find. A Checker they old had the o-ring for the neck. On my 88 it was a similar story on that there are two o-rings on the neck and they could only get one. Why I don't know?

The gasket in the top is actually not the correct one, it is one I found at checker that works OK. I believe Autozone didn't have the correct one either.

-T

 

[jsharp]

I can't picture the car, but does it have an electric fan that's for some reason running all the time? Or a clutch fan that has a frozen clutch?

 

[doitmyself]

My .02 cents:

People often talk about air pockets developing after coolant system work. The pocket prevents proper circulation of the coolant. Does this really happen?

Does running the engine with the cap off for awhile cure the problem?

I have seen mechanics test a thermostat by holding it with pliars, then gently heating it with a propane torch to see that it opens, then closes COMPLETELY as it cools.

Your water pump is o.k.?

 

[T-Keith]

quote:

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Originally posted by jsharp:
I can't picture the car, but does it have an electric fan that's for some reason running all the time? Or a clutch fan that has a frozen clutch?

---

Electric fan.

 

[punisher]

doitmyself
Member # 51
"People often talk about air pockets developing after coolant system work. The pocket prevents proper circulation of the coolant. Does this really happen?"

Oh yes. 3.8L FWD Fords we would often have to put the front end on the lift and pick it up 4 ft to "burp" air pockets.

3.8 RWD engines were equipped with a 13mm plug to remove to let air out of the cooling system, all 4.6 4Vs as well had a bleed plug.

Few things worse than slamming headgaskets on a Ford 3.8 then letting your helper fill it with coolant and forget to remove the bleed plug.

 

[jsharp]

quote:

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Originally posted by T-Keith:

quote:

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Originally posted by jsharp:
I can't picture the car, but does it have an electric fan that's for some reason running all the time? Or a clutch fan that has a frozen clutch?

---

Electric fan.

---

The reason I asked is that we had that problem with my sons "new" '93 Pathfinder. The fan clutch was frozen when we bought it and it didn't want to get warm and stay there in the 5 hour drive home.

That vehicle also has a bleed port on the top radiator hose and if you don't bleed it after a coolant change it will cause problems.

I'll be interested to see what the original poster finds solves his problem...

 

[T-Keith]

quote:

---

Originally posted by punisher:
doitmyself
Member # 51
"People often talk about air pockets developing after coolant system work. The pocket prevents proper circulation of the coolant. Does this really happen?"

Oh yes. 3.8L FWD Fords we would often have to put the front end on the lift and pick it up 4 ft to "burp" air pockets.

3.8 RWD engines were equipped with a 13mm plug to remove to let air out of the cooling system, all 4.6 4Vs as well had a bleed plug.

Few things worse than slamming headgaskets on a Ford 3.8 then letting your helper fill it with coolant and forget to remove the bleed plug.

---

The 86-87 FWD don't appear to have a good way to bleed air, which leads me to believe that it is designed to not need bleeding. Perhaps it's because the top radiator hose is pretty much the high point on the system.

My 97 L67 has a bleeder screw on the top radiator hose neck, but the TB is also higher then on the 86/87 engines.

 

[ZR2RANDO]

Usually I have noticed cool running conditions to be caused by thermostats that are either stuck open all the time or just open at lower than correct temperatures. It will cause coolant to run through the radiator and engine without ever building up to proper temp during the winter, and can also cause a hotter than normal temp in summer because coolant doesn't spend enough time in the radiator to cool off as well.

Have you started the car cold and watch through the radiator cap opening to see when coolant starts moving through the radiator? When it starts moving check it with a stem thermometer to see what temp the thermostat is opening at. Make sure the overflow tank is full so when the cap is closed the expansion will actually go into the tank and then pull some coolant back in when it cools off, that will gradually get the air out of the system hopefully. Parking on a hill with the radiator up is a good idea as stated above too!

 

[Mike_dup1]

quote:

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I even covered the radiator with cardboard, about half of the radiator covered up, and it showed no difference in temperature or behavior.

---

This is strange. It should run hotter with the radiator blocked off. Did you check to make sure the fan is not running constantly, as was suggested? Fan should not come on untill engine gets hot, if its running and the engine is cold, you found problem.

Also things to consider.

Are the stat's you are using the 195° versions? Or are using using a lower heat range? 180° etc? Don't that, it confuses all the sensors.

Another thing, make sure you are getting a good brand name part. Lots of cheap junk out there. Maybe try AC Delco next time.

[ January 24, 2005, 09:25 AM: Message edited by: Mike ]

 

[Clement]

Here is what I did.
I made a gasket for the thermostat out of some waterproof silicone gasket sealant material on the spare 195 deg thermostat I had and allowed it to dry). When I pulled the hose to change the thermostat, after the car was driven by my wife, the coolant was under pressure, and the t'stat valve was open. It closed shortly after removing from the car (it was about 10deg outside). So the coolant was at the correct temperature!
Put the 'gasketed' t'stat in the car, topped off the fluid, drove around a bit, same thing, temp might peak at 180 or so, and immediately drop down to between 100 and 140 deg and then stay there. Put more cardboard over the radiator, about 80-90% covered, same thing.

Could it be that the heating coil is clogged and the actual temp gauge is screwey?

The fan does not run when the motor is running.

I was wondering if a full on flush would help this out?

 

[Ugly3]

Try this: completely cover the radiator with cardboard and let the engine idle. Feel the upper heater hose (carefully), you will be able to tell when the engine is getting really hot. Go see what the temp guage indicates. Should tell you if the guage is correct.

Good luck.

 

[ZR2RANDO]

Still sounds like the t-stat is opening early, and then is allowing coolant to continue cycling due to low opening temp...have you verified the 195 t-stat is really opening at 195? You can also check it in a pot of water heating/warming on a stove..

 

[MolaKule]

quote:

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"People often talk about air pockets developing after coolant system work. The pocket prevents proper circulation of the coolant. Does this really happen?"

---

Yep, happened on my daughter's Explorer after replacing radiator and heater hoses.

No hot air from heater. Lifted the radiator cap while engine was running and "Blurp, blurp." Now had hot air. I had to replace fluid as well since bubble(s) burped out some of the fluid.

I had to let engine really warm up (with cap off) in order get all bubbles out of system.

 

[kenw]

quote:

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Originally posted by MolaKule:

quote:

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"People often talk about air pockets developing after coolant system work. The pocket prevents proper circulation of the coolant. Does this really happen?"

---

Yep, happened on my daughter's Explorer after replacing radiator and heater hoses.

No hot air from heater. Lifted the radiator cap while engine was running and "Blurp, blurp." Now had hot air. I had to replace fluid as well since bubble(s) burped out some of the fluid.

I had to let engine really warm up (with cap off) in order get all bubbles out of system.

---

sounds to me like the rad cap wasn't working right. It should have "self-burped" so to speak and let the air go into the overflow bottle. It can sometimes take a few days. but the t-stat has to open for this to happen in most cars.