No Heat

[96RS Alex]

I can't figure out why I do not have heat blowing through any vent in my '91 3.1 Firebird. I activated the defroster and noticed it for the 1st time. The switches for vents and temperature above the radio console work great with no problems. I am trying to prevent regular condensation and foggy build up from cold, raw mornings and evenings everytime using my defroster. I can hear the vents open & shut and air is properly deflected out when selected.

I have done the following since early summer 2005:
~Heater core
~Waterpump
~170* Thermostat
~Hoses ( all )
~Radiator ( flushed of sediment, original stock )

I had many overheating issues before and resolved them for the summer so there was no reason for me to test the heater for the heck of it but now I need it.

The brand coolant mix I am using is Prestone 50/50. 100% of the coolant is circulating throughout the motor.

Should I switch back to the stock 195* thermostat?

Cruising around on normal sunny days it's still pegged @ 170* and goes a tad higher while idling in traffic.

[3.4 slow to go]

check out your divertor valve (if you have one. not sure on those later yrs)

[Jerriko]

Yes, switch back to the 195 thermostat. I noticed the same thing on my car when it got cold outside. Also, make sure you don't have any air trapped in the cooling system. Hot air in the heater core will keep you cold and frosty all winter all.

This is for everyone. Whenever you do any type of work to the cooling system, you always check the heat regardless of the season. Whether you have heat or not is the number one telltale if you did the work right or wrong.

[96RS Alex]

The Diverter Valve was another item I replaced along with the new hoses I forgot to mention but a good call on your part 3.4!

As far as the thermostat goes, I will change that part this weekend. Fall is here.

I squeezed the top & lower hoses to burp any air out when I tested the new waterpump way back when. Today, I uncapped the radiator on a cold motor and it was surely topped off before I started it.

Is there a particular way to bleed any air out of the 3rd Gen cooling system? There is no bleed screw like the 4th Gens.

[3.4 slow to go]

the home way:
put the front end up on jacks, but preferrably ramps, as high as possible & run w/the rad cap off.

better:
take to rad shop & have them do it.

[96RS Alex]

I get it now, interesting way to bleed the air off.
I will post my results by the end of this weekend.

[96RS Alex]

UPDATE:
Finally got around to resolve this no heat issue. It turned out to be Prestones 50/50 pre-mixed formula. I guess the formula is great for summer conditions.

I dumped that coolant and tried a 70/30 mix of regular Prestone with distilled water and the heat returned after roadtesting. I noticed a slight increase in power too. Engine seemed to be happy running near the 200 degree mark. The heat could be a bit more warmer but I'll give it more time.

Now I question an 80/20 mix of Prestone & distilled water for extreme cold conditions, is this recommended? I am expecting a brutal winter arriving into the Northeast and looking for heat that will dry out your eyes like most Fords are infamous for ;) .

[ November 21, 2005, 11:31 PM: Message edited by: 96RS Alex ]

[3.4 slow to go]

congrats!!!!!

personally, I'd stay w/teh 70/30, as the water will allow it to heat up a bit more.

switch to the stock temp thermostat for the winter months.

****** Distilled Water ******

good on you mate [img]graemlins/banana.gif[/img] [img]graemlins/banana.gif[/img]

[Jerriko]

Originally posted by 96RS Alex:
UPDATE:
Finally got around to resolve this no heat issue. It turned out to be Prestones 50/50 pre-mixed formula. I guess the formula is great for summer conditions.

I hate to burst your bubble here but there is no way that the coolant could be responsible for you not having heat. When you changed the coolant, you must have inadvertently changed something else, probably something you didn't notice. If you run pure water, pure antifreeze or any mixture regardless of age under a pressurized system, you will have heat. The coolant transfers heat from the engine to the heater core. You could fill the coolant system with oil and it will still transfer heat. Guess off the top of my head is that when you changed out the coolant, you got rid of the air pocket in the system that was causing the problem. Either way, I am glad you fixed the car.

[3.4 slow to go]

a lower than norm thermostat along w/too much coolant could (well, not as much heat as used to)and alsoaffect drivability.

some good q & a links

http://www.peakantifreeze.com/faq.html#A

http://www.eetcorp.com/antifreeze/antifreeze-about.htm

http://www.phmeters.com/New_Folder/a...ation_note.htm

[96RS Alex]

This is all good info & I fully understood the cooling aspects of the 3.1 engine, I appreciate the feedback too.
I just about replaced everything I can think of to bring back heat but the comments about any air pockets in the system stood out and that may have been the culprit originally.

Keeping my fingers crossed on this 264,400 mile Firebird!

[ November 23, 2005, 02:25 PM: Message edited by: 96RS Alex ]

[rhodeymark]

I am expecting a brutal winter arriving into the Northeast

I reject that statement! After the $h!t we had last year I demand a mild winter
[img]graemlins/rant.gif[/img]

[Turbo V6 Camaro]

i had heat prblem in my 2.8 1989

and so did my friend in his 1990 3.1

we took some card board and blocked off 25% of the radatior and got some back..... then we did 50% and the car never over heated and i always had heat....

and if for some reason the car would start to get hot...... we tested and pull it out and last heat in about 5-10 mins lol

took all of 1 minute to pull it out if we needed too

[3.4 slow to go]

thecardboard thing is what many do in northern tier bases, such Minot, ND (been there, done that. But for this case, it would be a bandaid that would be hard to remove @ 70 on the hiway.

[96RS Alex]

NO HEAT AGAIN

As I mentioned before, the heat could've been better but it's still not to my liking.

I have to ask, what does this line do that's attatched on top of the diverter valve? http://putfile.com/pic.php?pic=1/523402687.jpg&s=x11
Must be a vacuum line...? (Yes that is my Sharpie pen pointing to the subject in question)

The small hoses that route from the waterpump and intake manifold by the thermostat all lead into the diverter valve were hot but the inlets coming from the heater core that connect to the valve were sorta cool to the touch after a hard drive. This is a brand new diverter valve twice now fyi.
I am tempted to fabricate some kind of plumbing using tee valves and 5/8 to 3/4 inch hoses and avoiding this middleman part but I need opinions first. Thanks again!

[ January 07, 2006, 01:57 AM: Message edited by: 96RS Alex ]