Alrighty V6ers I got your attention.Now put your thinking caps on and please help me with my delima.I live in Georgia and it is currently 29 degrees Farenheit(sp?)It has been in the lower 20s the last few nights or so.Now for the reason for this thread.My 91 V6 MPFI Firebird has a problem that I have been putting up with the last 2 years or so.It don't matter if I drive 1 mile or 100 miles I just can not seem to get my heater hot.My defrost and my heater just seems to be blowing out semi warm heat.What in the world could be the problem.Is it the thermostat?or possibly something else?Thanks in advance guys,yall are the best

 

As you can tell by my car pics I need a good heater...lol.

So first I would replace the Thermostate, and see what that does, its like $15 to do, and it won't hurt anything.

But I think your problem lives in the heater core...YIKES...
Have you ever used Radiator stop leak?
Its great stuff but they forget to tell you that it plugs up your heater core, and then you lose your heater...

If the thermostate doesn't fix it its more than likey your heater core, and the heatercore lives inside the dash, so it will be a several hour job. Well after you replace thermostate post again on results, then I will have a bit more to say...

 

There is a divertor valve for the heater core, check that. sometimes there broke. Air pocket in the heater core will also screw with ya.

 

do all "Radiator stop leak" type products clog the core?

 

As far as I know it does not have any stop leak in it,at least I haven't put any in it myself.Check this it out....went to my sisters house to help her move,while I was getting ready to leave tonight I went ahead and warmed up my car a bit before I left,currently 30 here now,anyways,I let her idle about 10 minutes or so and when I jumped in it,it was like a durn oven!!but on my way home,about 5 miles down the road or so the engine temp dropped and so did my heat from my heater,from very hot to warm.Its like the cooler my engine got the colder my heater got.Whats up with all of this,I'm tired of seeing my breath inside my car...what can this be????

 

Sounds like your running without a thermostat. When you say after the engine cooled down, how cool does it get?

 

Some say they won't but if you use enought of it it still will Stop leaks is meant to be used in small amounts, its a quick fix for a little while, its when someone over uses it it cause problems. Just think about it, a gooey substance to stop leaks running through your very tiny heater core...lol



Yup that last message you gave sounded like the Thermostate, which is great cause you really did not want to mess with the heater core... So go buy a new one, stick her in and tell us how it works.

 

id bet that your thermostat was stuck wide open, unloged itself (you got heat) then once the engine temp went up enough to open the thermostat again it stuck in that position

(just my opinion

 

A freinds experiance with stop leak. Water pump was leaking a little.($85) Decided to go stop leak($8). A month down the road the heater core explodes(Clogged)($175). 2 more weeks the Radiator goes out(Clogged, No amount of flushing worked)($200) Now add the thermostat, various hoses, and valves approx($175) thats a $hit load of money to have wasted to just replace a $85 Water Pump!.($543 Approx)

Now the no heat prob. There is a valve on the passenger side right behside the air pump. It has a Vacuum line attached to it. Pull it off. This opens that valve completely to allow coolant to flow to the heater core. That Valve is a $100 plus piece of dealer plastic. My heat works great. Thats a free thing to try. If that still does not work do the thermostat thing. Go 180. You have heat in the winter time and it allows your engine to get out of full enrichment mode while driving(the 160 won't).

 

I agree with all the "thermostat" guys... sounds like yours is stuck open. It can't be the heater diverter valve; otherwise, you wouldn't have gotten heat while the car was idling. And if it's heat you're after, go for the stock 195 for the winter.

 

I have received alot of useful information,THANKS GUYS I will be on my way to get a new thermostat hopefully later on today.Which one should I buy?180,160,195,so that the engine pretty much runs at a good temp(no loss of power please,I have a V6,I need all I can get )yet I will end up with some comfortable heat during the cold season here in Georgia.As far as my engine temp while driving around here while its cold,its stays right around the little line past the 100 and as far as changing the thermostat on a scale from 1-10 how hard would it be to fix myself?Sure would be awesome if someone could maybe give me a run down on the entire change out process.Thanks again guys for all your help.This is truly the BEST site on the web!( I am currently puting on my shoes getting ready to go to AUTOZONE,now which one to buy...HMMMMMMMMM)

 

When you get your thermostat out....try this little experiment to find out if you have solved the problem.....boil the thermostat on the stove. Thermostats work by heating up the spring, causing it to contract and pull open the damper door. One the water has been boiling for a minute or two, pull out the thermostat and see if the damper is open...if it is still closed, you probably will need to do more then just replace the thermostat.

 

GET THE SAME ONE AS YOU HAVE STOCK. If you mess with different ones you engine sensors will not get the correct reading ect. If you car is running at 220 your ECM needs to know that, and buying a cooler or hotter thermo could screw that all up. All you need to do is:

1) Drain the radiator (you may not have to but it won't hurt anything to do so and put new coolant in.
2) undo the top hose from radiator to intake, undo those bolts.
3) There she is! Make sure you put it in the exact same way as the old one was.
Then reverse 1-3.

Hope that helps. Trust me, you can do it.

 

Haven't had a chance to replace my thermostat just right yet,currently making plans to go pick up my "FREE" V8 Camaro! I recently started a thread under the restoration topic.Anways,So do I really just need to stay with the stock temp? Just go to the auto parts counter,tell them my make/model and they will give me my stock one?Thanks for all the awesome feedback guys You all are the BEST Thanks again!!!

 

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