ok. i need help... i have been trying to figure this thing out for a lil while now.. id ont get any heat in my car.. jsut warm air form engine.. which really isnt enough. i have checked all vaccuum lines. they are ok. except water valve vacuum switch.. which has been bypassed but i can put right. i DID put a new heater core in it. i do have flow thru heater core. so why no heat? would jsut the water valve vacuum switch make it not work? blower does work (in only one position.. but it does work.) help me out please.... also would a vacuum leak in this area cause my car to run really rough?? ok im off to bed but i hope ya'll can help.
I would think it is your thermostat cause my maverick have a low temp thermostat I think it is 150 or 160 degree thermostat which keep the engine nice and cool. But when I turn on the heat since the engine running so cool it only blows warm air out the vents. So do you know what temp your thermostat is working on?
How is this bypassed? If the heater hose still goes through it, it can be your problem. I would remove it all together. Next would be your vacuum problem. Since all the controls in the heater box are run by vacuum, there is probably a door or something that is not opening to direct the air where it should go. Does the air blow out of the vents or at the floor? Usually when your vacuum system stops workin, air only comes out the defroster vent.
Are you sure about this? My 77 without a/c has no vacuum controls on the heater, just 2 cables controlling the air output. I think only the a/c cars had the water vacuum valve. How do you know you have flow through the new heater core? I have had cars where someone plugged up the heater hose with a steel rod because the core leaked.
I was refering directly to Syklops75 and his car, which I assumed has factory air because of his description in his post. You are correct, non factory air cars do not use vacuum controls.
to answer a few questions.. 1.no valve on hose lines.. jsut straight to heater core now... still only warm air. 2. have no clue boutt he thermostat.. never needed to check it 3. vacuum wasnt hooked up to the heat when i got the car. was capped off and some lines missing. ( i think this is where it may be the problem) when i hooked up some vacuum to the system.. the vents will blow where they are supposed to for the most part. (loose vent or two) 4. does have factory ac.. 5. i did some searching of previous threads and found a link to what the vacuum lines are supposed to be.. am gonna check that.. but no to sure bout if its the right system. some pieces on the diagram that i apparently dont have. p.s. driving the celica for heat now.... i miss my mav... p.s.s if i didnt hook the vacuum up right or hooked it up without the vacuum resevoir will that make it run rough???
hey my mav did the same thing water pump was leakin a bit changed the thermastat which is easy and i got a little bit of heat turned out it was all those things and the heater core which is a bit of a pain but pretty easy i just followed my repair manual
i have a new heater core in it now.. still only lukewarm air.. i guess only thing left to try is replacing thermostat with higher temp one. thats the only thing i thinki have left. but first i gotta figure out why the car wont stay running now.... i love my car but sometimes i wanna shoot it.
phil, with the car warmed up, turn the heater on..then take hold of the heater hoses and see how hot they are. if you can hold them it could be the t stat. if they are too hot to hold then it is one of the heater box doors not opening...jmo...frank...
hey man have fun i now have a totally new maverick because i changed everything and when i mean everything i mean everything carb.rad,rad hoses voltage regulator,ignition switch ball joints shocks ,idler arm heatercore,fuel pump,water pump all battery cables .now with your car not staying running that could be your carb set up mess with the two screws on the drivers side of the carb till you get a good idle and set your choke. does your car have an anti desiel switch which is located on the passenger side when you remove the filter off the top its a little screw its easy to set with that. if all else fails take it off and make sure it is clean and replace the fuel filter its amazing how much it helps .now i know nothing about cars till i got my mav and i did all the work with the help of all the guys on this site they are great and someone usually has had the same problem my car runs awsome now
the running part is the carbueretor... got it running but gonna need a new carb. as for the heat.... only thing left i havent replaced is thermostat... i CAN hold the heater hoses with my hands.
When the car is up to temp, stick a thermometer in the radiator and see what the actual temp is. My Dad had a 65 Galaxie 500 2 dr hardtop LTD that after about 150,000 miles, had so little compression, it wouldnt get warm at all. Had to totally block all air flow to the radiator in the winter to get any heat out of it. The thing was hard to start too because of the low compression, but it still ran great once it got going. I remember the last winter that I lived at home, he would just leave it running all night long on the really cold nights. Of course gas was .21 a gallon back then. It was a beautiful car and its the car I learned to drive in. Sorry to say he eventually moved to FL and traded it in on a pinto.
didnt know low compression would do that. interesting.. gonna try the thermostat first tho.. hoping thatll be it.... traded on a pinto??? ouch...
