Author Topic: Lack of heat (Read 4324 times)

sethyboy85 · « **on:** November 28, 2005, 06:51:15 pm »

when it's 20F outside my car doesn't make enough heat, when its 50F I can burn myself from the air coming out.

heater hoses are nice and hot, flushed the system 1-2months ago... only thing I can think of is 1. too much air is coming in from outside into my ducts or 2. I have junk in my heater core and need to flush that individualy...

Is there a way to block some of the outside air from coming in through the ducts though?

vwmike · « **Reply #1 on:** November 28, 2005, 06:56:08 pm »

How high is your coolant temp on the gauge? I actually had plenty of heat up until a few weeks ago when it started taking a long time for the car to heat up and the gauge barely ever got off the minimum mark. A new thermostat brought the operating temperature back where it should be and the heat works much better. The thermostat had been stuck open for a long time and it had to be cold enough out for me to notice it.

sethyboy85 · « **Reply #2 on:** November 28, 2005, 07:14:16 pm »

half or above half when climbing hills...

vwmike · « **Reply #3 on:** November 28, 2005, 07:17:22 pm »

I'm going to guess the heater core might be clogged then.

sethyboy85 · « **Reply #4 on:** November 28, 2005, 07:24:12 pm »

both hoses are piping hot after running the car, but I will get out the garden hose disconnect both sides from the rest of the system and blast away.

QuickTD · « **Reply #5 on:** November 28, 2005, 07:26:50 pm »

I had a serious lack of heat ever since bought my car. Engine temp was always 90ºC, I flushed the heater core, nothing worked. I finally ripped the dash apart and found a screw lodged behind the blend door preventing it from closing. I shook the heater box upside down to remove the screw, reassembled it and I now have killer heat.

I've also heard that the foam rubber covering on the blend door can disintegrate and allow cold air to bypass the heater core, worth checking...

sethyboy85 · « **Reply #6 on:** November 28, 2005, 07:53:36 pm »

I have foam blow out of the vents everyonce and awhile...

sethyboy85 · « **Reply #7 on:** December 15, 2005, 11:42:56 pm »

so can the blend door be accessed without taking the dash out?

I am really freezing lately...

QuickTD · « **Reply #8 on:** December 17, 2005, 12:16:05 am »

Search the vortex for "no heat" or "poor heat" and you should find some stuff. I believe the foam can be fixed without pulling the heater box if you have the hands and skills of a gynecologist...

rabbitman · « **Reply #9 on:** January 21, 2008, 04:39:44 pm »

My rabbit has a miserable heater so I put in a auxiliary heater with tees in the heater core hoses and it gets hot now, I don't know why but it also blows heat way before the stock heater even thinks of makin' any heat. I also have a new heater core and I bypassed the valve. It made me mad to have to put in a ugly heater but I got sick of freezing. I hope yours isn't as hopeless as mine.

jasonsansfleece · « **Reply #10 on:** January 21, 2008, 06:57:30 pm »

Check the blend door. Easy job on my 85 Golf. No need to take out dash.
Remove center console. Drop plastic panel that runs along the under side of dash. Remove center air vent, pry the little louvered bits from the side and then out, to reveal the screws that hold the vent unit in.

You now have the front of the heater to take off, vertical rectangular plastic held on with five or six screws. Undo screws and pull out the front and in doing so you will observe through the center air vent how the front is connected to the side vents. Might take some wiggling to disconnect.

Now you can see into the heater and if you move the heat control on the dash you will see a metal door move. This door has several holes that should be covered in foam. If they are not, then there's your problem.

Obtain some good quality foil-backed duct tape (don't use the regular kind, it will fall off after a while.) Installation will be much easier if the tape has a paper backing strip covering the adhesive. Cut a strip the correct length, go ahead and measure it. Practice placing the tape in place. Peel back an inch or so of the backing paper, place the tape on the door, gently tacking in place the exposed adhesive. Check it's in the right place then pull back the remainder of the paper backer and stick the tape to the door.

This might seem quite the procedure but you are working with your fingertips deep into the heater box. The above technique worked for me.

rabbitman · « **Reply #11 on:** January 21, 2008, 09:17:48 pm »

Well, see the problem is that my heater box is out of a 77-80 rabbit, so
there isn't a blend door. All of the air enters the car through the heater
core and you shut the heat off w/ a valve in the heater core inlet hose. So
the flaps in the heater box only direct air to the windshield and/or the feet area. I got the car out of a junkyard so I don't now all that was done to it. Also, the dash has vents below the radio, but there wasn't a duct to it, and there wasn't a spot on the heater box to connect any ducting either.

If somebody has a 82 or newer rabbit without A/C, could you please take a picture of the heater box, heater controls and the air inlet for the heater under the hood? I'm curious of if I have the right heater. Thanks a lot.

burn_your_money · « **Reply #12 on:** January 21, 2008, 10:45:30 pm »

sethyboy85 is 100% for sure sounds like it's an issue inside the heater box. It isn't hard to remove the dash, shouldn't take more then 25 minutes. The 2 10 (or 13) mm bolts in the rain tray are the trickiest.