Hi, I'm looking to buy a 1972 Volkswagen beetle and it has no heat on the inside even if it is running for a while. What could be the cause of this and is it a big problem? I'm not worried about being cold in the winter, I just want to know if it can be problematic with the engine somehow.
Go to where the running board meets the rear tire (in that area) Reach in that hole area and you should find a tan colored vinyl covered tube. there is one for each side of the car and it is the flexible connection to the heater boxes to the car. It is an easy fix. Maybe the tubes (which are about a foot long) are missing. It is something I would let the VW repair shops fix it...for you may need the parts or they are just not connected.If it was a water heated car, it would be like a hose or two were missing and the coolant was just spewing out onto the ground.
Air cooled VW heater systems work well if they have been properly maintained. Here is how they work; The engine cooling fan forces air through heat exchangers off of the rear exhaust ports. There are flapper valves that open to allow that flow to enter the cabin. The controls are on the tunnel, next to the brake handle. Bu sure the wires that operate the flaps are hooked up and move, be sure the exchanger flaps work in the diverter valve, and that the hoses that connect the exchangers to the body are there. Check also for rodent activity! Mice love to build nests inside all those ducts.
The heat exchanger are tubes around finned exhaust pipes, and they can get rust holes. But the main cause of no heat is simply the steel control wire breaks. It is inexpensive, and is easily run from the inside handle to the flap lever on the heat exchangers on the engine. But the tubes often get clogged with rust and dirt, so it is hard to get the cable through. You then have to take a long rod, widen the tip slightly by hitting it with a hammer, and then route out the tubes by putting the rod in an electric drill and pushing and pulling until they are clean. Then stuff them with grease as you insert the control wire. There is a simple 10 mm bolt clamp at the heat exchanger flap control lever. Have one person operate the inside lever, while someone underneath watches.
The parts to check are: (starting from the back) The hoses between the upright fan and the heat exchangers. (are they present, connected and intact?) The heat exchangers. (are they present, rusted out?) The heater flapper and cable. (are they present , connected and move freely when the levers are moved?) The metal heat tube that connects the heat exchangers with the front heater vents. (rusted or clogged) The heater distribution valve under the dash. (connected, rusted, clogged?) Air cooled VW's have never had very good heaters and it took only a minor leak or blockage anywhere in the system to make them inoperative. That is why there was an option for a gas heater on many models. It was rare to find one on a U.S. model, but very common in Europe. I owned VW buses while in college in the Boston, MA area. It gets COLD there in the winter and VW owners learned to dress warm.
