Hey guys,

How do you go about taking off/out the flap that regulates the fresh air / hot air that comes into the airbox. Mine is broken and always lets in the heated air. I've tried taking off that whole section of piping that contains the flap, but I can't figure out how to get it off. I'm going to seal off the heat intake with a cap and just let fresh air come through from the front. I'm also going to turn the fresh air intake around so it faces out instead of at the radiator so air is forced into the airbox at speed and put mesh on it so rocks and other debris does not enter.

Thanks - Mike

Fairly simple procedure. Remove air filter like you were just going to change it, pull both sections of air box from car, thermostat is located on front section. Just snaps onto box with detents on three legs, pry off. Plug intake air hole and leave thermostat out completely, including mounting legs. I plugged air intake with half a plastic pill bottle and some tape, and has run great ever since. More power and better gas mileage.

Tom Higgins

On my 1989 744gl (b230f, lh-jetronic 2.4) there isn't a thermostat is this right? Just wondering how this flap works on mine.

I think they only had the pre-heat setup on 1990+ Volvos. If you have it for some reason, you would have a second hose coming into your airbox made of flexible metal that runs underneith the fan and attaches around the exhaust manifold.

Yes, this flexible metal hose is there, also this flap, but no thermostat. Removed the air box and saw an hole with such an break-out-plastic-piece in it (diameter about 1/3") seems to be the place where thermostat belongs. There are also some unused connectors there (beside those for removed headlight-wipers) but don't remember the shape. Is it possible to fit the thermostat an if yes what does it do?

I don't know how to get the thermostat in there, but I think it controls the flap that regulates the flow of incoming hot air or cold air. Cold air comes from the short hard plastic hose that goes around in front of the radiator to collect fresh air. The heated air comes from the metal flex hose. I'm in the process of removing the flap entirely and capping off the heated air for better performance.

-Mike