Hello!

I've got a 1990 240, with about 170K miles on it. I do most of the work on it myself, and am very diligent about keeping it in fighting shape.

So, I live in Michigan, and it's starting to get colder and colder outside. I've never had any problems with the heater (I've owned the car for about 8 years), but the heat isn't that hot. The fan seems to be blowing as it always has, but the hot air isn't that hot. It's not like it's super cold in the car, but I'm nervous about when we get more snow, and the car might have issues defrosting the windshield.

I have been doing extensive engine work in the past month (cam, crank seals, timing belt, etc), and maybe I bumped a hose or something? The A/C compressor seized at the end of the summer, not sure if that is relevant.

Any help would be greatly appreciated. Thank you!

 

on a 240, the heater valve is near the gas pedal under the center console, remove the driver side kick panel and the left side panel of the console to find it. the control cable may have gotten unhooked

my daughter's 87 had the older style, which has a copper thermo sensor tube... it failed so the heater was either ON or OFF, no medium. I used this part to repair it, Volvo 240 heater valve kit replaces 1348252 9131998 $59! Volvo 240 heater valve kit replaces 1348252 9131998 $59 [] - $59.00 : EuroPartsHouse Bargain Parts
(see the link to the instructions for what the old style and new style look like, I think your 90 is 'new style').

the AC compressor would have zero impact on this. if your engines thermostat is stuck wide open, maybe the engine is never warming up enough but I kind of doubt that. if you'd knocked a tube loose, you'd have coolant spilling everywhere.

 

Is your engine temp gauge getting to the 9 oclock position or does it hover around 7 oclock? I live in the Chicago area and had a thermostat fail in the open position and it took a while to get warm air out of the heat when it was cold out. The temp gauge needle would not get past the 7 oclock position. Once I replaced the thermostat, the heat blew nice and hot.

 

Pierce, just took a look at the valve, and it's still hooked on. You said your daughter's failed so that the heat was either on or off, mine can still be adjusted, it's just that the hottest it is going is not very hot. Could that still be a heater valve?

Act1292, yeah! My engine temp gauge never goes beyond seven o'clock. I figured something was wrong with the cluster, because the mechanical clock doesn't work accurately. Are there any other issues or side-effects I would be experiencing as the result of a failed thermostat?