Getting a little nippy outside the last couple days, finally had to break down and do something about the lackluster heating in my truck. It wasn’t anything to write home about last winter, but I didn’t freeze, so I put up with it. This winter, however, it was noticeably worse, so it had to be dealt with.
For those who are less than mechanically inclined, there are many simple things that can go wrong with a car or truck that you can fix yourself, if you take your time and don’t get intimidated. Even if you don’t actually do the repairs yourself, you should at least understand and be conversant on the subject in general to keep from getting screwed by the repair shop.
Take this heater issue. Perfect example. I’d say 95% of the time I’ve dealt with low heat in a vehicle, it’s been the same thing – plugged heater core. The heater core is basically a little mini-radiator that sits inside your dash. The engine circulates hot coolant through it and the fan inside the dash blows air through it, generating nice hot air.
Heater cores are little things. They have lots of small passages. There isn’t a lot of direct pressure to force the coolant through the heater core. Eventually, dirt, corrosion and deteriorating antifreeze contribute to a plugged core.
To diagnose, run the engine with the heater turned on until it warms up nicely. Pop the hood, and you’ll see 2 hoses about 1 inch diameter each going into the firewall (engine side of the dash). Feel the hoses. If one is hot and the other is lukewarm or cold, your heater core is plugged. If you’re the handy sort, you should be able to round up a garden hose and rig up a connection to the cold hose, unhook the hot, and force clean water backwards through the core. I did mine in about 5 minutes. Run it until it’s clean and flowing nicely, hook it back up, and test again.
If you don’t like getting dirty or you don’t have time to fix it yourself, at least you’ll know enough to make the mechanic nervous. As sad as it may be, if you talk to a mechanic and tell them you have no idea what can be wrong, you’re very likely to end up with a higher repair bill than if you tell them you’d like a radiator and heater core flush.