Recently, the heater in our '98 D (5.2 w/ AC) started blowing what appears to be steam (the wife calls it smoke)...it is odorless but really fogs up the car...after letting it run for a while with the fan on full speed, it appears to go away...any thoughts or suggestions?

 

I'm sure you have probaly fixed it by now, but just to post a follow up. We had the same thing, except that it only happened intermittently. The cooling system developed a pinhole leak in the heater core which only fogged the winshield when I floored it. It was never enough to leak out. Caused such a fine mist, it looked just like smoke. Winshield and other windows would fog up. When I wiped it, it looked a little dirty, so I thought it may have been transfluid leaking (just had an trans fluid exhange done).

End result, Paid $500 to have the heater core changed. Core was $25. Labor was $475. Dash has to be removed, A/C drained, disconnected. Entire A/C housing need to be removed. Pain, but now no problems!

 

thanks for the input Steve...I was dreading the heater core solution...the problem seems to have gone away but I might be in denial...not too happy about spending $500-700 labor for a $25 part...this problem coincided with the thermostat going bad...is it possible for this type of problem to occur as a result of overfilling the radiator and reservoir?...I changed the thermostat and may have filled the reservoir too much...after driving the car for a couple of days now (80 miles per day), there hasn't been any fog/steam...heater and defroster work fine...am I being over optimistic or do I see a new heater core in my future?

 

$25 dollar part? Don't like the price on that one! I paid $150 for my core and that was shopping around everywhere! $150 came from the dealership as they offered a 3 year warranty on the part and the aftermarkets were at $99 but offered either 90 day or 1 year warranty.

Also, when you go purchase the core yourself, MAKE SURE you inspect the core before you leave their premises. Sometimes you may get a core that is already bad or deteriorated!! Happened to me when I bought a core from the dealership. The first 2 cores he took off the shelf was either rusted heavily or seemed to have been used before. The 3rd and last core he took off the shelf was in brand new condition!! So I am confident my new core will last at least the full 3 year warranty! My personal mechanic installed the core for me for $400 labor cost which I felt it was cheap. You should see the amount of work it takes to replace the heater core! Steering column assemby needs to be removed, the entire dash assembly needs to be removed to reach the core. Wished Dodge made a back door in the engine firewall for easier access to the core.