Crikey, does anyone else own a 99 Dodge Ram? And is yours a piece of shit, too?
This week it’s the defroster. It blows (hee hee) and heat comes out…but all the windows fog up.
My mechanic took a half-assed look at it. He said that sometimes fluid leaks in the heater core (whatever that is) and that the fluid fumes or something causes the fog. I don’t know; I live in Oregon. I don’t even know how to pump gas.
I haven’t done too many tests, but it sort of seems to me that it’s worse when the defroster is full blast and on. The fog doesn’t go away if I switch the heat to the floor…this truck has always been touchy on the defrost issue. Unless there is air blowing on the windshield and out those little side vents that go to the side windows, and it’s the least bit chilly out, there’ll be condensation on the windows. But at least it would go away. Not any more.
It started off gradually. I noticed last week that the right passenger window kept fogging up. A few days later, it and the driver side window did, too. Yesterday…bam. ALL windows fog up now. It’s at the dangerous-to-drive point.
I don’t know what to do. The mechanic said he doesn’t want to tear the dash apart looking for a problem he doesn’t think exists. Taking it to the dealer? This post would have to go into the Pit in order for me to even consider that possibility.
I go with your mechanic. It sounds like a leak in the heater core with vaporized engine coolant being blown across the windows. Do you notice any sweet “oily” odor in the cab?
The heater core is the small chamber where the engine antifreeze/coolant is pumped after it comes out of the engine and before it goes back into the radiator to be cooled. When you run the heater or defroster, the air that needs to be warmed is blown across the heater (the core holds the fluid and is surrounded by vanes that warm the air as it passes over).
With a leak in the core, the hot engine antifreeze/coolant is vaporized as it goes past the leak and is sprayed into the cab. Since it has a chemical base, it will build up on the windows and eventually obscure them until it is washed off.
The other (less likely) possibility is that your air conditioner compressor has a problem. Most newer modls tie the a/c into the defroster because air that is too hot (and moist) defeats the intent of the defroster and the a/c dries the air while preventing it from getting excessively hot. I don’t know what your weather has been like, but if you are on the damp coast and the a/c is broken, you may be getting excessively warm, moist air defeating the defroster.
I would vote frst for the heater core (which is frequently found on the right side under the dashboard).
Yeah, you’re getting water into your heating systems ductwork. It’s pretty common, especially in older vehicles. A leak in the heater core is the most likely culprit, although there are other possiblities. Some heater cores are pretty easy to change out, others not so much. I have no idea what’s involved w/ yours, maybe one of our doper mechs. can help.
A friend of mine has been maintaining for over a month that he smells coolant when he rides with me. I don’t smell anything.
If this is happening, then wouldn’t my coolant level drop? And isn’t that bad?
Tomorrow I’ll try driving w/o the heater on…then I’ll turn it on. (As I said before, I swear it’s worse when it’s running and blasting on the windshield.)
Your coolant level will drop, but remember that the leak may only be the size of a tiny pin hole. If you are not driving for hours at a time, it will not have time to expel a great volume of coolant. (Nor does it need to in order to mess up your windows. You’re only getting a fine mist, not a torrent of fluid on the window.)
I can smell an antifreeze leak in a heater core when I ride in a vehicle and I tell the person to get it fixed. Nothing else has the coying sweet smell of antifreeze. I had the heater core fail in a spectacular way. The truck cab was full of a fog withing one or two seconds, and I had to pull over by feel. I had been going down the interstate at 65 mph. I couldn’t see my hands on the steering wheel. Buy a new heater core and not a rebuilt. Many times a small leak can take a couple weeks to show a drop in the radiator level. The heater core is the highest point in the system, so that’s where the air collects first when the vehicle cools down. The cooling sytem radiator can be full of air in the heater core and feed hoses.
You have described the textbook symptoms of a leaking heater core. The description alone makes it a virtual certainty. Comfirmation can be had by the very simple act of running a finger on the inside of the windshield, which is almost sure to have a thin film of antifreeze on it, with its characteristic oily feel. Alternatively, a standard cooling system pressure test can be done, watching for coolant to start coming out of the heater ducts. But really, there’s nothing else that could explain the symptoms described. I find it puzzling that he doesn’t think the problem exists - there’s no question that there is a problem, and there’s really no doubt that the heater core is at the root of it. If he thinks dash removal is necessary to verify that, he’s got a lot to learn.
Unfortunately for you, dash removal is necessary to fix the problem. A typical price might be in the 500-700 range. Ouch!
And yes, the engine coolant level is going down. When it reaches a critical point, engine overheating will occur, possibly causing further expensive damage. Until it’s fixed, check and top up the engine coolant by removing the radiator cap (COLD ENGINE ONLY) and making sure the fluid level is up to the top of the radiator.
If money’s tight right now, it’s usually possible to bypass the heater core by rerouting hoses in the engine compartment. This would isolate the leak from the system, but totally disable any heating function, so it’s only a temporary stopgap.
I was going to suggest trying to run the defroster with the temp setting all the way to “cold.” Won’t that bypass the heater core and thus aid in diagnosing the problem?
A 99 ram doesn’t use a heater control valve , instead it uses a door in the ac/heater case (blend door) which controls hot and cold air. Water flows through the core at all times.From the info provided it sounds like heater core seepage to me although a system pressure test would confirm or disprove this.