Ok, here's the situation. I have a 93 4.0 aero, and it has front and rear heat and air. For the last week or so, when I use the heater I occasionaly smell coolant. I've looked and I haven't seen any evidence of coolant leaking from any of the hoses or anywhere else. But if I look in the radiator, it is a bit low. Not much, probably less than a cup of coolant. And the smell is intermittent. Sometimes I smell it going up or down a hill, sometimes on a sharp turn. Not so much when its a straight road. At first it wasn't very often, but it seems to be more frequent lately.

I've read the various posts about replacing the heater core and I'm not to worried about it, but I would like to make sure thats it before I do it. Thanks.

 

if your van is steaming up inside alot,that is a for sure sign the heater core is leaking.
you could be smelling antifreeze leak other than the heater core. good luck

 

I Would check your heater hoses and connections (especially rear heater core,) I would also check the condition of your main radiator hoses to the block. You might be leaking under the hood and the fresh air intake is sometimes drawing it in.

 

Could be the start of the heater core leaking. The classic symptom is the smell and foggy windows, especially on the passenger side. You need to check the freezeout plugs. The 2 plugs in particular are located on the rear of the heads, just inside the interior rear engine access cover.

 

A foggy windshield is a sign of heater core leakage the reason being is the coils and fins become saturated with coolant and it acts and a humidifier.

 

Just this evening the passenger side of the windsheild started fogging up directly above the defrost vent. As far as the other suggestions, I've checked both of the hoses to and from the radiator, as well as the rest of the heater hoses under the hood. Unless its a pinhole leak in the back of one of the ones behind the alternator, I think that they're all fine. But in my experience, once a hose starts leaking, it blows really quick, so I think I can rule that out.
As far as the drainplugs, I'll double check them, but I just replaced the head gasket about 8 or 9 months ago, and I checked them all then, and they were fine. So I guess that its either the rear core or the front one. Is there any way to tell which one it is? Seems to me that since its fogging up the front windshield it would be the front, but given my luck its both or something. Thanks for the help.

 

On a friend's '90 Aerostar with a 3.0 V6, he was starting to notice the symptoms you described. You can flush directly the heater core, and the best way is to replace your heater hoses at the same time. This way, you can use the old hoses during the flushing process then discard. First, splice in a flushing "T" (like the common ones you see from Prestone, it will be a 3/4" T.) Do a regular radiator flush with the chemicals, drain and repeat the process. Always run the heater, with fan speed at MAX, especially too, on Aerostars with rear heat. Then, spice in a T about a foot (12") from the heater core inlet, near the Aerostar's firewall. The space is tight, but that's how the Ford engineers made it! Direct the flow or water, directly into the T at the heater core inlet. Cut the outlet hose, so you can see what is coming out. Important: if you have access to some hot water, this really helps out, because the hot water does a much better flushing job, than cold tap water. Start out slow, and when you see the water coming out of the heater core outlet hose, gradually increase pressure. Here's the kicker: When you see your radiator run clear during a normal flushing, you think the cooling system is clean, right? I did. But when you flush out the heater core, you will be amazed at the rust, scale, muck, and deposits that come out of the negelected core! I was very surprised. Flush the core for about 15 minutes, and then it too, will run clear. Stop/ this is when you can change the old heater hoses, with new ones. Go through the Ford parts dept. It'll cost about 35.00 more than aftermarket, but you get the correct length and quality. Refill system, first with water only. This way, any leaks, you can correct and not lose any coolant. Even with straight water, I took my friend's Aerostar for a ride, and both front and rear heat was toasty HOT and normal. A 40% coolant, 60% water mix and the heater worked liked new again. Nice , warm heat! What happens to, heater cores over time can get partially plugged, resulting in a coolant flow decline. That eventually causes scale and rust deposits resulting in leaks, which you'll notice with a coolant smell and misting on the windshield, especially during the "heat soak" period after a freeway run. Flush the cooling system once a year, every year! Even though the extended coolants say 5 years 100,000 miles etc. forget it. I'd say during a new car or pick-ups first five years, one flush is fine. When a car is 6-7 years old, start flushing the cooling system once a year. That alone will eliminate a lot of heater core problems later, I assure you.

 

I must be one very lucky guy. Both my Aerostars are over 10 years old and I haven't had any heater core problems, YET. I'm sure I'm overdue for it and it might happen anytime now . Maybe it's because I flush the cooling system every 2 years. Actually I timed it by the Congressional Election every 2 years. When the TV is full of political non-sense, I know it's time to flush