I have a 1998 Jeep Cherokee Grand Laredo that had approximately 185000 miles on it. I really love the car and would rather not have to replace it. I’ve had this problem with the car for about a year and a half. A couple of weeks ago I submitted a question because I was getting white steam/smoke coming out of my right front car vent. I’m grateful to everyone who responded. Many said that I needed to replace my heater coil. Well, my mechanic checked the car and said the heater coil is fine; he did some other stuff but I still have the problem. And now, on top of the white steam coming out of the right front vent, it starts coming out of the window defrost vent. It appears at random times, sometimes when I have the air on, at other times when the heat is on. And now, my windows are constantly fogged up. Every morning, I’m driving to work with fogged up windows. The only thing that seems to work is if I blast it with the air conditioner set really cold. But now that It’s getting cold outside, I don’t want to drive like that. Please help.
You have described the classic symptoms of a leaking heater core.
I suggest that you take the vehicle to a different mechanic for diagnosis and repair. If you continue to breathe the aerosolized coolant that is being spewed in the car’s interior, you will wind up with some really nasty respiratory problems, such as pneumonia.
Exactly right & a VERY simple test to prove the heater core is leaking is to simply bypass it.
I’ve had the heater core on my 87 Ranger bypassed for 2 years now. i’m in Socal so I dont really need the heater.
Have the mechanic remove the hoses from the heater core & connect them together with a 50 cent plastic connector.
Does the steam smell sweet? If so, you’re smelling the glycol antifreeze in the coolant and it is certain that the heater core is leaking.
Thank you to all who replied. I think I’ve finally convinced my husband it’s the heater core but he still wants our usual mechanic to do the work. Our usual mechanic gets very good reviews on this site but I think he doesn’t know how to diagnose problems.
To 87 Ranger: you solution seems easy but we’re in New England and it gets a little cold up here in the winter.
Perhaps the heater core is OK, but a hose or connection is leaking coolant into the airbox which gives the same result. Replacing a heater core isn’t hard, getting access to it is a bear. It involves taking apart most of the dashboard and many mechanics don’t care for the job. It is messey, you have to work in cramped areas and in odd positions, just not fun at all.
If the heater core is okay but a hose or connection is leaking coolant into the airbox is the process the same as for the heater core, eg, need to get in through the dash board?