1999 Ford Expedition Heater core going

Tiny
BTAKASPER
  • MEMBER
  • 1999 FORD EXPEDITION
  • V8
  • 2WD
  • AUTOMATIC
  • 180,000 MILES
I have a 99 expedition and with the a/c going the car gives off a horrible odor. I checked with a shop and he knew right away the heater core was bad and that's why it had a burning cat pee smell to it. Which outside the car smelled like burning coolant. I haven't got it fixed yet but its been about a week and a half. I had to replace the alternator yesterday cause while driving to work the battery gauge was dropping fast. Now today, the car ran fine but service engine soon light came on and the new alternator makes a whistling sound and there's also a hissing sound coming from it. Could the bad heater core be the culprit for a service engine soon light? I plan on getting it checked tomorrow for the light to find out exactly what the code is. I also have someone this weekend fixing the heater core this weekend. Is it bad to drive with a bad heater core if its not leaking inside the car, there's no big puddles underneath the car when its idling either.
Tuesday, October 20th, 2009 AT 3:50 PM

3 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
AS far as the heater core, just make sure the coolant doesn't get low. Also, I can't imagine the smell is good for you. Make sure you have a good mechanic replacing it because it is a major job to do the work. The entire dash needs to be removed and you don't want someone doing it that you can't trust.

As far as the alt, it shouldn't be making that noise. Is it a new alt or rebuilt?

Finally, when you have the computer scanned for the code, let me know the code before purchasing any parts. I doubt the alt has anything to do with it as well as the heater core. Most parts stores will scan it for free.

Let me know.

Joe
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Saturday, October 24th, 2009 AT 7:18 PM
Tiny
BTAKASPER
  • MEMBER
  • 4 POSTS
Well I got the heater core replaced. A Lady I work with, her husband is a mechanic for the city and works on all the police cars. So I trust him cause a few other guys at work recommended him for the job. He wanted 200 to do it, the shops around here all wanted anywhere from 600 to 750 to do it.

The alt was a rebuilt one from O'Reilly's.

I found out what was causing the service engine light, a vacuum hose had cracked. I noticed inside the car it wouldnt let me change from defrost setting on the vent settings. But when I looked under the hood I seen that, replaced the hose and now it works again. Do some vacuum hoses allow the changing from defrost to vent, or vice versa?
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Sunday, October 25th, 2009 AT 7:50 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
I'm glad you got it fixed. As far as the vacuum leak, the vents are actuated by vacuum, so yes the air will only blow out of the floor or defroster.
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Sunday, October 25th, 2009 AT 2:22 PM

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