Why does my heat work only when I get to a certain speed? Coolant levels are where they should be. I've had the radiator flushed, replaced the thermometer, radiator cap, and heater control valve.

Asked by ggarci21 Feb 03, 2015 at 11:53 PM about the 1988 Cadillac DeVille Sedan FWD

Question type: Maintenance & Repair

I have a heater issue. My heat only works when I hit about 30 mph. It stays hot only if I
maintain or increase that speed. I have replaced the thermostat, flushed the radiator, and
replaced the heater control valve. My vehicle is a 1988 Cadillac DeVille. It has
approximately 90,000 miles and seems to be in good condition otherwise. The ac service
light comes on and throws the system into ECON mode instead of AUTO.

2 Answers

100

i have a similer problem with my 93 i'm going to replace my heater core it may be clogged from age. when i flushed the system the coolant was really rusty looking and its never been done.

Your Answer:

DeVille

Looking for a Used DeVille in your area?

CarGurus has 278 nationwide DeVille listings starting at $3,250.

ZIP:

Own this car?

Share your experience with others.

1988 Cadillac DeVille

Review another car

CarGurus Experts

  • #1
    james sparrow
    Reputation
    4,050
  • #2
    tuff4x4
    Reputation
    3,070
  • #3
    Cynthiasmith
    Reputation
    2,840
View All

Know more, shop wisely

Search

Related Models For Sale

Used Cadillac Eldorado
165 listings starting at $2,950
Used Lincoln Town Car
15 Great Deals out of 396 listings starting at $1,000
Used Cadillac Seville
47 listings
Used Ford F-150
5,876 Great Deals out of 119,747 listings starting at $1,995
Used Lincoln Continental
29 Great Deals out of 607 listings starting at $9,660

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.