Cooling Systemin 1999 Caddy DeVille.

Asked by Aug 05, 2014 at 01:06 PM about the 1999 Cadillac DeVille Concours Sedan FWD

Question type: Maintenance & Repair

My check coolant level warning is coming on.  I am not overheating but I need to add a gallon of coolant every 50 miles.  Had a pressure test done and all was O.K.  Radiator cap seal was bad so he replaced with a Motorad 16 radiator cap.  I'm still getting the warning every 50 miles and the last time I had to add 3 qts. of coolant.  Could the new radiator cap be the wrong one?

2 Answers

485

The most common cause is a bad thermostat. You can purchase a thermostat, gasket, and some blue rtv and do the job your self. After the car has cooled, locate the thermostat housing, remove the bolts and remove the housing. Remove the thermostat, and the old gasket. Be sure to clean the surface thoroughly. If the surface of the housing has corroded then that will need to be replaced as well. Assemble the termostat, gasket, and housing using the blue rtv. Allow it to cure for an hour at least. Add coolant and crank. Drive 30 miles, leave the car running, check all hoses, hose ends, around the thermostat housing and the water pump for signs of leaks. If you smell a sick sweet smell then antifreeze is leaking out and burning. If the tailpipe has that sickly sweet smell then you may have a warped head or blown head gasket.

1 people found this helpful.

Thank you, I will tell my mechanic what you said.

Your Answer:

Cadillac DeVille Experts

  • #1
    kikero
    Reputation
    2,310
  • #2
    Js08016
    Reputation
    2,060
  • #3
    Cynthiasmith
    Reputation
    1,840
View All

Related Models For Sale

Used Cadillac Eldorado
299 listings starting at $2,995
Used Cadillac Seville
3 Great Deals out of 257 listings starting at $1,495
Used Chevrolet Impala
369 Great Deals out of 25,580 listings starting at $950
Used Lincoln Town Car
29 Great Deals out of 1,455 listings starting at $1,900
Used Cadillac Escalade
215 Great Deals out of 11,991 listings starting at $2,990
Used Ford Mustang
273 Great Deals out of 37,435 listings starting at $1,350
Used Chevrolet Camaro
233 Great Deals out of 27,298 listings starting at $2,077
Used Chevrolet Corvette
91 Great Deals out of 15,032 listings starting at $3,620

Used Cars For Sale

2003 Cadillac DeVille For Sale
149 listings starting at $2,300

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.