My 1998 Cadillac keeps overheating and we cant figure out why

20

Asked by cdb520 May 04, 2015 at 01:07 PM about the 1998 Cadillac DeVille d'Elegance Sedan FWD

Question type: Maintenance & Repair

I have a 1998 Cadillac Sedan DeVille. It started over heating recently and we had a leak
in the radiator so we had a new one put in. That was in January. The car ran fine until a
couple weeks ago and it started overheating again. It loses the water or antifreeze
because it boils out from under the cap when it gets hot. We put in a new water pump
and a new thermostat and that didnt help. We took the themostat out and that didnt
help. Se we bypassed the heater core thinking that could be the problem but it wasnt.
All of the belts are on and working as well as the fans. We rented the equipment and
checked to see if it was the head gasket and it wasn't. The car puts out no smoke and
there in no coolant in the oil. There is no oil in the coolant either. The car runs great  
except it quickly overheats. We are going to flush the system even though it was done
in January. We are running out of things to check. I hope someone can help me please.

9 Answers

144,885

I know you just put a new water pump on,but i think this may the issue,some replacement pumps are bad,and from what you have done so far,crank car with cap off, have radiator full of fluid,and let it heat up,you should see the water circulate,if not it will be the new pump,if you do see it moving then replace the radiator cap,it is not sealing.

9 people found this helpful.
100

I have a 95 deville and am having the same exact issues ..sometimes it over heats sometimes it won't ?I have no clue what is wrong

3 people found this helpful.
30

@sts... SAME THING! I have a 98 dfeville... replaced everything you did! still over heats! it just started one day out of nohere! put bars leak too! still overheating! so... my battery dies 3 days ago... I get a jump. now battery system light says not charging! car wont start unless it has a jump! and dies out sometimes when it wants! I was told that the WHOLE computer system has to be reset from dealership. overheating issues might have been cuased ecause my EGR vavle needed to be replaced about 3 months ago... and I didn't replace it... and since caddys are tempermental... it threw off sensors EVERYWHERE like to the cooling system... and with my battery going dead it triggered something else to go off!!!!! I just sold it today! don't want to spend or deal with it to find out what next!!!! good luck!

3 people found this helpful.
180

So on some forums I've noticed that the reservoir tank cap may be a 16 psi when OEM is 18psi. My 02 Deville DTS is doing the same thing I'm starting with a $5 cap from autozone. Because I have a new water pump, belt, thermostat. Only things not changed are radiator and pressure cap.

2 people found this helpful.
40

I have a 1998 caddy deville that ran hot. I cleared the recovery hose that feed the water pump that took care of it . the original pipe is to small and clog very easy.

4 people found this helpful.
30

Its the head gasket. After the car cools off, smell inside the radiator reservoir and see if it smells like gas. If it does then the gas and antifreeze is mixing. Also the antifeeze is being burnt away with the gas, meaning disapearing antifreeze. Beautiful car, but will need new engine. Old engine is not worth taking the risk to fix cause of how complicated its built.

3 people found this helpful.

Your Answer:

DeVille

Looking for a Used DeVille in your area?

CarGurus has 7 nationwide DeVille listings and the tools to find you a great deal.

Postal Code:

CarGurus Experts

  • #1
    James Sparrow
    Reputation
    4,090
  • #2
    tuff4x4
    Reputation
    3,110
  • #3
    Cynthiasmith
    Reputation
    2,840
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Cadillac Escalade
15 Great Deals out of 427 listings starting at $9,995
Used Chevrolet Corvette
22 Great Deals out of 1,084 listings starting at $15,000
Used Lincoln Continental
8 listings starting at $17,900
Used GMC Sierra 1500
132 Great Deals out of 6,515 listings starting at $3,975

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.