Just bought a 99 Deville - question about the oil
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Results 1 to 5 of 5
Northstar Engines and System Technical Discussion Discussion, Just bought a 99 Deville - question about the oil in Cadillac Engine Technical Discussion; I just picked up a 99 Deville with 55,000 miles. The car is super clean and looks to be in ...
  1. #1
    PRS2012 is offline Cadillac Owners Member
    Automobile(s): 1999 Deville
    Join Date
    Sep 2012
    Posts
    4

    Just bought a 99 Deville - question about the oil

    I just picked up a 99 Deville with 55,000 miles. The car is super clean and looks to be in mint condition. I purchased it from an elderly couple who kept in very good condition and have all service records stashed in the glovebox. They told me they purchased the car used from a dealer about 5 years ago with 35,000 miles.

    Since then, they have have been running synthetic oil in it. From what I understand, conventional oil is best for the Northstar.

    Would it be best to switch back to a conventional oil, or should I stick with the synthetic oil? Everything looks nice underneath with no oil leaks currently.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    Ranger's Avatar
    Ranger is online now Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,756

    Re: Just bought a 99 Deville - question about the oil



    Use whatever tickles your fancy. Either will serve you well. Just use 10W30, NOT 5W30.

    And change the coolant every 2 years.

  4. #3
    PRS2012 is offline Cadillac Owners Member
    Automobile(s): 1999 Deville
    Join Date
    Sep 2012
    Posts
    4

    Re: Just bought a 99 Deville - question about the oil

    Thanks for the welcome. Just from what I've read here in the short time I joined, Northstars have a tendency to leak and is more prone to leak with synthetic. I was thinking about maybe just running conventional Castrol GTX 10W30.

    Like I said, no leaks so far but if it could be avoided with conventional oil I'd be glad to switch.

  5. #4
    Ranger's Avatar
    Ranger is online now Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,756

    Re: Just bought a 99 Deville - question about the oil

    First of all, it will leak no mater what oil you use (if it is going to), and secondly, if it's gonna leak, it would have done so by now. Use whatever oil you like best.

  6. #5
    Submariner409's Avatar
    Submariner409 is offline If it won't run, chrome it
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    43,988

    Re: Just bought a 99 Deville - question about the oil

    Run whatever brand or type of 10W-30 oil that floats your boat. The engine could care less. 7.5 quarts exactly, keep the level at the middle of the hashmark, no higher.

    Apparently the previous owners ran "synthetic oil" for 20,000 or so miles - and you don't know what was run before that - so according to your hearsay, the engine should be happily leaking oil. Is it ? (My 2002 Northstar has run synthetic oil for over 60,000 miles, the outside of the engine is absolutely dry and it gets over 4,500 miles per quart.)

    FWIW, You are in a Forum for car repair and maintenance advice: people come here with little and BIG problems. NO ONE normally comes here to post "My engine has 125,000 miles on it, runs synthetic blend oil, Widget filters and Sparko plugs and gets 32 mpg in the city. I love the car. What can I do to make things break ?"....

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting