02 Deville plenum question
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 9 of 9
Northstar Engines and System Technical Discussion Discussion, 02 Deville plenum question in Cadillac Engine Technical Discussion; A little more help please. I have an 02 deville. Started this high idle thing about 2000 miles ago (but ...
  1. #1
    SCOTTCHAPIN is offline Cadillac Owners Member
    Automobile(s): 2002 Deville
    Join Date
    Mar 2009
    Posts
    2

    02 Deville plenum question

    A little more help please. I have an 02 deville. Started this high idle thing about 2000 miles ago (but started out only doing it sometimes). Then recently the Check Engine Soon light came on and stays on and it is doing the high idle thing almost all the time now (but not all the time). After reading the posts I first disconnected the battery to let the system reset. No change. Then I sprayed some brake cleaner around the plenum while it was running and it slowed the engine idle. So, it looks like I've got a leaky plenam. I can fix that, however, is there anyway to do it without taking off the manifold? I haven't read of anyone else having the high idle (1500) thing. Are the two symptoms unrelated? It runs smooth when driving. Thoughts? Thank you, Scott

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    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
    44,230

    Re: 02 Deville plenum question

    The job cannot be done without removing the fuel rail, injectors, harness, and intake manifold, as the plenum is the connector between the throttlebody and intake manifold and there is literally NO way to remove it otherwise.

    It's not a bad job......a set of fuel injector seal O-rings (aftermarket) and the plenum (dealer). The intake manifold gaskets are supposed to be reusable, but you might want to replace them, too.

    For the plenum try www.gmpartsdirect.com , www.gmotors.com. For the O-rings and gaskets try www.rockauto.com. If you want to get it all from one dealer, try Luke in parts at Lindsay Cadillac, over there -------->

  4. #3
    nesty2k5 is offline Cadillac Owners Member
    Automobile(s): 2004 Deville DTS/ Gunmetal
    Join Date
    Sep 2007
    Posts
    1

    Re: 02 Deville plenum question

    I would like to thank you submariner for the great information. I just recently replaced my plenum myself, flawless job ,not too bad just the fuel rails were a pain but other than that the car is running better than ever.Ty and everyone in the forum with the info as well.

  5. #4
    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
    44,230

    Re: 02 Deville plenum question

    Tks for the feedback - did you take any pics, or do you feel like posting a "How to" in your own experience??? This group of loonies thrives on fixes and experience, so anything you can contribute is worth its weight in gold.

  6. #5
    bigtone's Avatar
    bigtone is offline Cadillac Owners Fanatic
    Automobile(s): 2010 DTS, 2006 DTS, 2001 Deville,
    Join Date
    Jun 2003
    Posts
    366

    Re: 02 Deville plenum question

    I just did 2 plenum replacements, one for my wife's 2001 Deville and the other for my son's 2001 Deville. Not to disagree, but I did it without removing the fuel rails. There is room to move the rails around to get at the intake bolts. The one bolt below the regulator was the hardest, but doable. I think it took less than an hour to do the second plenum. The job was very straightforward. There is just enough room to tip the intake up on the front of the engine and slide it out, then I rested in on the power steering reservoir. Although I had new gaskets available, I used a mirror to inspect the old ones and ran my finger over them to make sure they stayed in place. Also, I had to loosen the water pump belt guard, and also the support hook that the fuel lines bolt to, and there was enough room to slide the lines over with the manifold. Both Devilles had the 171 and 174 code, but my wifes had a racing idle, and my son's had a slow rough idle. His had the bigger split. The IAC was bad in my wife's car also, that accounts for the fast idle.

  7. #6
    97EldoCoupe is offline U.S. Patent #8,740,532 - www.studkit.com
    Automobile(s): 97 ETC, 04 Bonneville GXP, 2010 Sierra SLT crew cab /4x4
    Join Date
    Mar 2007
    Location
    London, Ontario
    Age
    28
    Posts
    2,434

    Re: 02 Deville plenum question

    I've got a bunch of brand new GM factory intake manifolds with the seals/gaskets already installed. Let me know if anyone needs some. Not usually a reason to replace these, but just in case...

  8. #7
    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
    44,230

    Re: 02 Deville plenum question

    Jake - PM me. I want a spare 2002 Northstar VIN 9 intake for no good reason at all.............Jim

  9. #8
    97EldoCoupe is offline U.S. Patent #8,740,532 - www.studkit.com
    Automobile(s): 97 ETC, 04 Bonneville GXP, 2010 Sierra SLT crew cab /4x4
    Join Date
    Mar 2007
    Location
    London, Ontario
    Age
    28
    Posts
    2,434

    Re: 02 Deville plenum question

    Jim - if you can round up a carb gasket kit for a 76 Delta 88 / 455 we've got a trade on our hands....parts are getting scarce for these QJets....

  10. #9
    97EldoCoupe is offline U.S. Patent #8,740,532 - www.studkit.com
    Automobile(s): 97 ETC, 04 Bonneville GXP, 2010 Sierra SLT crew cab /4x4
    Join Date
    Mar 2007
    Location
    London, Ontario
    Age
    28
    Posts
    2,434

    Re: 02 Deville plenum question

    Sub - PM sent

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