Developed an engine whine... what is it?
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
Page 1 of 3 1 2 3 LastLast
Results 1 to 15 of 43
Northstar Engines and System Technical Discussion Discussion, Developed an engine whine... what is it? in Cadillac Engine Technical Discussion; My car (98 Deville base) started making a strange whine from under the hood in the past 2000 miles or ...
  1. #1
    wingman0121 is offline Cadillac Owners Member
    Automobile(s): 1998 Cadillac Deville
    Join Date
    Apr 2014
    Posts
    44

    Developed an engine whine... what is it?

    My car (98 Deville base) started making a strange whine from under the hood in the past 2000 miles or less, it is present when the engine starts and the pitch of the whine changes with the engine RPM, sort of sounds like people who installed gear drive on a small block to drive their camshafts but not nearly as loud. The car has 218k miles. I took it to a car shop and the guy listened it with a stethoscope and he said the noise is coming from inside the engine. The car runs fine and it didn't change any driving characteristics this whole time, the oil is clean and I don't see any silver particles. Another shop said my power steering pump is going bad but I don't hear any weird noise or have problem turning the wheel while parked. I read about checking the pulleys by taking off the belt but my 1/2" ratchet is too short and there aren't enough room for my hands to move it.

    In the past 1000 miles or so I noticed a clacking noise from under the hood when I first start in the morning, it sounds a lot like the engine is knocking but goes away as soon as I drive off. It doesn't do it every time but I've never heard that sound before in the past 8 years, again the engine didn't lose power or anything abnormal when it does make that sound. I read about carbon buildup and I do give it the foot at least once every few days so it shouldn't be carbon.

    In any case I'm a little worried since I'm about to go on a 2000-mile round trip to visit my grandmother.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    rodnok01's Avatar
    rodnok01 is online now Cadillac Owners Connoisseur
    Automobile(s): 98 DeVille, 97 DeVille d'Elegance
    Join Date
    Feb 2012
    Location
    NC
    Posts
    4,226

    Re: Developed an engine whine... what is it?

    Could be a idler/tensioner pulley or alt or related, could be WP tensioner pulley. Take stethoscope and listen to each pulley and item. You can get cheap serp belt tool at Harbor Freight.

  4. #3
    wingman0121 is offline Cadillac Owners Member
    Automobile(s): 1998 Cadillac Deville
    Join Date
    Apr 2014
    Posts
    44
    Thread Starter

    Re: Developed an engine whine... what is it?

    I went to the shop and had them take the belt off and the engine still makes that noise while running, the whine sounds like it is coming from under the intake manifold.

  5. #4
    Submariner409's Avatar
    Submariner409 is offline If it won't run, stick on fender vents
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    75
    Posts
    45,953

    Re: Developed an engine whine... what is it?

    WHICH belt ?? There are two - the main accessory drive serpentine belt and the water pump drive belt at the rear (driver's) end of the engine.

    Under the intake manifold is either a vacuum leak or a broken/faulty Bendix drive on the starter pinion gear.

    In the front (passenger) end it (discounting the p/s pump) would be one of 3 timing chains, 4 cam sprockets, chain tensioners/guides/slippers.

  6. #5
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    74,779

    Re: Developed an engine whine... what is it?

    Quote Originally Posted by wingman0121 View Post
    Another shop said my power steering pump is going bad
    Quote Originally Posted by wingman0121 View Post
    I went to the shop and had them take the belt off and the engine still makes that noise while running, the whine sounds like it is coming from under the intake manifold.
    Could it be a vacuum leak from the manifold over pressurization relief valve seal behind the P/S pump?





    The other possibility (if the noise is from the other end) is the starter not disengaging from the flywheel.

  7. #6
    wingman0121 is offline Cadillac Owners Member
    Automobile(s): 1998 Cadillac Deville
    Join Date
    Apr 2014
    Posts
    44
    Thread Starter

    Re: Developed an engine whine... what is it?

    Quote Originally Posted by Submariner409 View Post
    WHICH belt ?? There are two - the main accessory drive serpentine belt and the water pump drive belt at the rear (driver's) end of the engine.

    Under the intake manifold is either a vacuum leak or a broken/faulty Bendix drive on the starter pinion gear.

    In the front (passenger) end it (discounting the p/s pump) would be one of 3 timing chains, 4 cam sprockets, chain tensioners/guides/slippers.

    The accessory belt. I hope it isn't anything inside the engine because most car shops in my area HATES working on Northstar engines and opening one means they'll want to charge a bunch of money.


    Quote Originally Posted by Ranger View Post
    Could it be a vacuum leak from the manifold over pressurization relief valve seal behind the P/S pump?

    The other possibility (if the noise is from the other end) is the starter not disengaging from the flywheel.


    How do I go about checking the vacuum leak? As far as the starter not disengaging from the flywheel, does that mean the starter motor is being driven by the engine while the car's running?

  8. #7
    rodnok01's Avatar
    rodnok01 is online now Cadillac Owners Connoisseur
    Automobile(s): 98 DeVille, 97 DeVille d'Elegance
    Join Date
    Feb 2012
    Location
    NC
    Posts
    4,226

    Re: Developed an engine whine... what is it?

    I would take the WP belt off and check again. that little pulley makes a racket when wearing out(seizing more like it) and is very easy to remove using 1/4 inch rachet.

  9. #8
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    74,779

    Re: Developed an engine whine... what is it?

    Quote Originally Posted by wingman0121 View Post

    How do I go about checking the vacuum leak?
    Spray some Brakleen or TB cleaner into the tunnel behind the P/S pump. If you have a vacuum leak the RPM will increase.

    As far as the starter not disengaging from the flywheel, does that mean the starter motor is being driven by the engine while the car's running?
    Yes

  10. #9
    wingman0121 is offline Cadillac Owners Member
    Automobile(s): 1998 Cadillac Deville
    Join Date
    Apr 2014
    Posts
    44
    Thread Starter

    Re: Developed an engine whine... what is it?

    Quote Originally Posted by rodnok01 View Post
    I would take the WP belt off and check again. that little pulley makes a racket when wearing out(seizing more like it) and is very easy to remove using 1/4 inch rachet.
    I'm pretty sure it isn't the water pump since the noise isn't coming from that area, but since the car had its water pump replaced almost 100,000 miles ago (AC Delco part) I will check it tomorrow.


    Quote Originally Posted by Ranger View Post
    Spray some Brakleen or TB cleaner into the tunnel behind the P/S pump. If you have a vacuum leak the RPM will increase.


    Yes

    I sprayed some carb cleaner at the relief valve and the engine rpm didn't change. As far as checking the starter, since electric motors produce electricity while being turned by an external source is there a place in the fusebox or wiring harness where I can hook up a multimeter and see if the starter is producing power?

  11. #10
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    74,779

    Re: Developed an engine whine... what is it?

    I don't know about that. I'd just listen in the starter vicinity with a stethoscope. That should pretty much pin point the starter if that's the cause.

  12. #11
    wingman0121 is offline Cadillac Owners Member
    Automobile(s): 1998 Cadillac Deville
    Join Date
    Apr 2014
    Posts
    44
    Thread Starter

    Re: Developed an engine whine... what is it?

    Quote Originally Posted by Ranger View Post
    I don't know about that. I'd just listen in the starter vicinity with a stethoscope. That should pretty much pin point the starter if that's the cause.

    I'll get a set of stethoscope tomorrow, I assume ones for medical purposes works just fine? If the starter is really not disengaging at all then wouldn't it be broken after the many WOTs I did in the past 1000 miles? The car still starts just fine and its startup behavior is the same like before. I felt the clacking noise in the gas pedal last night while accelerating, again the car didn't act any different and the noise went away after a few seconds.

  13. #12
    rodnok01's Avatar
    rodnok01 is online now Cadillac Owners Connoisseur
    Automobile(s): 98 DeVille, 97 DeVille d'Elegance
    Join Date
    Feb 2012
    Location
    NC
    Posts
    4,226

    Re: Developed an engine whine... what is it?

    They sell a cheapo mechanics stethoscope with a metal rod on the end so you can pinpoint it on a bearing or area.

  14. #13
    wingman0121 is offline Cadillac Owners Member
    Automobile(s): 1998 Cadillac Deville
    Join Date
    Apr 2014
    Posts
    44
    Thread Starter

    Re: Developed an engine whine... what is it?

    Quote Originally Posted by rodnok01 View Post
    They sell a cheapo mechanics stethoscope with a metal rod on the end so you can pinpoint it on a bearing or area.

    Oh I didn't realize that it's a bit different after looking at harbor freight, I will visit auto parts store tomorrow and see.

  15. #14
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    74,779

    Re: Developed an engine whine... what is it?

    Either buy a mechanics stethoscope or convert a medical one like I did by removing the chest pad and replacing it with a copper tube.

    ----------

    Quote Originally Posted by wingman0121 View Post
    If the starter is really not disengaging at all then wouldn't it be broken after the many WOTs I did in the past 1000 miles?
    I'm not sure how long a starter motor can survive like that.

  16. #15
    wingman0121 is offline Cadillac Owners Member
    Automobile(s): 1998 Cadillac Deville
    Join Date
    Apr 2014
    Posts
    44
    Thread Starter

    Re: Developed an engine whine... what is it?

    Okay will do. I suppose a last ditch effort to see if the starter is not disengaging without taking off the intake manifold is by turning the key to start when the engine's already running? If it makes that awful noise then that should mean it's disengaging correctly.

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