[ridethelightning]

Hi All, I Have A '00 Eldo Esc With Aboiut 50k Miles. For The Past 5 K Miles Ive Heeard A Tapping Noise At Idle, Non Steady, And Worse When The Engine Is Hot. Sometimes When It Was Cold I Wouldnt Hear It. Now I Seem To Hear It All The Time Cold And Hot, And Still At Idle. I Work At Ford Motor Co. So I Took My Car In The Back, Had The Techs Licten To It With Thier Chassis Ears, And They Seem To Think The Noise Is Coming From The Timing Cover In Front, Or Possible The Serpintine Belt Tensioner Is A Little Loose, Or Even A Lifter Noise. I Seem To Hear The Noise From The Rear Bank, But They Seem To Think Its Coming From The Front Head. If Any One Has Had A Similar Problem Pleas Elet Me Know, Or If They Have Any Tips For Me. I Use 5w-30 Mobil One Full Syn. Always, With Ac/delco Filter. My Last Oil Change I Used 10w-40 To See If There Would Be Any Change In The Noise. The Noise Isnt Really That Loud. Im Not Sure What A Lifter Sounds Like If They Are Pumping Up. Thanks Guys!

 

[Submariner409]

Re: Tapping Noise, Lifter Or Timing Chain?

:stirpot: The first place to answer that question is in the archives or search function at the top of the page. Look for symptoms such as "carbon buildup", "carbon rap", "northstar carbon noise" , etc. Once you have an idea of one or more of the causes for "ticking" or "knocking" in a N*, try a couple of (engine warmed to highway cruise) good, hard WOT runs all the way through 1st and 2nd, let the engine unload, coast down to 20-25 mph, and do it again. (The crap that comes out of the exhaust the first time will scare you...) Look at your Manual and run the recommended oil for your engine. Witch hunts for the ultimate oil will cost you sleep and money. Mobil 1 or similar synthetic is fine. The N* is a highly tuned high RPM engine, and should be driven, carefully, as such (don't abuse it : run it.)(There are 3 single row roller chains in a N*. If you don't have plastic chips in your ((cut open and inspected)) oil filter, you're OK there...)

 

[Trashman]

Re: Tapping Noise, Lifter Or Timing Chain?

my 99 is making the same noise sometimes,
thanks for the info

 

[ridethelightning]

Re: Tapping Noise, Lifter Or Timing Chain?

Thanks for the replys guys. Unfortunately i have tried cleaning the engine out running it at WOT, a few times, with no luck. I just ran a little marvel mystery oil in there to see maybe if It is a lifter noise and it quiets down. I must say though based on my own personal experience, it sounds more like a spark plug wire arcing, but muuuuch louder. With the chassis ears on i can stil hear the noise coming from the left cylinder even when giving it some rpm's. Its hard to determine where exactly the noise is coming from though. when at idle its easiest to hear, and it still "off beat" not a steady tapping or rythmic. I have access to just about anything i need since i work at a dealership here, maybe i could decarbon the engine and see if that helps? I would just buy the cadillac extended warranty, but ive been quoted over $2000.00 for it haha. a little steep for me. any other thoughts would greatly be appreciated

 

[powertakeoff]

Re: Tapping Noise, Lifter Or Timing Chain?

Hi guys! I just bought a Cadillac Deville 2004 Northstar 4.6 with 90 mi on it.
The noise starts only when engine gets hot and never in cold condition. Cold engine sounds like brand new. I`am sorry for my broken english just came from Ukraine and still on learning process. I`am licensed heavy equipment tech with 20 years experience but never worked on small engine like that.
Please watch the video vith sound http://youtu.be/Yr8JOgFHEhg

Thank you guys for any help with that!

Alex

 

[Submariner409]

Re: Tapping Noise, Lifter Or Timing Chain?

The 3 timing chains have hydraulic (engine oil pressure) tensioners with nylon slipper faces - when they wear down there's a distinct whine - slapping is not usual.

The roller cam followers use static lash adjusters - the picture. One of those could be stuck - the noise sounds to be at 1/2 engine speed, so that points to valves - BUT the noise is louder at the oil pan than up top. Maybe listening under the removable top engine cover would help.

90,000 miles ?

For more Northstar parts pictures and diagrams, click my username and open the profile. Left column - 2 albums 6 pages of Northstar information.

Welcome Aboard and welcome to America !!! :highfive: (I do not envy your fellow countrymen)

 

[Ranger]

:welcome:

What weight oil are you using?

 

[powertakeoff]

Thank you guys :highfive:! Right, more sounds from oil pan. I tryed to listen this engine with stethoscope its realy hard to locate, it`s coming from deep inside.
I used 5-30 mineral oil, but switch it (for experiment) week ago with 15-40 so now it`s liiiitle bit quite. Sometimes this sound disapeared even when engine is hot, but most time it presented. Today I`ll try to listen it with more attension on top of the engine . Thanks gus again for your attension !

 

[Submariner409]

Regardless of the tapping noise, the bearing tolerances in the Northstar engine are NOT set for 15W-40 HD engine oils.

 

[Ranger]

Yeah, I'd stay with 10W30.

 

[powertakeoff]

Spent more that a hour trying to locate that noise with stethoscope - wierd. Noise coming from every where. Listening by ears it`s comming from oil pan but stethoscope shows everywhere.
please watch another video with sound http://youtu.be/YL_fJVz4-Sg

I think its intermittent clicking noise

Thank you guys in advance for your help

Alex

 

[rodnok01]

They can be hard to track down. Might want to remove serp belt and run for few even. Eliminate those moving parts at least and check the wp idler.

 

[Ranger]

:yeah: Good thought.

 

[basscatt]

They can be hard to track down. Might want to remove serp belt and run for few even. Eliminate those moving parts at least and check the wp idler.

----------------------
I was thinking the same thing -

 

[98eldo32v]

Tapping noise.......

Check rear vale cover closest to number one cylinder area.

Noise not noticeable when cold, when vehicle is warm still not noticeable EXCEPT after 5-10 idle time.

Noise disappears when idle speed/engine rpm is raised.......

My conclusion......oil pump not pumping sufficient pressure at lower rpm.

Oil pump swap........

 

[Submariner409]

His 2004 uses an entirely different valvetrain actuation system than yours, so the oil pump the oil pump thing is a stretch .................

Maybe one or two of the static hydraulic lash adjusters has a chip of dirt on the check valve - perhaps a can of engine cleaner snake oil is in order.

 

[98eldo32v]

My 00 deville should have the same valve train are close to it as an 04, Pre 00 had lifter buckets.

Yet, one thing the both generations had in common was the oil pump.

There was a thread a while back with a member with a similar issue and he swapped the pump and the noise was gone.

 

[98eldo32v]

http://www.cadillacforums.com/forums/cadillac-deville-1985-2005-including-1985/261887-2000-deville-oil-pressure-low-stop.html

 

[Submariner409]

Yes, but that had nothing to do with tapping at low speeds - that oil pump lost prime - after the front end of the car, up in the air on jackstands for a week - might have caused the oil pickup tube to drain back. A gerotor pump isn't efficient at pumping air, so maybe pressure was lost that way.

 

[98eldo32v]

Sub,

All I'm saying with those motors burning oil and running low, there maybe some wear induced over time on the gears causing a loss of pressure at idle. It won't take a lot of wear to drop a psi or two.