View Full Version : Loud Engine Whine

02-01-08, 01:14 PM
I have a terrible dilema. I bought a 2000 DTS with 114k miles on it. When I bought it everything sounded fine. It now has about 160k miles on it. For the last 5k miles or so the engine has developed a whine sound. Since it started, it's gotten louder and louder. The noise does increase directly with RPM and is very noticeable even at idle. I tried to determine the exact location of the sound. I first assumed it was the power steering pump as I've had a minor leak there before, but with closer inspection, it's not the PS pump. I wish I had a good stethescope so I could focus my listening, but don't. It seems like the sound is coming from the general area of the PS pump on the front passenger side of the engine, but more like it's somewhere under the head. Is this cam related? I've seen some articles about harmonic balancer noise in newer N* engines, but not mine specifically. I worry that this is something major mechanically and of course can't afford to pay $100+/hr to have a dealership tinker with it to figure out the problem. Anyone have insight?????


02-01-08, 02:30 PM
A stethoscope is not expensive and would be a great help. In liew of a stethoscope you could use a length of hose.

Try using a 1/2" breaker bar and put the drive lug in the square hole in the belt tensioner. Release the belt tension just enough to let the belt slip. If the noise goes away, it is one of the accessory bearings. Shut down and remove the belt. Spin each accessory and pulley by hand to feel for bearing roughness.

02-01-08, 03:52 PM
Wow, that's an excellent idea! I'll try that tomorrow. Sadly enough, on my way home from work I'm stopping by to test drive a Hyundai XG350 L. The fuel economy isn't much better, but Hyundai has an excellent name for reliability. Since buying my DTS in 2002-3, I've had too many bad experiences that's cost me $$$$$.

First, I had a loose spark plug that blew out the head one morning. That cost me just over $600 for a helicoil and new plug from the local Caddilac dealership.

Second, the wipers wouldn't quit running and shooting out water, there's another $200 in a wiper motor assembly replacement.

Third, water pump and thermostat, so another $200 in parts and labor.

Fourth, Evap Vent Solenoid for another $150 parts/labor.

Fifth, front pass bearings/assembly along with new rear calipers, all new rotors, and all new brakes with a fluid change for $1400.

Sixth, new tires (thankfully, I don't suffer from the high speed front-end shake like many have posted) at $700.

Not fixed yet: This loud whining problem. An intermittently leaking steering pump. Along with that, the DIC has been throwing Service Stability System and Service Suspension System for almost the last year, which I've had looked at and i'm looking at all new struts, front and back. OEM they're $700 each. Aftermarket through Arnott I can get it all done for about $1000...but I can't take any more of these breakdowns and problems that my local Caddy dealership wants $150/hr for and any other shop wants $65/hr.

Finally, if you have any more thoughts or ideas, please don't hesitate to post them. I'll try that isolation of those belt-run devices and see if that helps.


02-01-08, 04:26 PM
BTW, forgot to include that I don't want anyone to get me wrong...I LOVE my DTS. When I first bought it, I would go out to the garage every night and kiss the zebrano wood sterring wheel. Almost cost me a divorce, but I didn't care...loved the car. Still do...but I wish it had the life of a Toyota/Honda/Mazda (300,000 mi+) and reasonable parts costs like the Malibus or Impalas. If it did...or even close...I'd never get rid of it, and probably have bought one brand new just to say I was the first and only ever owner.

02-02-08, 07:07 PM
Just trying to be helpful here. Check the serpentine belt. :hmm:I had a buddy who complained about the same problem when we were changing the oil on his high mileage 02 Nissan Altima. I looked at the belt twice before I noticed just how bad it was. The second time was with a strong light and the belt not moving and his problem was obvious (lots of cracks perpendicular to the grooves and debris in the pulleys). I cleaned it up with shop rags and told him to get a new belt and to stop spilling oil on it in a nice joking sort of way (you said you had a leaking PS pump?) Anyway, he claims the noise is gone now. I remember when he demonstrated it for me it was a whirring silly noise that changed tone and intensity from idle through to different RPM. I attached an early TSB (Technical Safety Bulletin) from 1994 and a newer one from 2004 concerning complaints of the whir or chirp or grrr! noise. Taking tension off certainly will stop the belt and the noise too - although sometimes its even more obvious - Get a bright light and take a look is the belt dirty and greasy, etc. I included a video link showing a bad belt for reference.


Hope it helps.

02-02-08, 07:20 PM
Lots of cracks perpendicular to the grooves is normal (assuming that they do not go all the way through the belt of coarse). Chunks missing and debris in the pullies is not.

02-02-08, 07:31 PM
When the serpentine belt has cracks across it 1/10 of an inch apart but there are no chunks missing, it's at 1/2 life and is good for another 50,000 miles.

02-05-08, 02:07 PM
also check the belt tensioner mine made a loud wine hiss type of noise before I changed it. I also sounded like it was coming from the power steering pump.

02-12-08, 10:57 PM
Hey guys. Sorry about the late post. Been busy with tons and tons of snow and a broken tractor. I used that awesome trick with the garden hose. I found a short piece of broken hose. Stuck one side to an ear and worked it around the belt path. After about 10-15 minutes of checking, it was truly the idler pulley. I price checked all local competitors along with online. Rock Auto online has the pully at $25 versus O'Reilly's Auto that was at $41. I also found a Torqflo at Auto Zone for $16. I bought the $16 part because I don't know how much longer I'm going to own it. I thought I could do it myself, but found that I couldn't get a wrench down to that bolt head myself. I took it to a local shop and they did it in 45 minutes and charged me only $44 to do it. Was a steal. I went from a LOUD annoying whine to a nice soft quiet engine under the hood. Best money I've spent in a long time! Thanks for all the help!