, Salem, MA


January 26, 2013

Auto Scanner: Vacuum leak could be causing whine in GMC

Q: I have a 1998 GMC Sierra K1500 with 168,000 miles. It has a low-pitched whine like a blower motor might produce, but it is not the blower motor. Under the very slightest acceleration, in drive or neutral, it goes away. It is not affected by engaging/disengaging the A/C compressor. I have replaced both the belt tensioner and the idler pulley to no avail (both were well on the way out). The alternator was replaced about 10,000 miles ago with one that was rebuilt for Delphi. The water pump (Airtex, I believe) is about 30,000 old, and the power steering pump is original but does not whine under load. This whine is hard to hear outside of the cab with the hood open. It is really annoying in traffic. Should I remove the serpentine belt altogether and see how it sounds? Any thoughts?

A: I would not be surprised to find a vacuum leak under the hood that is causing this whine/hooting noise. The engine vacuum is the highest when the vehicle is idling. A slight change in the engine load, such as putting it into gear or raising the RPM, will indeed change the vacuum. One common area of noise that you describe is the vacuum rail that is bolted to the exhaust manifold. There is a little check valve on the line that can make just the kind of noise you describe. It may be helpful to smoke the engine to also find the leak.

Q: I own and love my 2005 Ford 500 Limited AWD with 3.0 engine and recently noticed the heated seats work fine and then don’t work at all for a period of time, then work again. Each seat seems to be independent. Example: Driver’s side will work but not the passenger side. The problem is intermittent but mostly negative, and more often they don’t work. Not sure where to start and wonder if this is something I can try to repair, or does it need to be brought to the dealer? Hoping I can troubleshoot myself, being a 75-year-old on a fixed income. Any idea what the cost would be?

Text Only | Photo Reprints

AP Video
After Fukushima, Japan Eyes Solar Power New York Auto Show Highlights Latest in Car Tech New York Auto Show Highlights Latest in Car Tech High-flying Tech Stocks a Concern for Investors "Heartbleed" Bug Puts Internet Security at Risk AP Tech Review: Samsung Galaxy S5 Toyota Recalls 1.8M Vehicles in the US Comcast Executive: 'Merger Not a Problem' Microsoft Ends Support for Windows XP Study: Airline Industry Complaints Drop in 2013 Study: Airline Industry Complaints Drop in 2013 Employers Add 192K Jobs; Rate Stays at 6.7 Pct Senators Press Barra About GM's Delay in Recall More Americans See Middle Class Status Slipping GM CEO Faces House Hearing on Recall NHTSA: GM Should 'Fix Vehicles Quickly' GM's CEO Testifies on Faulty Ignition Switches Owner, Families Share Cobalt Stories Jury Selection Begins in Apple-Samsung Case BMW Plans $1 Billion Expansion in South Carolina
NDN Video
Jabari Parker's Top 5 Plays From Duke Career Kourtney Kardashian Is a Bikini Babe More Manpower Than Ever Expected At 4/20 Rally Debunk'd: Miley Cyrus AIDS, Cheeseburgers Cause Cancer, Military Warning Bill Previewing the NBA playoffs Raw: Orthodox Christians Observe Easter Rite My name is Cocaine Raw: Space X Launches to Space Station Lohan Gets Candid About Her Sex List The 2014 New York Auto Show Meet Johnny Manziel's New Girlfriend Chelsea Clinton Announces Pregnancy Funny: Celebrating Easter with Martha Stewart and Friends Man Accuses 'X-Men' Director Bryan Singer of Sexually Abusing Him As a Teenager Man hit with $525 federal fine after he doesn't pay for soda refill Lea Michele & Naya Rivera Feuding? Jabari Parker declares for the NBA draft Singing Nun Belts Out Cyndi Lauper New West, Texas Explosion Video Swim Daily, Throwback Thursday
Comments Trcker