Mechanics

THREE NOISES: 1) AC CLUTCH? 2) BRAKES? 3) BELT TENSIONER?

Hyundai Elantra

Dear 2CarPros:

I am the original owner of a low-milage 2001 automatic Hyundai Elantra, including ABS 4-wheel disc brakes with traction control.

The following three noises have bugged the heck out of me for almost the entire life of the car, but none of them have triggered a check engine light. My powertrain warranty is 10yr/100K, which still qualifies me for limited help, but not for much longer. Given that I have a paper trail documenting all of what I am about to describe, if not an answer to the possible cause of these noises, how would you suggest I handle the dealer during what is left of my warranty? I have already tried taking the car to other dealerships while under warranty but they refuse to help. After I took the car to an independent mechanic a couple years back, the originating dealership tried to pin a subsequent problem on the service I obtained elsewhere. I am at my wit's end and need your insights in order to get someone to listen. Personally, I suspect these noises are not as mysterious as the dealer would like me to believe. Rather, I get the feeling they are trying to run me out of my warranty. You be the judge. Do these sound like difficult noises to troubleshoot?

Here goes it:

• If I put the car into reverse and begin backing out of my parking spot, I hear a rattle from the AC. If I leave the fan running but switch off the AC while it is rattling, the rattling stops. When I re-engage the AC the rattling starts up again until I put the car in drive. When this first started about three years ago I heard this same rattle while in Drive, and it seemingly started after the right motor mount was replaced. Upon returning to the dealership, I was told it was just normal wear and tear to the AC clutch, and they did not suggest or offer to fix it (under warranty at that time). For a time the noise would appear intermittently in while in Drive or Reverse, however for the past year I consistently hear it while the automatic tranny is in Reverse (but no longer while in Drive). The second and last time I inquired about the problem at the dealer, a service rep stated I had been " negligent" in letting it go so long, and this despite the fact that I took it to them immediately after the noise first began (and have the paperwork to prove it). Question: Are they correct? Have I done it any further damage? Everything about the AC system seems to function normally, otherwise. When I first began hearing this noise, the car had less than 25K on the odometer and was still under the generous Hyundai factory warranty. I don't want to wait until I have a thousand-dollar AC repair bill, and was wondering if I need to replace the clutch to prevent a worse problem? If so, how much would be a fair price for that repair — or does it sound like it should have been a warranty issue?

• While idling at a stop I eventually hear a thumping sound from the rear underside of the car. If I adjust the pressure of my foot on the brake peddle, I can make the noise go away. I had hoped when the rear brakes were replaced the mechanic would uncover the problem, but they didn't (though I asked). Several years ago they told me my parking brake and muffler were fine, and on a test drive with the dealer mechanic at that time it was suggested that it may be a noisy fuel relay switch/selenoid in the gas tank. Sometimes the noise is faint (bump! Bump! Bump!), But other times it is loud enough to sound as if someone is trapped in my trunk and banging the interior with a rubber mallet to be let out (THUD! THUD! THUD!). I usually hear the sound while idling at one or more stop lights while out driving, so it is not difficult to duplicate (the mechanic mentioned above heard it). Rarely, but sometimes, I also hear this same noise after pulling into the driveway, putting the car into Park, pulling up the e-brake, taking my foot OFF the brake peddle and before turning off the ignition. People standing outside the car when it does this hear the thumping sound too. Question: Am I in danger of having the brakes fail? Is it possible the rear ABS are engaging when they shouldn't be, is an unrelated brake system component faulty, or might it be a part of the exhaust system?

• I hear a rattling when accelerating during cold weather. It sounds like a frog-in-the-throat in the engine (or pebbles tumbling in a plastic can). After leaving my car numerous times at the dealership and even having the factory rep out who replaced the right motor mount, thrust bearing washer and authorized a carbon cleaning of my valves, I am still at a loss as to what it was. I have had more than one mechanic indicate that I was hearing a tapping valve, but the dealer says my valve clearances check out (the lifters on this engine are not hydraulic, but set with shims). Usually the noise is gone within 15-20 minutes or so after a cold start in cold weather. Having read years ago in a discussion forum that the problem could be related to the tensioner on the timing belt, I begged for them to check the belt tension or replace the tensioner, but they refused to do so under warranty (said it was too much effort to get into that part of the engine for a " hunt-and-peck" situation, and that I would have to pay out of pocket). Well, last year I decided to have the drive belts replaced. The dealer claimed that while the car was 7 years old at the time, the water pump and belt tensioner didn't need to be replaced at the same time because my miles were so low. Nevertheless, the acceleration rattle is much improved now that the timing and engine belts have been replaced. Question: What explanation can you offer for why changing out the timing and drive belts seems to have almost entirely eliminated this cold engine acceleration rattle, which I began hearing when the car had just 150 miles on the odometer? I am relieved that the noise is considerably reduced since the belts were replaced, I just don't understand why the Hyundai rep went to so much trouble to replace the thrust bearing washer, authorize a carbon removal service and even change out the right engine mount if it was a timing belt or belt tension issue all along? In other words, does this sound like a case of incompetence on the part of the dealer/service rep or an honest mistake?

I realize I've submitted a 3-part question that is longer than those you normally receive. However, I really, truly need and will wholeheartedly appreciate your insights into what may be causing these noises. One of the reasons why the car has so few miles on it is because I cannot enjoy driving it when I hear all these odd noises. You are my last, best hope 2carpros, and if you help me get to the bottom of these mysteries I will be happy to make a donation!
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January 27, 2009.




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