Would you like to play internet mechanic? Bonus points if you can recommend a mechanic or Hyundai dealer in Chicago.
December 4, 2009 3:09 PM   Subscribe

Would you like to play internet mechanic? My car is having problems, one involving the brakes and two mystery problems. Bonus points if you can recommend a mechanic or Hyundai dealer in Chicago.

My car is a 2004 Hyundai Elantra Sedan. FYI, I have 17,000 miles on the car. I don't know if this is important, but I read somewhere that not driving your car a ton was a bad thing.

Brakes - The amount of pressure I have to apply to the brake pedal varies a lot. Sometimes I only have to press the brake pedal down a little, sometimes I have to press it all the way to the floor, sometimes it's anywhere in between those extremes. This first started happening some months ago. I thought it was because of wear on the front pads so while I was at the dealer for a different issue I had them look at the brakes. They said the front brakes were fine but the rear brakes needed to be adjusted. After that, it was okay for a while, but the amount of pressure needed started varying again. So, I took it back to the dealer and said "My rear brakes need to be adjusted". They acted like I was speaking Greek. They looked at my brakes and said the rear brakes were at like 50% but didn't say anything about adjustment and offered to do some work on my front brakes for $250.00. That seemed quite expensive so I declined and took it to Meineke. The mechanic at Meineke said my front brakes were fine and that my rear brakes needed to be adjusted. So they worked on them and the brakes worked okay for a bit but now they are acting up again.

So, what does it mean that the rear brakes needed to be adjusted? Why doesn't adjusting them keeping the problem from reoccurring? Am I looking at having to get new rear brakes? Any idea how much that would cost?

Mystery 1 - In October, I took the car on the expressway for the first time in some months, and once I hit about 60 mphs it started shaking like it stole something. I don't know if the whole car was vibrating but it felt like it. The steering wheel was shaking so much that my entire forearms were vibrating. Any clue what this could be about?

Mystery 2 - When I turn the steering wheel to the left, there is this noise, it kinda sounds like metal on metal. But, it's not constant, it's noise-silence-noise-silence, like a record skipping. Sometimes its loud, sometimes it's quite soft. This only happens when the car is in motion and it never happens when I turn the steering wheel to the right. Any clue what this could be about?

I used to take it to the dealer where I bought it for service (which only involved getting it inspected every year and routine maintenance, I haven't had any problems with this car prior to the ones listed above), but I'm reluctant to take it back there since they acted like they had no idea of what readjusting the brakes meant when they had done it previously and suggested brake work that it seems I didn't need. So I would appreciate any recommendations for a decent mechanic or Hyundai dealer in the Chicago area.
posted by nooneyouknow to Travel & Transportation (14 answers total)
Not a mechanic at all, just have dealt with many car problems.

Mystery 1 to me sounds like engine mounts, or possibly an incorrectly balanced tire. If it is a tire then it's cheap (dollars or free depending on where you go) engine mounts cost a lot more.

Mystery 2 possibly wheel bearing. If it is a bearing that can be dangerous and you need that fixed asap.
posted by WickedPissah at 3:42 PM on December 4, 2009

I believe (unless you have the GT model) you have disc brakes on the front and drum brakes on the rear. The drums need adjusting; the discs don't.

Try applying constant firm pressure to the brake pedal when you are parked, and see if the pedal slowly descends. In this case you have a leak in one of the brake cylinders. When you pump the brakes, the pressure comes back up, so you only notice under steady firm pressure. That likely accounts for the variation. Check the level of brake fluid in the reservoir, also.

Mystery 1 sounds like worn tie rods or ball joints. Get those checked, pronto.

Mystery 2 could be related to Mystery 1, or it could be a loose flap of metal or plastic in the wheel well. You really need the car on a hoist to check all these out.
posted by weapons-grade pandemonium at 3:46 PM on December 4, 2009

Brakes as a system are both hydraulic and mechanical. When you depress the brake pedal with your foot, you are actually activating a piston in your master brake cylinder under the hood. This cylinder, in turn, pushes a proportional amount of brake fluid to the individual brake cylinders in each wheel. Depending on the type of brakes your car has, these either squeeze your brake pads against a disk or spread out a pair of brake shoes against the inner surface of a brake drum.

This system can become compromised by air in the brake lines. It only takes a small bubble of air to screw things up. "Air in the brake lines" is fixed by having the brakes bled. Prices vary, but a place that specializes in mufflers and brakes may charge you $35 - $60 to bleed the brakes. Varying brake pressure is one of the symptoms of air in the lines, but varying pressure can also have other causes, so don't jump to any conclusions just yet.

The system can also become compromised and display varying pressure of the brake master cylinder is failing. Failure in this part usually occurs when its cylinder walls become pitted, allowing brake fluid to bypass it's piston.

Individual brake cylinders on each wheel can fail in the same way as the master cylinder.

My suggestion is to take it to a good mechanic and explain that the system exhibits varying pressure, and you suspect either air int he lines or a failing mater or wheel cylinder s/he can check it out at that point and should be able to pinpoint the problem.

The vibration at speed is likely due to a wheel that isn't balanced. The same shop that checks out your brakes can rebalance your wheels.

Finally, if the wheels aren't out of balance, the vibration could be caused a failing control arm ball joint or CV joint. Those are parts that fail in obvious ways and their inspection would/should be part of any general brake system inspection.
posted by mosk at 3:58 PM on December 4, 2009

i concur with the above description mosk made about air in the brake line.

mystery 1 sounds like an out of balance tire. not a big deal. fixing it will improve mileage.

mystery 2 sounds like a cv joint problem.

i use an independent mechanic for my hyundai in addsion. mefimail me if you want that contact info.
posted by lester's sock puppet at 4:42 PM on December 4, 2009

Mystery 1: Tire balance. Since you don't drive your car much, your tires could be dry rotted or have developed flat spots. Both of those conditions will contribute to imbalance or a tread surface that generates vibrations.

Mystery 2: Do you have to be in motion to hear the noise or do you hear it with the car stationary and turning the wheel as in a parking maneuver?
I think it could be a strut bearing. That's a friction surface at the top of the strut where it mounts to the frame that allows the wheel assembly to rotate.

17,000 miles is EXTREMELY PREMATURE for anything serious to have happened. If that car needs a wheel bearing, tie rod, ball joint, or CV axle this young, I'd have to guess that you were involved in an accident. That being said, if the car feels unsafe or uncontrollable, get it checked out. Front end work is pretty easy, gravy work for a shop. If something was wrong, I'm sure someone would have suggested it by now. But, better safe than sorry. Still, I'd be amazed if anything was seriously damaged at that mileage.

Now, on to brakes.
Disk brakes are self adjusting. Every time you press the pedal, the brake master cylinder generates hydraulic pressure that acts on a piston in your brake caliper. That piston applies pressure to the brake pads which create friction against the disk and the car slows down. Every time the brakes are actuated, a little bit of their surface is removed and the piston comes out a little bit further each time. It's retracted, almost imperceptibly by a seal that surrounds the piston that prevents brake fluid from escaping. So, that piston inches forward slowly and the flexing of the seal minutely retracts the piston.

Rear drum brakes are quite different. They're comprised of two half-moon shaped brake "shoes" that face away from each other and are pressed against the inner faces of the brake drum to slow the rear wheels. They're then retracted by a system of springs. The hydraulic mechanism in the drum brakes is referred to as a "wheel cylinder" which is just two simple little pistons that actuate in opposite directions and press on the shoes. They don't self-adjust like a caliper and there's a ratcheting mechanism in the drum brakes that's supposed to help take up the clearance as the shoes and drum wear from use. Those drum brake adjusting mechanisms don't do an awesome job and periodic manual adjustment is required.
posted by Jon-o at 5:12 PM on December 4, 2009

Thanks, everybody.

Mystery 2: Do you have to be in motion to hear the noise or do you hear it with the car stationary and turning the wheel as in a parking maneuver?

Has to be in motion. Have turned the wheel when the car was parked and the car was on and when the car was parked and ignition off and didn't hear anything.
posted by nooneyouknow at 7:13 PM on December 4, 2009

What's most likely, given your low mileage combined with the age of your vehicle is this:
There's a little corrosion or a high spot on your brake disks. When you turn the steering wheel, the brake pads shift a little bit in their carrier so that they're just a gnats ass away from the brake disk, or touching it slightly. When the corroded spot or high spot comes around as the wheels rotate, the contact of the pad and rotor is audible to you. Like a metallic and faint shhkkirsh-shhkirsh-shhkkirsh, right?
posted by Jon-o at 8:00 PM on December 4, 2009

Like a metallic and faint shhkkirsh-shhkirsh-shhkkirsh, right?

Yes, but occasionally, usually just after I start the car in the morning, it's rather loud.
posted by nooneyouknow at 8:48 PM on December 4, 2009

i concur with the above description mosk made about air in the brake line.

mystery 1 sounds like an out of balance tire. not a big deal. fixing it will improve mileage.

mystery 2 sounds like a cv joint problem.

posted by davejay at 10:04 PM on December 4, 2009

Oh, and if you've lost the CV joint at such low mileage, it's because the boot is torn and it's rusted, so you're gonna need a new one. It happens. There's a chance -- but very small -- that the vibration is from the CV joint as well, but a wheel balance is cheap and effective, so do that when you get the CV joint replaced (if that's what it turns out to be.)
posted by davejay at 10:06 PM on December 4, 2009

usually just after I start the car in the morning, it's rather loud.
That's because there's some corrosion on the brakes from sitting over night. Also, all the parts are cold and they're probably binding just a little bit.
My car does exactly the same thing.

If your 2004 Hyundai with 17,000 miles needs a CV joint or somehow has air in the brake system, I would be shocked and amazed. Air isn't going to get into your hydraulic system unless A) the system has been opened or B) there's a leak. There's no reason for your brake hydraulic system to have been serviced at such a low mileage and if there was a leak, you'd have trouble stopping the car and the big red BRAKE warning light would be on all the time.
I'd also be surprised if none of the people inspecting your brakes noticed the ripped and deteriorated CV boots. That's some good gravy work that they shouldn't be passing up. Now, I have seen those boots deteriorate from age, rather than wear. But we're talking ten year old cars in that situation. The CV boots should still be intact. And your description of the noise also doesn't match up with CV joint noise. Instead of noise-silence-noise in a regular way, they grind, clatter, and growl when they're worn.

I think you're experiencing classic "I don't drive my car often" symptoms. Your tires are in probably crummy shape from sitting and likely under-inflated, causing your highway-speed vibration and your brakes have some corrosion resulting in that metallic noise you're hearing.
posted by Jon-o at 5:00 AM on December 5, 2009

Cartalk (the NPR show) is your friend for this. It should be mandatory that any "Find me a good car mechanic question" should start at their Mechanics files.
I've found three great car repair places over the last 7-8 years this way.
I fed in 60601 with a 50 mile radius and The Auto Clinic came up with great reviews.
posted by filmgeek at 8:26 AM on December 5, 2009

I've had good experiences with Ashland Auto and Tire. You can look them up on on Yelp.com.
posted by specialnobodie at 2:29 PM on December 7, 2009

10yr/100k mile warranty. Take it to the dealer.
posted by Dorri732 at 12:29 PM on March 16, 2010

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