Elusive Front End Vibration

At around 65 MPH, the front end will vibrate causing the sterling wheel to shake. I’ve had the car checked by three different mechanics and they cannot reproduce the vibration. Yet, without fail, it vibrates at least 80% of the time I drive it on the interstate. I feel like the guy with the singing frog on that WB cartoon. Nothing wrong with the transmission and the tires are OK. They have 27k miles and were recently rotated and balanced. Months before the vibration, the front end was making a humming noise at 70 MPH and felt as though something was slowing it down. On one isolated event, I stopped and parked the car briefly. When I started it up an put it in drive, it would not budge. The transmission was engages, but the front end was locked up. I turned it off, waited and tried again several times, and suddenly the problem disappeared never to happen again.

Do You Know The Model-Year Of This Toyota Corolla And The Approximate Number Of Miles On It ? Diagnosing Is Hard Enough To Do Without Access To The Vehicle. The Information Could Prove To Be Helpful.

Thanks,
CSA

These Symptoms Make Me Wonder If You’ve Got A Brake Caliper Sticking. That Could Explain The Locked-Up Front-End And A Dragging, Overheating Brake, And The Steering Wheel Shake.

I’d drive and then stop a check the front brake tempratures, preferably by “shooting” them with an infrared, non-contact thermometer.

This didn’t start shortly following a brake job by any chance ?

CSA

2006 CE with 99700 miles.

Forgot to mention. It just had a brake job.

On the brake job, they turned the rotors and replace the pads. Would they have noticed the brake caliper? As for the lock up. It happened only once last May. At that time, I was getting an intermittent loud humming noise with some vibration. By intermittent, I mean that sometimes at 70 mph it would do it and sometimes not. It would go a whole week without doing it. Now, it almost always vibrates, but never when I take it to a mechanic. I recall that when I took it to the last two mechanics, the outside temperature was lower (upper 70s, lower 80s) as compared to our summer temperatures that run as high as 105. One mechanic drove it while it was raining. The other drove it just before it rained. When it was humming, a friend of mine, who is a mechanic, suggested that the wheel bearings may need replacement.

Nice work CSA!

The manifestations should be obvious on a lift. Discoloration of the affected disc or/and uneven pad wear.

It started before the brake job and continued after the brake job.

One mechanic put it on the lift and could not find anything wrong.

What I find interesting is that the front end in not out of alignment and the tires show no uneven wear. Although my knowledge of car repairs is that of a novice, I think I can narrow it down by process of elimination. It is not the transmission, not the tires and it is not the brakes, so something must be wrong with the wheels. I’m leaning towards wheel bearings. However, would a wheel bearing problem be intermittent? Perhaps temperature has something to do with the intermittent occurrence. Does this make sense?

I Still Wouldn’t Rule Out The Brake Caliper(s).

I’ve had them stick before. Here’s what I do to check on them. I drive the car for several miles (rural area) without touching the brake pedal to give the rotors time to cool. I coast to a stop while going uphill and pull to the shoulder (when no traffic is present). Just when the car stops I put it in Park.

I have an infrared non-contact thermometer that I shoot through the spokes in the wheels and read each rotor’s temperature. A hot one indicates a dragging brake caliper / pad(s). I’d try something similar before ruling out brakes.

Wheel bearings tend to make noise, like what you described, but will get noisier as they get worse (and they will worsen), not quieter. Wheel bearings usually make noise, not a shaking steering wheel. Wheel bearings should be fairly easy for a mechanic to check. Sometimes running the car on a hoist is necessary to find which front bearing is bad. You can try taking curves right and left when the noise is present. A bad bearing will usually be noisier one way and quiet down the other way.

CSA

If it’s not brakes, it could be a bad tire. Sometimes a tire will develop an internal flaw, like a partial separation of the different layers of rubber and metal wire, that can’t be seen from the outside, and does not show up on balancing. Try switching the front and rear tires.

Thanks a lot guys. How does the mechanic tell if the tire is defective? I’ll have my mechanic check the calipers as well.

Usually A Bad Tire Can Be Spotted Either On-Car Or On A Wheel Balancer By Holding a Device Such As A Screw-Driver Blade Near the Tire’s Tread While It Spins.

Compare the tires and get a feel for what a “normal” amount of lateral and radial run-out looks like. They are usually not perfect. Sometimes a tire tread moves side-to-side (lateral) and sometimes a tire develops a high or low spot in the tread and tends to move up and down (radial) to an excessive degree.

When a bad tire is detected, one must be sure it’s the tire and not the rim. It’s a good idea to check the run-out of that tire’s rim, too.

Sometimes when a tire is quite bad you can sometimes feel one end of the car move slightly side-to-side even at parking lot speed going straight ahead.

Some shops have expensive Road Force Balancing machines to troubleshoot “Elusive Front End Vibration.”

Link: http://www.coshoctontire.com/balancing.htm

CSA

How could a bad tire intermittently lock up a car so it wouldn’t move? In my opinion it can’t be anything but the brakes.Could be calipers, collapsed hose or master cylinder.

I was thinking about the brakes and missed the complaint about locking up (once, I think). Even if one wheel was locked, the other should have spun, I think. Could a stuck caliper really keep the car from moving? That sounds like a transmission problem. Since it only happened once maybe it was unrelated.

If the tires were rotated and the vibration didn’t change, then it is unlikely that the problem is realted to tires or wheels. More likely it is something else - trans or brakes,. CV joints?

Problem solved. The master cylinder had to be replaced. Thanks for help!

I am always happy to see follow-up reports so thank you very much for letting folks know what ultimately happened.

But I do have to say that I am struggling with how a bad master cylinder was producing a front end vibration. Are you sure about the terminology? Or did you get an explanation for why a bad MC would produce front end vibration? I’m curious.

The mechanic did not know for sure it was the master cylinder. He first replaced the hoses and it seemed like the problem was solved, but then on a test drive, the front end locked up. He replaced the master cylinder and the problem completely disappeared. The vibration must have been the brake pads rubbing on the disks which would explain why I needed to get my rotors turned and my brake pads replaced. Since I’m no engineer, I have no idea why a faulty master cylinder causes the brakes to be deployed. The mechanic gave some explanation which I forgot. It sounded logical. All I know is whatever they did worked. I have had good honest, prompt, affordable service from them in the past, so I trust them.