Muffled Machine Gun Noise from the front-end

I have a beloved '93 Toyota Camry Station Wagon that has 260,000 miles on it.



Since April of this year I have noticed a sound similar to a muffled machine gun, da,da,da,da,da,da…coming from the front end of my car. The sound is most noticeable when cruising on a downhill (at interstate speeds-70mph) with no gas or braking -OR- occasionally on a straight away with no gas or brake. Also when I let the car decelerate from 70 to 40 I also get some violent shaking out of the front end like two football players shaking the front. The sound does not seem to occur with acceleration or braking, which leads me to believe it is suspension related.



I wonder if the wheel bearings in the front should be replaced. I understand if these are going bad it can allow vibration between the rotor and caliper. Note: The vibration ceases once I apply the brakes.



Also would a strut malfunction cause any of the above noises and symptoms?



I don’t think it is a tire problem because the tires have been balanced and rotated (along with an alignment) when the lower support arm bushings were replaced 6 weeks ago.



Cheers to all CarTalk fans everywhere,

-brad

I think you should take it somewhere (not a chain like Midas if you can avoid it) and have ALL the suspension and steering components checked out. There are several things that can cause a shudder like you describe.

I am going to guess two things. That suspension has to be looked at an corrected if you don’t want to lose control when something totally breaks. I would look for something like some loose floppy insulation or even something like a vacuum hose that may be flapping in the wind.

If it weren’t for the shaking, I’d guess that it was a loose plastic spray shield. The fasteners for those things have been known to rust off or fall out after a decade or two. With the shaking, I’d guess a wheel bearing, tie rod end, ball joint, tire, or strut mount. None of those is anything you want to mess with. If you aren’t knowledgable enough to check them yourself, drive the car at a safe speed (10 mph or less) to a competent mechanic and get the front end checked out.

I can’t believe you have been driving 70 mph since April with what you think is a bad wheel bearing. Are you waiting for a front wheel to come off to confirm your diagnosis?

By the way, my guess would be a bad c-v joint.

One possibility for the muffled machine gun sound is a loose or cracked exhaust manifold, or another loose connection in the exhaust system near there.

I agree with those who say you must get the front end shake diagnosed and fixed and now if you intend to drive the car. If that shop that replaced the lower arm support bushings is thorough, they would have test driven the car after ther work. Sometimes it’s the driver who has to stay on top of this kind of situation and find someone who can do the work.