Steering wheel violently shakes occasionally

I occasionally experience steering wheel vibration no matter what speed I’m traveling. It starts out as a small shake and eventually becomes nearly impossible to hold onto the steering wheel. On two separate occasions, the brakes have gone out.
The car has passed PA state safety inspection and I have taken it to 3 different mechanics and no one can figure out what the problem is. I have had new tires and spark plugs installed, keep up with regular oil changes, etc.
Please help!

What kind of car? Need year, make, model and engine size/type.

2004 Toyota Corolla S, 4 cylinders, 1.81 l engine, 240,000 miles, manual transmission…

Now would be a good time to stop driving this car until the issues get sorted out. It seems apparent that it isn’t at all safe to drive. Even if you are willing to take some risks, don’t take them on behalf of others on the road.

To get help you need to clarify some things. First, what kind of car are we talking about (year, make, model). How many miles are on it?

Having the brakes go out and having the steering wheel vibrate are typically two completely different things. So please specify what you mean by having the brakes go out.

Does the steering wheel vibration have anything to do with applying the brakes? How old are the brakes (pads, rotors, etc.) Alternatively, does it have some connection to acceleration?

What kind of mechanics are we talking about? Hopefully you don’t mean “mechanics” at corporate chain places (e.g. quickie lubes, brake/muffler shop franchises, etc). Ask around and find your best locally owned, independent shop that specializes in front end/alignment work.

Either that or cut back on the morning coffee.

When the brakes “go out”, it feels like the brake pedal is loose and I have to jam the pedal all the way down for it to eventually stop. After a few hours of not running the car, the brakes are back to normal. This has only happened a couple of times, but needless to say, it’s pretty scary…
The vibration happens when I am just driving along (even on cruise control) and it just starts shimmying to a full blown shake. It eventually goes away, but sometimes comes back during the commute.
It doesn’t matter how fast or slow I’m going, if I’m going up a hill or if I’m on a flat road.
I’ve taken it to 3 reputable “non-chain” mechanics (I’ve done my research).
I’m so close to just buying a new car, but I’d rather not have another car payment right now.

There are so many things that could be the cause of our problem, but most of them should have been caught by a safety inspection.

There is one thing that can be difficult to detect and that would be excessive power steering hydraulic pressure. It causes the power steering fluid to get very very hot and then the steering goes wanky. Low PS fluid level might do this too, but I have seen it when the return hose on the system gets plugged up.

On indication of this is that the problem does not appear until you have driven some distance, and then it gets progressively worse.

The reason we ask for the year, make, model is that some people here have access to TSB’s and they maybe able to see if one has been issued for this vehicle.

Do follow cigroller’s advice and get this checked out asap. It can get very dangerous.

I think that you have two completely different problems. One is a failing brake master cylinder which is what occasionally has your brake pedal on the floor. The other is going to be in one of those front end issues that keith mentioned - wheel bearings, tie rods, ball joints - something of that nature. I don’t know a thing about excess power steering pressure so I can’t say much there - except that if it is occurring your PS fluid is probably toasted. Pull the cap off, look at and smell the fluid. If its black & smells burned that’s certainly something to look at.

None of this is safe.

Okay, thanks Keith and Cigroller. I’m going to take it back to one of my 3 mechanics and have them check those items out (if they haven’t already).
Thanks again!