So while I was driving around last night, I noticed a pulsed vibration coming from what I think is the front wheels. It varies with the speed of the car, more frequent at higher speeds, less frequent at lower speeds, in sync with each rotation of the tire. I checked the tires, no odd things there, checked air pressure and still pulsing at correct psi. Maybe something to do with the brakes? Pulse is stronger when turning right than left.

I have no clue where to start looking or what I'm looking for. Cupped tire? Stuck caliper? Any thoughts?

 

Balance off?

 

If you don't have staggered wheels, then swap the rear tires for the front and see if that replicates your problem, if it doesn't then voila, 1 or your 2 front tires are bad.

Hope this helps...

 

Does the pulsing occur when you apply the brakes or when you are just cruising? If when applying the brakes, it is most likely warped rotors. If it occurs while cruising, you may need to get your wheels/tires rebalanced.

Do you have any abnormal wear on the tires? Or do you have aftermarket wheels that require hubcentric rings?

 

Raise the front of the car and carefully check each of your front tires all the way around. Check for a bump or bubble or flat spot that might be hard to see with the car on the ground. You could also remove the front tires to check them (even better). If there's nothing visible then check balance.

 

^ what he said.

Also, do you feel the vibration through the steering wheel, the chassis, or both?

 

Thanks for the replies. I feel it through the floorboard, not thru the steering wheel. Its not warped rotors cause I've been thru that 3 times now so I know what that feels like. OEM wheels are on it, but the tires are starting to get low on tread. Didn't see anything stuck in the treads and no wheel weights missing. Looks like its time to take off the wheels and do a more thorough check. Guess I need to invest in a floor jack and jack stands too.

 

My guess is it's something in the rear, not front. I'd venture to say that if it was in the front, you'd be feeling it in the steering wheel. Even a small imbalance is typically felt through the steering wheel first. You mention it's in the floor boards, so either it's not wheel related, or rear.

Good luck!

 

Check your tires. I'm thinking they are probably unevenly worn.

 

I had a similar problem which turned out to be rear caliper stuck. there was alot of brake dust on wheel.

 

Well - I've got a similar problem, but...

It only feels out of balance for the first mile or 2 after it has been parked for several hours. Example: leaving work today, I drive about 1/2 mile to the freeway (114) - and accelerate to @70mph. The imbalance feels horrible - can be felt in steering wheel. It slowly fades...and doesn't come back until situation occurs again (sitting for several hours - but NOT in my garage). AND - only at speeds >@65/70mph...

Wheels/Tires were just road-force balanced last week in an attempt to chase this issue.

Thoughts? Bad front tire? But then - why would it smooth out? Do the RE050's flat spot? Driving me nuts..

FYI - today's temp was @105 degrees as I was leaving work...so it's not like the tires were cold...

Sorry for hijacking thread...OP's problem sounds like an out of balance issue. I'd get a road-force balance on all 4 tires and see if that fixes it...

Thanks

 

That's just the tires deforming from sitting so long. It goes away because they warm up and true up again. Not a problem.

You may notice it more in colder weather too.

 

First you need to eliminate any suspension or brake problems. Worn suspension or brake components can amplify any tire imbalance or run-out problems.

Second, you didn't mention if this was something that grew gradually or came on suddenly. If the former, the tires may just be worn out. If the latter, see #1 above.

You might also take the car to a tire shop that has a Hunter 9700 balancer. These balancers also check for tire sidewall force irregularities as well as wheel runout and tire imbalance. Here's a reference on how it works:

http://www.tiremartpa.com/GSP 9700 features.htm

The tire may be in balance but still bounce due to variations in the tire sidewall force around the circumference of the tire. I have a 2001 Miata that exhibited the infamous "Miata 65-mph hop." I took it to Discount Tire and had this balance procedure done to the tires and it completely solved the problem. In essence, they find the stiff spots on the sidewalls and match them up with the low spots on the wheel runout and then do a dynamic balance. Once they finished the Miata, the two of the tires showed 0 pound sidewall variation around the circumference of the tire and the other two tires were one and three pounds. I think the tolerance for the Miata was 14 pounds allowable. I also had this done on my previous Saturn LW wagon with similar results. If you want to go this way, make sure the shop has the 9700 machine with the roller bar that presses against the tire during rotation. Hunter makes other machines that measure the runout of the tire with a laser; that checks for out-of-round but does nothing to check the sidewall force uniformity. Hunter's website has a dealer locater search:

Hunter GSP9700 Wheel vibration Control System solves wheel vibration and tire pull problems that balancers and aligners can't fix

Good luck.

 

I had that in an old Mercedes I had...with a set of Pirelli's. Didn't know the RE050's did that too. And yes- thought it was more of a cold weather problem...

 

Yes - I believe this is what they call 'road force' balancing. In fact if you look at Hunter's website - you see a picture of their balancing machine and it states 'Road Force' on the front...and that is what Grubbs Infiniti did..

Anyway - problem still persists after that balancing. I really do feel like it is what I call 'flat spotting'....the tire holds that 'deformation' from being parked for 8-10 hours...

anyway - that is my only theory for now!

Thanks