Car pulsates when braking

[Bob24]

I have noticed my car pulsating quite a bit when I brake. The higher speed I brake at the more the car pulsates. Conventional wisdom tells me that the front rotors are warped.

However, the car only has 27,000 miles on it. The place I bought it from said that they had the brakes done prior to me buying it at 20,000 miles. I am guessing that they just had one set of brakes done. When I had a BMW, an indicator light would come on if the brakes needed attention. Apparently the Infiniti isn't equipped with that.

I think I know the answer to this question already, but will the rotors be covered under warranty if that is the issue? I am guessing not.

Another issue that I am wondering about is that the front upholstered trim piece that runs from the dashboard up to the top corner of my passenger window is rattling. I noticed that the previous owner or maybe a repair shop placed a makeshift wedge in between the dash and the trim piece to lessen the rattle.

I already had this very same piece replaced on the other side when I bought the car since it had a bad cigarette burn on it. I am wondering whether or not they would replace the pillar trim piece under warrantly as a poor fit and finish item?

[EniGmA1987]

The stock rotors are known to warp easily on the Ms. Most likely you are braking hard enough that it warped them and now you have that pulsing feeling. I doubt the rotors are covered under warranty, and if they arent I would get some nice aftermarket rotors that dont warp as easily. I got some TriNet rotors for really cheap and that have been great so far, and they havent warped at all yet and I brake fairly hard sometimes. All these bad drivers in So Cal http://www.trinetmotorsports.com/

[szh]

I would strongly recommend doing a good balance on the wheels first - before replacing the rotors ... quite often, the wheel imbalance causes vibration that feels like the brakes are going.

Z

[06M35Sport]

My car did the same thing when I bought it. It pulsated and it was the rotors. All they did was turn them and they are fine now. I will probably get some better ones when I have to replace them due to what I just read about them being known for doing this. Mine were not covered under the warranty.

I would definitely ask about the pillar being replaced under warranty. They were real quick to replace anything I thought was faulty under warranty. This gives them a job to do and they get paid from the warranty company so its money in thier pocket to replace these things. I would ask and I think you will find out they will replace it for you. If for some reason you do have to pay for one let me know how much. I to have a cigarette burn in mine but did not have them replace it when I bought the car. I wish I would have, but it really isnt that bad and not even noticable. I actually had to look closely at it to make sure of what it was. There were no other signs of smoking in the car and it smells new and the air doesnt smell like smoke, so they must of had one of those crazy I will smoke one in the car moments and oops I burned it so they didnt do it agian.

[jbillion]

Szhosain,

Can you explain more about the wheel balance? Is this the same as having the tires mounted and balanced?

[nadzak]

Could be one or a combo of the following three: 1. Wheels need balancing - if this is the case, however, you would probably notice the steering wheel shaking at least a bit when driving between 55-70 mph.2. Warped rotors - most likely not on your car due to the low mileage, but if yes, then need to replace them.3. Need brake service - Most likely scenario, so rotors need turned, not a big deal. While there, do a tire rotation and balancing and you get a brand new smooth ride.Enjoy

[szh]

Szhosain,

Can you explain more about the wheel balance? Is this the same as having the tires mounted and balanced?

Basically, yes. But, if all you are doing is a re-balance, then you do not need to dismount the tires - cheaper that way. Many tire places will re-balance free for the duration of the tire tread if you buy the tires from them too.

In some cases, getting a "force balance" (special equipment needed and the better tire places have the Hunter system for this) done is the best way to go. This puts a proper load on the tire while doing the balance and gets the most optimal results.

Z

[Double E]

The indicator light for the brake system is not designed to tell you when the rotors are warped. Brake fluid, electronics and perhaps pad life, but I don't think any car has a warped rotor warning system built in.

I'm thinking I have the same thing going on however....I did some hard braking with my new EBC slitted & dimpled rotors awhile back (just showing off) and since then, I'm mad shaking from anthing above 50mph.

It could be balance but i'm thinking I warped them....

Any idea if those types of rotors can be resurfaced?

[fiveliterbeater]

I would strongly recommend doing a good balance on the wheels first - before replacing the rotors ... quite often, the wheel imbalance causes vibration that feels like the brakes are going.

Z

those vibrations you are talking about, happen only when the car is driving and not under braking. that would be a car that has wheels out of balance. he mentioned that the vibrations happen only during braking. indication of warped rotors.

[szh]

those vibrations you are talking about, happen only when the car is driving and not under braking. that would be a car that has wheels out of balance. he mentioned that the vibrations happen only during braking. indication of warped rotors.

I understand your point ... but I have specifically seen "vibration when braking problem" be cured with a good re-balance of the tires. On my car.

I recommend as a thing to try (can be zero cost if you get it done at the place you bought the tires) before spending the money on replacing "warped rotors".

Z

[New2Import]

Vibes while braking can also come from not properly putting the correct torque to the lugs or off balance having one or two lugs too tight. They have plastic ring shims that can cure this kinda like bake shims for your brakes. I can only see warping the rotors if they get really really hot then a quick cool down like in the rain or you wash you car right after you drove it really hard.

[jbillion]

I'm getting an alignment and a balance on 6/15 at Infiniti. I purchased my tires from Tire Rack, so no luck on the free balance.

[tigerclaws1318]

You should take the wheel off and inspect the rim for any bend due to hitting deep potholes. When I went to get a nail removed from my rear tire the tech told me the rim has a slight bend from probably hitting a pothole.

Always have the tires balanced right so you dont get any sort of high speed vibration from the steering wheel or brake pedal.

Also retorque all the bolts holding the caliper bracket and caliper itself making sure all bolts are nice and tight. A loose caliper can cause all sorts of issues from pulling to vibrations.

Thats all I can think of besides resurfacing the rotor or just replacing it.

[szh]

Vibes while braking can also come from not properly putting the correct torque to the lugs or off balance having one or two lugs too tight.

Agreed!

After I get my tires balanced or if they are off the car at any tire place - or even the dealer - when I get home, I loosen the wheels with the lug wrench, then take my trusty, calibrated, Sears torque wrench and set all the lug nuts to 85 lb-ft myself.

Z

[szh]

The indicator light for the brake system is not designed to tell you when the rotors are warped. Brake fluid, electronics and perhaps pad life, but I don't think any car has a warped rotor warning system built in.

I'm thinking I have the same thing going on however....I did some hard braking with my new EBC slitted & dimpled rotors awhile back (just showing off) and since then, I'm mad shaking from anthing above 50mph.

It could be balance but i'm thinking I warped them....

Any idea if those types of rotors can be resurfaced?

Slotted and drilled rotors (I have to admit that I have never seen dimpled rotors) are tougher to resurface, but they can be done if care is taken. The lathe has to be turning slower than usual, and most places will charge extra for resurfacing these.

Z

[Bob24]

I got the car back today and they resurfaced the rotors under warranty since I had plenty of pad left. Had the pads been worn to below 50% it would have been on my dime for $289.

When I had my tires put on at Tires Plus (the kings of the upsell) they told me that my engine belts were shot and had chunks out of them. I had the dealer look at these as well and lo and behold the belts were actually shot. Kind of surprising with only 27K on the car. That set me back $195.

The 3rd issue was a rattle from the right side interior A pillar trim piece. They found the rattle and re-insulated the piece and the rattle is gone.

Overall I am happy enough with how things turned out.

[EniGmA1987]

you can buy a full set of nice performance rotors for less than that...

[dunkmastrjay]

I bought my 06 m35 with 24k on it. Had same issue, thought it was rotors. The car needed new tires anyway. So got the Falken 452's, turned the rotors, alignment. This seemed to work for about week. Then got the car on the highway, had to brake at about 80mph and it started doing the same thing again. So I just upgraded to the Rotora slotted and drilled rotor set. Still having the same problem, rotated the tires, same problem. I have checked the torque on the lug nuts, they were in spec. To say the least I'm pissed. I heard this could also be suspension related. Does anyone have any other ideas. Please help!!!

[dunkmastrjay]

Did you ever find out anything on your brake trouble?

Thanks,

jeremy