My car vibernate violently while braking

A1)The viberation is extremely severe when car is still at the tranfic lights when brake is put on hard and the shift is at D.

A2)When I put the shift to parking. Then car sits quietly.

A3)I checked the pine and muffler. The pine is very rusty and broken.

A4)The car can't pick up speed, and sounds very heavy unless I step on gas pedal very hard.

Check vacuum hose to power brake unit for leaks, or if it is off.

lights when brake is put on hard and the shift is at D.

pedal very hard.

You probably have a warped brake rotor. If warped it will make the break pedal seem to pulse 'or' will cause the vibration you state. The solution is easy, take the rotor to an automotive machine shop and have it 'faced' and returned to true flat surfaces That you consume a lot of fuel (and have stated the above brake 'problem') incidates or suggests that you have a brake caliper 'hanging up" and not unloading. Next time you drive the car after a few miles, stop and carefully and with caution feel each wheel until you find one that is HOT ... that will identify which brake is malfunctioning - be careful not to burn yourself. (The heat caused by excess brake friction will cause a rotor to warp). The easiest is to entirely replace the brake caliper @ an aftermarket cost of ~$240.00 ..... or you can 'fiddle' with it by backing off the stroke limit adjustment screw - an adjustment that limits the free travel of the piston inside the caliper; then with the caliper dismounted from the wheel make a few attempts to make the piston travel it full stroke (use a C-clamp to prevent too much travel) and see if this doesnt break the piston free on its return stroke.

Hope this helps.

Sounds as though you aren't getting power out of all of your cylinders (likely misfiring, or "missing"). Check your plugs and wires (heck, replace them if you haven't done so in the last 20-30k miles), and do the other routine maintenance (tune up, etc.) that would have been due near this time (assume that the previous owner didn't).

The car is "lugging" when at low rpms at idle when engaged to the automatic transmission, but when the load is taken off the engine (putting it in park or neutral) the engine will idle faster, smoothing out the misfire.

You'll know when you've got things right...

Mike "Love My Miata" Verive snipped-for-privacy@mverive.com

lights when brake is put on hard and the shift is at D.

pedal very hard.

Thank mcben, MiataMan and Rich Hampel. Wonderful suggestions.

If you do get the sticking caliper to work, dont forget to use a high temperature silicone grease on the piston .... must be high temp

Subject: My car vibernate violently while braking

ACK! My old eyes actually read this post as "my car vibernate violently while barking :-) ~Cissy "Don't be so open-minded your brains fall out of your sock drawer" ?? :-D

Silly Cissy. You know that when bears vibernate for the winter they're asleep, and don't bark.

Lanny sezzz :)

Silly Cissy. You know that when bears vibernate for the winter they're asleep, and don't bark.

Oh yeah, huh...... ;D ~Cissy "Don't be so open-minded your brains fall out of your sock drawer" ?? :-D