Bajabilly1

Just got this mustang 1998 GT 4.6 V8 Automatic. Actually it was left to me by a family member who just passed away. The last Mustang I had was a 1971 Mach 1, back when they were easy to work on, wish I still had it. I know nothing about this one. Passed smog fine has auto trans seems to shift fine and the fluid seems clean, pedal to the metal it moves out! shifts great. 178K on it, runs great. HOWEVER Some times when your driving and it's in Drive and you come to a stop the rear wheels start burning out (spinning) the engine doesn't seem to rev up (or I didn't notice due to the weird situation) so I am baffled.Never had a car do this.Thanking anyone for their help in advice of where to start looking. Did it at the gas station and once at a stop sign, and again today when I pulled over for an emergency vehicle. seems like the tyranny starts whining when it does this. This is kind of a scary thing to happen. Asked a mechanic what it could be and he said I've never heard of something like that.( neither had I) But then he said perhaps the throttle body is going bad? any help would be appreciated.

Z28KLR

I assume engine speed increases along with this? Have a hard time imagining it makes enough power at 750 rpm with the brakes applied to spin the tires....

This is gonna sound dumb, but first thing is make sure your right foot isn't pressing both brake and throttle pedals at the same time. Yes, I have done it before - pressing brake pedal near the lower right corner of the pedal at a stop and found my foot making a bit of contact with throttle.

Check the throttle cable and throttle body, make sure nothing is sticking anywhere. Beyond those two ideas though I'm not sure. Cruise control deactivates when you apply braking, so unless it has gone rogue on you and self activating (which I've never heard of on these cars) then safe to say it's not that. IAC (idle air control) valve could be a remote possibility, but usually the problem with those is low idle speed or won't idle at all. And even then, it would have to be raising idle speed somewhat significantly in order to powerbrake the tires.

Urambo Tauro

+1 ^

Speaking of the brakes, you might want to check them out too. Particularly the rear ones. If they're not wearing out prematurely from all this wheelspin, they might not even be functioning.

cbdallas

If your car is able to spin the rears at idle, your rear brakes aren't working at all. If it was truly idling, have that checked immediately.

But do be careful that you're not hitting the gas along with the brake. Been there...it's a strange sensation.

Bajabilly1

Thank you cbdallas, I suppose it could be we both are hitting the brake and gas at the same time. then the rear brakes must be bad as you said I will check them. thank you for the advice.

WJL

Does the car have ABS?

Bajabilly1

Seems the matt was catching the gas pedal, well it was jammed up under it so I took it out and o far no more problems. I hope the problem is solved. also used some cable lube on the throttle cable and linkage. Thank you everyone for your help I know you all thought I was nuts. I thought my wife was too until it happened to me. never thought to look at the matts.
Bajabilly

Urambo Tauro

Glad it was a simple fix after all! If those mats are moving around on you, check to see if they have spikes on the bottom for the carpet, and if those spikes are any good. There are also anchor kits that you can buy.

Oh, and don't forget to check those rear brakes. All that spinning while stopped probably hasn't been kind to them.