Don't run the car hard until you find out what's wrong and get it fixed. I recently found out that low voltage can reduce the pressure from the fuel pumps and potentially cause the engine to run lean!!!
ok thanx.... i got the alternator and battery tested and they seemed fine but the battery light wasnt on when i got it testd but ike i said it only really happens at higher rpms... wat should i do now ?
no the car is completly stock..... no pullies not even exhaust it has 500o mies on everything ....... when it was tested the light wasnt comming on ..... i guess im gonna try to see if i can get it tested when light light comes on but its hard because it usually doesnt come on till about 4000 rpm
same thing happpened on my buddys 03 GT..i ended up testing the alternator and it was putting out 9.5 volts at 4k and above....after a week or 2 it stopped doing it, he never changed the alternator but i was almost sure that was the culprit, other than a slipping belt
I would go out and buy one so you are ready to fix it. I just bought a reman one from ford. There is a great write up on SVTPerformance about it if you are not mechanically inclined like me.
My car did the same thing and eventually the light stayed on...at which point you dont have far to go before your dead...especially at night.
Normally the signs of a bad alternator are the battery light comes on in dash, however, once you accelerate and get higher in the RPM range, the failing alternator will kick in and the battery light will go out, due to the acceleration makes the alternator work faster and gets it moving again...
So if you're car dies at 4k RPM and ABOVE....i would want to say that the alternator isn't the problem....its possible I guess. I've just personally never heard of that happening..
Usually a failing alternator will begin to work again at 4,000+ RPM...not start failing. Maybe i've just never seen an alternator fail like this before.
Be sure to let us know what you find. And after hearing what U.M. said, i'd look into it ASAP!!