Hello. I just bought my first car, a 1996 TL 2.5 with 91,000 miles. I bought it from the first owner who meticulously maintained it and just gave it a 90,000 mile maintanance (belts,oil,transmission flush,water pump). As far as I know the car is in excellent condition mechanically. I just took a 300 mile trip from Los Angeles to Santa Barbara. Going there had no problems. Coming back is when the problem started. There was heavy traffic so I was constantly braking. After about 20 minutes of braking I heard a kind of knocking noise from under my feet. It wasn't loud but it was noticeable. And it seemed to happen every other time I braked. When traffic cleared I stopped hearing it. The next day I drove about 15 miles and it started happening again when I braked. It doesn't happen every time I brake but sometimes. I don't know what it could be. If it helps it happens when the AC is on and even when it is off. Also I didn't know I had to put premium gas in it. For about a week I put regular and mid grade. The engine seems to be doing okay. Not sure if it is related but I thought I should throw it out there. Has this happened to anyone else? Please I am very worried as I have spent all my money buying this car...

 

No way to diagnose what your problem is without driving the car. It sounds like something may be loose under the car. Since it does not happen every time you brake, it is probably not a problem with the brakes. When you do brake, weight shifts forward on the car and something must be loose and banging around - motor/transmission mounts maybe? Loose exhaust pipe perhaps? It is definitely not right.

I also have a '96 3.2TL and I believe that I have replaced the motor mounts on the car.

You should use premium gas in the car. It will run on regular and the computer will adjust the engine to compensate, but you will get less acceleration and worse fuel mileage.

And I am sure I don't need to tell you that you don't spend all your available cash on any 16 year old car and not keep some extra cash for inevitable repairs....