Altima Acting Funny After Stop-and-Go Traffic

It’s hard to explain this, especially in written word. I have owned this 2000 Nissan Altima since the end of September. It’s got 162.5k miles on it, and all the shakes and rattles that come with a high-mileage car (It was the best i found in my very limited price range).

I live in (or outside of, if you prefer) Phoenix, AZ, and have put over 3,000 miles on it since i got it, because of my commute. In the winter months, the freeways are clogged up with the extra people who flock to Phoenix for the warm weather, so it’s really horrible stop-and-go.

After two days and approximately 75 miles of stop-and-go, my car does not feel the same. The engine feels and sounds rougher. There are additional problems that for reasons i won’t get into, i haven’t been able to get checked out - something is leaking, and the acceleration is sometimes kind of off.

At the moment i don’t have the money to take it to a mechanic, so i’m hoping someone here might be able to give me an idea of what’s wrong, first.

The lack of acceleration, and the rough engine, could be from lack of engine tune. Change the spark plugs, air filter, and fuel filter.
You need to determine what the liquid is that is leaking. The loss of that fluid could wreck the engine, or transmission, or steering.

Shakes are a sign of an issue that can be fixed not an older car.

You need to clearly describe all symptoms including leaks. We cannot magically through your computer diagnose. You may want to find a trusty mechanic and find out the real story on the car without biasing their diagnosis with your own diagnosis first. It may be very simple to address.

Is there a bright yellow check engine light on? If yes take the car to an autopart store and get a printout of all codes and post back.

The OP has not told us the maintenance history of this car.
Likely, he/she does not know the maintenance history, since it was purchased as a used car.
In a situation like that, it is vital to be sure that all of the maintenance listed in the Nissan Maintenance Schedule is done. If you don’t know that something vital has been done, unfortunately you have to assume that it has not been done.

Additionally, I find the last sentence to be confusing, or at least somewhat contradictory.
If the OP does not have the funds for a mechanic, what good is it to know what the problem may be?
And, I use the word “may” simply because our cyber-diagnosis of the car’s problems is not likely to be accurate.

Mechanical and electrical/electronic problems are not usually known for resolving themselves. Postponing diagnosis and repair will only add to the repair costs. This applies especially to the leak of the unknown fluid, and could also apply to whatever is causing the acceleration problems.

I suggest that the OP attempt to borrow a few hundred $$ from friends and family, and then begin by bringing this car’s maintenance up to date. Once all maintenance is brought up to date, the problems might be resolved.

If up-to-date maintenance does not resolve the problems, then at least it will be possible to do a much more accurate diagnosis. Before maintenance is brought up to date, most possible solutions will involve “cherry-picking” and random replacement of parts, and that is the most expensive way to resolve a car’s problems.