I have a 1993 Nissan Sentra SE with an automatic transmission and a 4 cylinder engine (it's a GA16DE if that helps you.I know very little about car innards). It has about 230,000 miles on it.
For the most part, it's served me VERY well and even now still runs decently. However a couple of issues have come up that have me very worried, because I'm struggling to make ends meet *without* expensive repairs!
The main issue is that the car has started shuddering (as in, I can feel the whole car shaking/vibrating) when I am driving it. It's only while giving it gas, and subsides when braking. And it's not specifically on acceleration, because it happens sometimes when I'm maintaining speed and because letting up on acceleration doesn't necessarily make it stop. It happens erratically-- some trips it barely or doesn't do it at all, some trips it's practically the whole time, and it's happened both at relatively low speeds (around 30-35mph) and higher ones (60-65mph). It doesn't really make a noise, although now and then it seems like I " feel" a noise from somewhere up front, a slight knocking or clicking, but not consistently or often.
The other issue is that every once in a while, when I've come to a stop, the engine will stall out. It goes so completely that I can't even make the hazard lights work, and at first when I turn the key nothing at all happens. But on the second or third try, it starts up again like nothing happened. I haven't documented a specific connection between the shudder and the stall, so I don't even know if they're related.
I will say that she's definitely due for a tuneup. Her oil level right now is good, though I feel like I've had to top it off more often than usual. Her alignment should be ok because that was all taken care of recently when I had a flat tire fixed (the shudder occurred both before and after that). My biggest problem with her has been the alternator-- it was replaced right before I got her 4 1/2 years ago and has been replaced twice since, the last time so close to the previous time it was still covered under warranty.
Can anyone give me an idea what the problem(s) most likely is/are, if there's anything I can do on a basic maintenance level to help alleviate it, and in general how expensive these repairs might be? If nothing else I'd like to brace myself for what to expect from the shop.