2003 Pontiac supposedly has water in gas tank - nefarious mechanic shenanigans?

2003 Pontiac Sunfire, 103K miles, a little overdue for an oil change, but no major (or minor) problems before now:

Last Monday my car was running fine until, on my way out of town, I gassed up. Immediately, my car started acting strange: immediately died upon leaving the station, didn’t want to start, RPMs all over the place, acceleration & braking weren’t responding properly, TERRIBLE idling, difficult handling at higher speeds (>45 mph), check engine light eventually came on, as well as the battery light (for just a minute).

Needless to say, I decided not to go out of town and took the car to a local mechanic (by this time the car was dying regularly and absolutely did not want to start). This morning he told me that I have water in my fuel tank and detailed a draining process that sounds expensive. However, after reading several “water in gas tank” threads on here, I’m skeptical. As a young woman living the in the South, I’m sure you all can understand my suspicion. So, is he giving me the run around? For what it’s worth, I do live in southern Louisiana - hot, humid, rains daily - water isn’t exactly scarce here.

Someone (Father) mentioned my timing belt (I haven’t had my 100K-mile service yet, so belts and things are probably due for a replacement). Another non-mechanic thinks it’s my transmission. Thoughts?

Your words.
Sure sounds like classic ‘water in the fuel’ from the gas station scenario.

It may already be too late to prove it to the station so they could pay for the clean out, but you could try.
Any other cars with problems leaving the same station on the same day ? ( ask ALL the nearby repair places if they’ve had other cutomers. )
If you pumped some gas today from the same place into a clear container, would it have water in it ?

These sort of proof questions should have been determined right away in order to prove it’s the station’s fault.

But yes, it sure sounds like a water problem.

Careful with that timing belt now too. That rough running engine can cause some new stress to the old belt that it may not like. What does your owner’s manual say is the timing belt replacement interval ?

It is possible to get “bad gas” though its true that this if often something people say when they are clueless and don’t really want to deal with an issue. Describe this gas station - age? condition? how busy is it? major name brand or generic?

As for the other possibilities, what you have given is way too vague & full of different kinds of stuff. So, e.g. “terrible idling” and difficult handling over 45 are two entirely different things.

So try to clarify with more descriptive terms of what the car was actually doing. You also need to find out what error codes the mechanic pulled from the computer and report them. They look like “P1234”

I’m fairly certain that your car uses a timing chain rather than a belt. Unless you’ve completely abused the engine & haven’t maintained it then its very unlikely that you have an issue with it at only 103K.

It’s possible to get contaminated gasoline but in most cases that theory is a fall back for someone who does not know, has no clue, and is either making a stab in the dark or is just trying to cash in on a quick process to be rid of the car, while padding the pocket of course.

Any mechanic who gives a water in the gas diagnosis should be able to provide a sample fresh from the tank (1 quart at a minimum) to back up his claim. If he can’t do this then he’s making a wild guess at best.

I’m in agreement about your complaint being a bit vague and getting the codes pulled.
The only thing I can theorize about the terrible handling part of this is that the engine is running so poorly that you’re equating any bucking and jerking felt in the steering wheel to a handling problem.