So we're set to leave town on a much-needed weeklong jaunt tomorrow morning and my wife's car, the one we'd planned on taking, had to slog through some water during a thunderstorm this afternoon. 10 minutes after that, she's having trouble accelerating at low RPMs, the check engine and battery light come on, and after pulling over onto a side street and slowing, the engine cuts off. She didn't immediately restart it, but waited 20 minutes, it started fine, but during the rest of the drive home, she could feel the engine struggling as she slowed down and accelerated from low speeds. 4 hours later, it's still doing this. The battery is about 3 years old, and unfortunately her car doesn't have a voltmeter on the dash, so I don't know if the battery is suddenly having trouble putting out juice or her alternator is wacky or god knows what because fuck if I know anything about car electrical systems. I checked to see if the air filter was damp and the top of it was dry. I wasn't sure if there was any point in pulling that out to check further. We can always take my van, but I hate to take the hit on mileage over her compact car. If there's some idea of what this could be and any way I could fix it before tomorrow morning that'd be peachy keen.
O2 sensor Take it to Auto Zone or Advanced Auto Parts for a free check engine light diagnostic test. Low voltage or failing alternators do not lessen power. "Powerful" batteries are a marketing gimmick, either your engine fires the cylinder or it doesn't, and if it doesn't then your car is going to just turn off or not start at all. A bad alternator (but a good battery) will show itself as dying electrical systems (your radio turning off, your lights dimming noticeably)... it's a separate problem than a battery.
Oh, I forgot to mention that when the engine started up again, the check engine and battery lights were both clear. No more dash error lights.
If the engine is struggling at low RPM, a check engine light will most likely return. The struggling can also be a result of water in the gas tank, but I'm not sure at all how that could happen just by driving through water. Do you know how to pull spark plugs?
Know how, in theory. I trust myself to do that about as much as I trust myself to perform a self-treppanation.
I'm planning on taking it for gas in about an hour. I got a bunch of trip prep I can't put off. Freeway or surface streets?
Surface streets, keep it in the problem zone (where it's struggling) for as long as possible to try to get that light to come on.
Good news - During my trip for gas an hour ago, absolutely no problems at any speed. Practically travelled a mile with my foot off the gas idling along, then drove like an asshole speeding up and slowing down really quickly on the return trip. So what gets wet, causes weird behavior like described, and then goes away once dry? O2 sensor still a candidate or do I have to be happy with "Gremlins" as a diagnosis?
Good to hear. It's hard to know. The water could have been a coincidence, or some electrical connection could have gotten wet somewhere that set off the computer with a short, in which case an engine can run in a "legacy" mode where the fuel injection isn't fully featured or running without full data (hence my asking about O2 sensor, in other cases it's Throttle Position Sensor or Knock Sensor). I'm not certain how the car would react if the muffler were submerged for any period of time, though I'm thinking that would be a very clear case of water traveling to and fouling the O2 sensor enough to get the ECU (computer-controlled fuel injection) to go into that "safe mode." There are some basic electrical connections you can check and maintain to protect the system against wet conditions. Dielectric (or silicone) grease can be rubbed into the rubber "boots" that you pull off of your spark plugs in order to seal them against water (while also preventing corrosion), and likewise for your battery terminal (you can clean those with a toothbrush, one at a time, while not touching any metal part of the car, making sure not to get any of the white powder on your skin or eyes (and fully clearing that stuff off of your battery, even if just with a moist paper towel wiping around the terminals). You can usually loosen the metal brackets that connect the cables to the battery with a screwdriver or pliers (again taking care not to ground yourself against something when you're working with the red/positive terminal). If the light comes back while you're driving, use a smartphone to find the nearest Advance Auto or Auto Zone, shouldn't be hard if you're traveling by highway. You should also not panic, because if this crops up again I'm 100% certain it's an O2 sensor and you won't cause damage to your car. The only things that really cause damage to a car are sounds of metal clanging or grinding, low oil or low oil pressure (oil light comes on), or a blown head gasket (temperature shoots up noticeably).
MOAR CAR PROBLEMS My wife has had flat tires more than is statistically plausible. Since buying her tires from Discount Tire in 2006, she has at least one replaced per year. Often the same tire, but sometimes different ones. I'm pretty sure that at this point, none of the tires are the original ones from 2006. I should note that all but one of the flats was not due to puncture or road conditions. Thankfully, we bought a warranty on the tires, but it's still $10-15 a pop to buy the new warranty for the replacement tire. After the last one got replaced (June-ish?), she asked why this was happening, and the guy speculated that all the rust in her wheels are causing abrasions on the inside of the tire that eventually wear through. Does this sound plausible or are we just being given shitty tire after shitty tire?
I think the claim about "rust in the wheels" is hogwash unless there's visible abrasions around the inner rim of the tire. You could put broken glass inside a tire and it won't do anything because there's not enough friction against the rubber. When you get new tires installed, do you get the alignment adjusted (not just checked)? If the alignment's off, that magnifies uneven wear on tires over time.
I'm sure they did the alignment back when the tires were replaced as a whole, but it's unlikely there's been any adjustment to alignment since then. Um...so...if I broke one of the bolts coming out of the hub while trying to get the lugnuts off, how fucked am I?
Is there actually rust in the wheels? If there is rust where the bead of the tire sets, then yeah a tire could eventually run flat, but to happen to all of the wheels is definitely statistically implausible. On my old car I ask them to clean the rim. Some places will do it automatically but most won't until you ask them, because the dude changing the tire has shit to do and doesn't really care if you go flat in a month. Buy a small pressure gauge and keep tabs on all the tires. One time I was getting a flat that I couldn't figure out and it turns out the valve stem was ripped, so when checking air pressure push on the valve stem a bit in all directions to make sure you don't hear any air coming out. Holy shit how old is this car? Is it the same one as before?
You can search "broken wheel stud" to do the fix yourself if you want. Otherwise you can drive it to have it fixed, don't let them screw you on price because you can ask to have it done with just a fresh threaded bolt and a lug nut to hold the bolt in place. Driving on 3 out of 4 studs will be alright to get it there.
If you're having your tires replaced at Discount Tire they DO NOT do alignments. Get an alignment done as soon as possible and have it done every other time you have your tires rotated. If you're still having tire issues with a proper alignment the next thing I would check would be the rims. With so many new cars moving to low profile tires there's more stress on the rims and if they have a developed a defect they can cause tire issues.
$20-$50. If they start talking to you about replacing the whole rotor//hub, ask if they know anywhere else that will just replace the stud, because it's not necessary to replace the whole thing.
No argument there. It's a catch22 though - As long as they're putting new tires on the car, it doesn't make sense to buy news ones elsewhere.
$10 for the part, $30 for labor, done in 40 minutes. Not gonna complain about that. Thanks man, the first place I called pulled the, "Well, we might have to replace the hub, so it could be anywhere from $50 to $100." PLONK.
