What is going on with my car?

August 20, 2007 5:40 AM

Help me with my car!

I have a 2001 Nissan Altima. It has about 91,000 miles and has been very reliable. Two different times over the weekend it went nutty. I was sitting at a red light, A/C on, radio on and it died. But, the radio and A/C stayed on, only the engine died. I was able to start it up again right away with no trouble. It's also been idling weird, sort of jumpy and I thought it could maybe be an exhaust leak.
I have full intentions of taking it in to get checked out, but wanted to see if you had any idea what the problem might be and how much cash might need shelled out.
Thank you in advance!

posted by Elaisa to grab bag (9 comments total)

Had you been driving at highway speed prior to stopping? Maybe exiting a freeway? If so I'd look at your EGR valve. When cars just die at a light like that, more often than not the EGR system needs cleaning.
posted by sanka at 6:09 AM on August 20, 2007

I had something similar; it ended up being a loose distributor cap. Really annoying problem.
posted by EastCoastBias at 6:16 AM on August 20, 2007

There is really not enough information in your post to get to a specific diagnosis, so generating a cost estimate is impossible. If the engine died while idling with the A/C on, the A/C would have eventually not cooled, although the blower fan could have continued running. That's because the engine has to be running for the A/C compressor to be operating, pumping refrigerant around your A/C system, for cooling to continue. So, I think you heard the blower motor still running, and the radio kept playing; the engine just died.

You say the car has been idling "sort of jumpy." Many things could be causing that, from dirty fuel injectors, to bad spark plugs or spark plug wires, to the coil pack, to parts of the engine management and emissions control system. Your car has a diagnostic port on the Engine Control System, which can be hooked up to a diagnostic machine. Your car produces a lot of sensor data as a byproduct of normal operation, and if the Engine Control System is sensing problems, it will store error codes that a mechanic can read to determine what problems the car is reporting. Some auto parts stores will connect a diagnostic machine for free, and give you the error codes, as a means of getting your parts business. Or, you can usually pay for a diagnostic as part of a service package to fix the problem.

If your car has never had a complete tune-up, it could be high time for that. That would include oil & filter change, air filter, fuel filter, spark plugs, plug wires, PCV valve and probably belts. At 90,000 miles, you may also need to have your coolant changed, along with transmission fluid & filter. Your brakes should be inspected. A 90,000 mile service is usually around $400.
posted by paulsc at 6:22 AM on August 20, 2007

There is really not enough information here to say for sure, but it sounds like you have a problem with your ignition firing - maybe one of the cylinders has a fouled spark plug. You might have even blown a cylinder, which would be very bad.

If it's something simple like a plug or plug wires, it won't cost much. If it's something to do with the engine, like a blown head gasket, cracked piston head, etc., it will be very expensive.

If your mechanic can't find a simple answer for your problem, he'll probably perform a compression test. If one of your cylinders has low compression, it's probably going to cost you a lot of money.
posted by CRS at 6:24 AM on August 20, 2007

Using Occam's Razor, it's unlikely that a car which has had no problems suddenly blows a cylinder. It's most likely a plug or a plug wire. With the exception of a couple GM cars that have all manner of "pretty" stuff on the engine that makes changing plugs an absolute bitch (which doesn't apply to your car), and a couple random foreign cars that are REALLY proud of their wires, plugs and wires would run you a couple hundred.

Longshot, it's a fuel pump, which requires the tank be dropped - much more spendy.
posted by notsnot at 6:46 AM on August 20, 2007

In answer to Sanka's post, I was going from one stoplight to another, maybe 3 blocks in between each one. I didn't get over 25 mph each time.

Thanks for all of your answers!
posted by Elaisa at 6:51 AM on August 20, 2007

I had similar problems after replacing the alternator on my '95 Camaro, ended up being just a loose battery cable; I hadn't clamped them down tightly enough after my repair.
posted by lohmannn at 6:57 AM on August 20, 2007

Strangest one I have seen was a Nextel phone. It would cause the ECU (computer) to go crazy. Just another idea. I wouldn't have believed it myself if I didn't get to try it.
posted by Climber at 8:06 AM on August 20, 2007

my pathfinder had a problem similar to this. completely out of the blue - i was stumped - i yanked apart one of the main plugs on the engine's wiring harness and found oil inside. cleaned it out with alcohol and a q-tip and it ran fine! how the oil got in there is a mystery, but it appeared to have seeped inside the wire's insulation from somewhere in the bowels of the engine.

point: could be anything.
posted by klanawa at 8:59 AM on August 20, 2007