Car jerking slightly and check engine light flashing until temp. hits normal!

Hi there,



I’m currently driving a 97 Corolla with around 136,000 mi on it. I got it from my dad just recently, and don’t have experience fixing vehicles, so apologize for the simple/elementary description below. I’m really worried that the following issue means my transmission is going:



This only happened this morning, and about a month ago on a really hot day. I live in MN so today was chillier at around 50 when I started my car.



I started it, and right away even just sitting there it began to jerk a little. They’re very gentle jerks but enough to feel like something is wrong. I drove it out of my parking lot and sped up to about 30-40mpg to get onto a ramp. Now my check engine light is always on due to emissions and the age of the car, but as I sped up it started flashing. It’s orange and didn’t change to red, just flashed for about 30 seconds. The jerkiness still continued as I stopped momentarily at the stoplight, then when I sped up again the light began flashing again for another 30 seconds or so. My car heated up from Cold to normal pretty quick, and everything stopped after that, car began operating as normal.



Does anyone have any ideas to what this could be? It happened one other time, and my assumption then was that since I had my A/C on right away, it stressed out the engine as I sped up to merge with traffic. This time I was speeding up at a very gentle pace and no A/C. As a side note, my car also makes a louder than normal noise when driving, which almost sounds like a whistle. This is most of the time, rather than just with the situation above. Not sure if they are related.



Just thought I’d get some other opinions! A new car isn’t exactly in my budget right now, so just want to see what I can do to fix things before they get worse.



Thanks so much!

Yelena

The check engine light should not always be on, regardless of the car’s age. The CEL is a warning that something is wrong, and ignoring the warning is sure to make things worse.

Many auto parts stores will read the trouble codes in the computer for free. The codes are stored when the light comes on.

A flashing CEL means something is REALLY wrong and you should stop driving.

Check ALL fluid levels, including the transmission fluid, ASAP. That’s the first thing to do. Then have the codes read to see where the problem is. Then take the car to a mechanic and have him/her fix whatever is wrong.

If you’re lucky, there is nothing seriously wrong with your car, and it wont’ take much to get it back in tip-top shape. Has the maintenance schedule been followed for this car?

We definitely had the light looked at when it first started happening (there’s actually 2 cars in the fam and one is a 96 Corolla, the other is a 97, very similar mileage), and the code keeps coming up as the same - emissions. My dad had the oxygen sensor replaced in both I believe, and the light kept coming back on after we manually turned it off. So it has been that way for a long time. Not saying it is right, but any mechanic we spoke with made it seem like it was not a big deal.

Thanks for your insight on the CEL, this just happened this morning so I’m brainstorming what to do first.

You probably have a cylinder misfire causing the check engine light to blink. The light on constantly probably is because the catalytic converter is no longer working efficiently. So I suspect you need a tune up, and a new catalytic converter.

Thank you for the reply. Is this something that needs attention immediately? (As in between today and tomorrow), or can I wait a week or two to bring it in when I can get time off work?

I’m probably wrong about this but I always thought that a flashing cel did indicate a cylinder misfire - a persistent one, not an occasional one - that the light will flash while the engine misfires, and if it stops the light stays lit but stops flashing. In any case - the flashing is really not good and you shouldn’t keep driving until you get it figured out.

Of course, a cylinder misfire code should have come up, but a misfire will also produce emissions codes. The first thing I would do is check the spark plugs and wires. This is not hard to do even if you don’t know much about cars. They’re also cheap to replace. Just do an internet search on it and you’ll find it pretty easy get info on what to do and how to “read” your spark plugs when you pull them out.

If you want something more specific go get the codes read and post them up here. Don’t post a description of the code or what someone told you about the code - get the actual number (it will be a letter usually followed by 4 numbers, e.g. P0400).

Thank you, I will go get the code checked again at Checkers and see if they’ll give it to me free, then post.