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Check engine light flashing......again!

Now I know I’m having problems when I go to start my car, and the check engine light starts flashing and my engine is idling really erratic. What could this be? I have a 2000 Buick Park Ave. I went to start it today and voila… problems. I have had this problem before and it seemed to correct itself.

I started my car. It was kinda rough when I started it. My engine started trembling and check engine light started flashing. I turned my car off and back on and it went away. No check engine light…no trembling…nothin!! Well, at least til now. I went to start it up and the same thing happened…really rough idle and my check engine light started flashing.

I was recently told it could be a misfire, but I was also told by a family mechanic that it could just be a faulty plug or shorted wires. Any help would be greatly appreciated. Also, recently when I have been driving, my car has been feeling a little sluggish right around the 2nd gear mark, and I have watched my voltage gauge on my dash jump around a lot, anywhere from 11v to 13v. Could this be a symptom? Or the effect of something else? Please again…any help would be greatly appreciated. Oh, and before I forget, how much can a problem be fixed for? I don’t want to get ripped of for something as simple as changing some spark plugs or wires. Thanks in advance!!!

Get the battery and alternator tested.
Check for loose battery or ground strap connections.

thanks!!! i will have it checked out…any other suggestions? i have a mechanic coming over in the morning, and i would like to be able to throw some questions around with him and see how much he knows before i have him working on my car.

You need to have someone pull the error codes from the computer - the engine light is telling you that they’re in there. When you get them, write down the exact codes, such as “P1234” Many auto parts stores will read these for free.

A flashing light usually indicates a pretty severe misfire (codes for that will be something between P0300 and P0306). Don’t drive the car when the light is flashing.

One possible cause of a misfire is a plug/wire problem. How old are they?

Having the battery/alternator tested at this point is also a good idea.

A flashing check engine light means you have a misfire – one or more cylinders is not firing – which explains the rough idle. You should not drive it if possible, or only drive it to a shop, slowly and carefully. A misfire means that unburned gas from that cylinder is going straight to the catalytic converter where it can cause damage if it goes on too long.

Exactly why it is misfiring is currently a mystery. It could be a bad ground, bad spark plug wires or bad spark plugs, bad coil or bad ignition control module. Your engine computer will have a code indicating which cylinder(s) is/are the problem, that will help to narrow it down.

All three problems could be related or they could be three separate problems. It’s hard to be more specific without a proper diagnosis.

The actual list of possible issues is even longer than StrongDreams provides. Other than the systems that deliver “spark” you have to also worry about fuel (e.g. pump, pressure regulator, injectors), air (intake/vacuum system leaks), and compression (valves, timing, pistons, etc).

A good mechanic can check all that kind of stuff out.

Many people do start w/ plugs & wires b/c they’re cheap & good maintenance no matter what.

A “flashing” check engine light is to highlight a serious problem, likely not a simple misfire. Your mechanic needs to have a code reader at a minimum.

Great!!! Thanks for all input!!! It sounds like it isn’t like a head gasket or anything which is gonna save me a lot of money from what I’m told. As long as it’s not an internal engine or some other problem like that, I should be okay. I will try to get it to autozone to get the error codes as soon as possible and try to figure this out. With all the possibilities, can anyone give me an estimate of how much I should pay for something like this to be fixed? I know it depends more on the specific problem I’m having, but a ball park area would help me out a lot. Thanks

Check engine light is no longer flashing…but is on…but still having rough or erratic idling and it gets worse when I throw it into gear to drive.

A lit check engine light means something is wrong.
A flashing check engine light means something is VERY wrong and it should be fixed as soon as possible.
(An oil light or coolant temp light means pull over NOW or kiss your engine goodbye.)

A fuel or spark problem could be intermittent. You have the same issue as before, just slightly less bad at the moment. (By any chance was it raining when you last tried it and dry now.)

(And, sad to say it could be a head gasket, if leaking coolant has fouled one of the cylinders. It’s unlikely, unless you have been having overheating problems that you did not disclose in your first post.)

Best to leave it for the mechanic if one is coming over.

It sounds like it isnt like a head gasket or anything which is gonna save me alot of money from what im told. as long as its not an internal engine or some other problem like that

Don’t get too excited, although I don’t want to make you panic either, but bad head gaskets and internal engine problems DO create serious misfires. That’s among the things I was trying to say above.

A misfire means that combustion didn’t take place properly in one or more cylinders. For combustion to happen you need 1) fuel; 2) air; 3) compression; 4) spark. Head gaskets and other engine problems fall under compression problems.

The first thing is to pull the codes. If all you have is misfire codes then the next thing is to check out the plugs and wires. While the plugs are out the compression should be checked to rule out a mechanical engine problem.

Yes strongdreams…both times it has done this, it was raining. Well, it is raining…and as far as the head gasket thing…I did check for coolant in my oil and nothing. Recently, I have had some overheating problems, but it has been fixed for a while now. I had a slight crack around the intake of my radiator and fixed it with a radiator repair epoxy I got from autozone and haven’t had a problem since. Other than that, nothing major with overheating…no oil lights or coolant temp lights…nothing other than this!!! What’s up with the rain thing??

Y’all are a major help!!! When the mechanic comes, I will also have him check the compression when the plugs are out, but I am definitely gonna get the codes read asap. There’s an autozone like 1.5 miles from my house. I know I probably shouldn’t, but if I drive it there, can I make it worse?

If it happens only (or mostly) when raining or very humid, that points to spark plug wires as the first likely suspect. Over time, the insulation develops tiny cracks and becomes less effective, water helps the electric current jump out of the wire, so there is less electricity (or none) going to the spark plug. Also, the boots of the wires (where they connect to the plugs and seal out water) may be cracked.

Sometimes, if you open the hood at night when it is dark, you can actually see the sparks dancing around as they arc from the wires to the engine block.

Also, you may be able to duplicate the problem, or make it worse, by spraying water on the wires (use a plant mister, not the garden hose!).

And finally, if you drive long enough to get the engine compartment hot, the problem may go away because the heat drives the water out. But this may not be a safe thing to try if you are getting misfires, you could wreck the catalytic converter.

I’d definitely say that new wires are the first order of business. Plugs too, since they are cheap, if your current plugs are over 2 years old. The condition of the internal side of the spark plug will give your mechanic clues to other possible problems if present.

Ask your mechanic friend to bring a set when he comes over. (If that turns out not to be the problem, you or he can hopefully return them.)

I don’t know how much unburned gas you can dump in a catalytic converter before you ruin it, but why take the chance?

If you pull the plugs, save them, and mark which cylinders they came from, so whatever mechanic this goes to (if it does), can see them. They can provide clues, as SDWH said.

And if you change the wires yourself, take some pictures first and mark which wires go to which cylinders. You don’t want to mix up the wires.

StrongDreams and cigroller, I am definitely gonna take you guys advice and start with the plugs and wires and have them replaced first!!! Plugs are definitely older than 2 yrs!!! And thanks, I will not drive it at all until I get this taken care of. I don’t want to lose my catalytic converter or my engine for a short trip to autozone!!! Also, I did try to look for some dancing lights before at night around my plugs and wires, but never saw anything. I didn’t know I could mist some water to get it to react. I will try that again tonight. I will get back to you guys tomorrow after the mechanic stops by. Once again, thanks for everyone’s input. It definitely helps…LETS ALL HOPE FOR FAULTY WIRES!!!

“i have watched my voltage gauge on my dash jump around a lot anywhere from 11v to 13v”

Plugs, wires, fueling, etc. won’t cause this.
But system voltage instability could cause the misfiring.
So I still think the root problem is electrical in nature.

Went down to start it this morning and it turned over fine…engine still rough and shakey…Also after a sec. I started to hear a knocking/ pinging from under the car…Could this also be a symptom of a misfire or a catalytic converter problem? And @ strong dreams…no, he’s not a buddy with tools. He is a mechanic, but recently his personal garage was broken into and someone took all of his tools among other things. Oh, and when I put the engine in reverse, it seems to get a little better, less shaking, but when I put it into drive, it gets worse than when idle. All clues or am I just paranoid…never heard it before today.