One more car question

Factual Questions
1

I hate to admit it but I have a '95 Chevy Corsica with 108000 mi. I haven’t bought a new car because until now I’ve NEVER had any problem with this one.

I’m driving home from work and it’s eleventy million degrees out, and like every day, traffic sucked. All of a sudden my car just did “feel” right (anyone who’s put those kind of miles on a car knows what I’m talking about). So I get off the next exit and I find that I’m going 0-60 in about 3 1/2 days. It’ll move, just…very…slowly. So I take it to the dealership (it was close and I didn’t think it safe to drive).

So it seemed to me that I has lost two of my four cylinders. Thus, I’m thinking spark plugs, distributor cap…etc. Then I’m thinking maybe my catalytic converter got fouled.

Well, the dealership said it was the coil. “HUH?!?!” I said “that doesn’t seem right to me at all”. Then the dealership said “gimme $600.00” to which I said “gimme the damn part”.

So now I am out $600.00 bucks.

My questions are…Does this sound right? How can I get this part checked to see if it was really bad?

Oh BTW My exhaust sounds funny now

2

I’m not a mechanic but I DID play one in a radio commercial last week and besides…you are asking if what happened ‘sounds right’, not for specific mechanical advice.

Coils don’t cost $600. If I were the dealer, I’d have your picture mounted in a gold frame and hung in the service manager’s office if you paid that much for a coil.

A coil is basically a step-up transformer and they do go bad, but the usual result is that the car won’t run at all. But it MIGHT cause the problem you describe. Unfortunately, almost all engines manufactured within the past couple of decades are so complicated that no one…including the dealership can figure out what’s wrong with one even with the help of diagnostic computers. But ther are a couple of exceptions. Buy a 2001 VW turbo diesel engine in either a Jetta or a New Beetle. Diesel engines have no electrical components except starters and glow plugs. So if the coil goes bad it doesn’t matter because there isn’t a coil.

If whatever they replaced fixed the problem though, everything sounds fine with the exception of the cost and, of course, your exhaust.

Disclaimer: This is my totally uninformed opinion backed up by nothing. Don’t bet the farm on it. I just need the typing practice.

3

Is it not possible to pick up such a thing at a wreck dealer for a fraction of the price?

4

You could have just visited their parts dept & asked. But thats too much for a coil. It was probably around $50 the rest labor.

5

I’ve had success with “engine diagnostic” type places. They hook your car’s computer(s) to theirs and it can tell the mechanic exactly what’s wrong most of the time.

6

Well I had already figured I’d gotten screwed on the price, but there’s not a whole lot you can do when that is the only place I could take it. The thing is, I suspect that they didn’t even make the correct repair.

What I suspect they did was either replace some spark plugs and/or punch a bunch of holes in my catalytic converter.

But back to the original question. Will a bad coil foul spark plug (or cylinders) and how can I get this part checked to see if it was really bad?

7

A bad coil will simply not produce sufficient voltage to cause your spark plugs to fire across the air gap. ANY spark across the plug at the right time will result in ignition if the mixture is right. Fouled plugs are usually a result of an incorrect fuel-air mixture in the cylinder. Take your car to someone who can look under it and see if the catalytic converter or muffler have been buggered. If so, put the old coil back on and see if the car runs. If it does, you have a pretty good cause of action (legal and civil) against the dealer. But I really can’t imagine a car dealership pulling a stunt like that. They could lose their dealership.

8

Well, I am an engineer and I was a mechanic, so I’ll hazard a guess:

Perhaps yours is one of those cars where the coil, ignition module, and other parts are all in one piece? A friend with a 1990-something Dodge Colt supposedly had to pay $400 or so for a new coil/ignition module, and like in your case it didn’t fix the problem - it was a simple throttle position sensor.

A weak spark can in theory foul your plugs, but that’s not usually how coils die anyways. They always seem to be 100% or 0% devices - they either are working, or not. Bad wires can reduce voltage, but come on - you don’t see that suddenly happening in the middle of a drive.

I don’t think the coil/ignition module was the issue, based on your description. However, it would be impossible to guess what your real problem was from the description and without examining it. And with a car like that it’s a good idea to check the cat and exhaust, it seems like what I’m hearing is a sudden failure of an engine-management related part, such as the ignition module or a sensor. This could explain the exhaust sounding funny as well.

The short of it - you need to save the old part, go back to the dealer and demand a refund on the new part unless they can prove that the old part is, in fact, actually broken.

9

I will give my 2 cents worth. I work in a Chevrolet dealership. (no not a mechanic). However I do work in the Service Department. The Chev. Corsica, especially with the 4 cyl engine, does not have a distributor. Each 2 cylinders are controlled by a coil pack. So, if they told you that 2 cylinders were dead, they were probably telling you the truth about the coil. The engine will run on 2 cylinders, but not very good, as you described, 0-60 in a year or so.

As far as the converter plugging up, that is possible, considering that you have 108,000 miles on it, but it would NOT happen in the apparent few miles you drove. Besides, you would have noticed symptoms, such as no power on hills, long before it got to the point of being plugged.

Did the coil fix the problem? Does it run good now, just makes noise? If the exhaust is noisy now, it may be that the coil going bad caused the engine to run too rich, which in turn caused the converter to plug up, but as I stated earlier, they don’t plug up in just a few miles.

As for the price of the coil, did that $600.00 include all the diagnosis time, parts and labor to install it? If so, depending on the labor rate in your area, that is probably close to correct. The ignition coil packs, as they are called, are pretty expensive, as they do everything that a distributor does in other cars.

On another note, have you had the fuel filter changed recently? That can also cause running problems, but not usually the kind you have described, unless is happens to be so plugged that it takes out the fuel pump, which is electric and inside the gas tank. (doesn’t make sense to me either).

Hope this all helps you.

P.S. Be glad you don’t own a 1999 Geo Metro. A MUFFLER for one of those cars is over $800.00, just for the part!! Makes me wonder if they are made of gold or something.

10

One thing I forgot to mention. Most G.M. dealerships, as well as independent shops, have a policy that they will not take back an electrical part, whether used or not, and especially if it has been installed on a car.

11

Today at work, I checked on the price of a coil pack. The price was $55.00. Way more than I thought. So, unless you had a bunch of other work done also, you got ripped!!! If this is the case, go back to that place and talk to the service manager. If that doesn’t work, talk to the owner or general manager. There is no excuse for being charged like that. If I charged a customer like that, I wouldn’t be able to sleep at night. If you don’t get any satisfaction at the dealership level, call Chevrolet Customer Assistance at 1-800-222-1020 and tell them your story. Good luck.