Have I been misled by my mechanic?

Question

I drive a 1997 Jag and recently (after a long trip out of state and using the cruise control a lot), I noticed that the gas pedal was acting funny (most of the time it was fine, but every now and then, it would hesitate or not respond at all without several pumps. It usually did not occur at a light or stop sign, rather, it would happen when I would be in motion and try to accelerate my speed a little). It wasn't consistent ... and the more I drove it, the better it seemed to get. I drove it for an entire day without any trouble at all, but the following day, I got about 10 minutes from home and the check engine light came on, the car started idling VERY rough and a significant amount of blue / white smoke was coming from both exhaust pipes. I was able to drive it to my local repair shop. They replaced all of the spark plugs, the #4 ignition coil (it has 6 coils total) and did some other general minor maintenance. Upon picking up my car and paying the $700 tab, I drove exactly 2 blocks from the repair shop when the problem returned. The symptoms were the same (extremely rough idle, severely diminished power and heavy blue smoke from the exhaust), but it was much worse this time. Now, the mechanic is telling me that he needs to replace a leaky injector on #5, and it will cost around $300 more for the parts on that repair (plus labor). I have used this shop in the past and have always been pleased, but am concerned that they misdiagnosed the problem this time. He apologized that they did not catch the leaky injector issue the first time around and said that the coil replacement they had already done would have still been necessary. I am just wondering if that is true since the coil replacement didn't seem to solve the problem at all. Any advice you can offer would be greatly appreciated.

Answer 1

Ask them what their warranty policy is on their work. Either their diagnosis was wrong or incomplete.

Answer 2

well the same stuff was happening to my car but not the smoking part. i took it to my mechanic and he replaced the sparks and wires. and that didn't fix it, then he took off the catalytic converter and knock all the stuff out of it, and it started running just fine... that might be the problem just your exhaust line or something to that nature.

Answer 3

Most mechanics don't actually KNOW what's wrong with a modern automobile. They read the diagnostic codes and start replacing parts until the codes clear and send you on your way, only to have you come back fifteen minutes later with the same problem. This could go on for thousands of dollars or the injector could clear the problem. The probability that you needed an injector, coil and plugs is almost zero. These things do not combine and fail together.

Answer 4

I think Joey might be right , a plugged exhaust. I do not think one leaky injector would cause all the problems you described. I wouldn't let them touch it again unless it would be to check the exhaust. I have heard that when the converter gets plugged up that the exhaust gets cherry red hot so the next time it does it take a look.

Answer 5

It is hard to be sure about the mechanic. Maybe the coil did need to be replaced, but we will never know. Tell him that you want him to guarantee his work - that he can fix the problem that you describe, and that he isn't just replacing parts. The problem could definitely be a leaky injector, but to me it sounds like a problem with the fuel filter, or a clog in more than one injector. If an injector is actually leaking, ask him if it is leaking into the engine, or on the outside. Leaking into the engine could cause smoke, but it should be black, not blue. Tell him to check the PCV valve and replace it if it might be bad. And if he wants more than $40 to replace the PCV valve, he is trying to rip you off.

BTW, you could replace the entire engine with a Chevy 350 for $2500-$3000, and it would be considerably more powerful!

Answer 6

Ask them if they have done the throttle body cleaning around the carburetor/intake. If not that will make it run rough. Also it could be a pcv valve.  

Answer 7

No I'd say the coil was probably bad as well. He just missed the injector. If you have have used this shop in the past and been happy why start questioning them now. Auto diagnostic is not always easy sometimes problems are intermittent, if it was good when you left the shop how would they have been able to diagnose it.

Oh and Joey B, I'd keep quiet about that, both you and the installer are punishable of a Federal Offense by Section 205 (a). The operator's fine can be no more than $2,500 and the installation agency no more than $25,000.

You could buy a lot of catalytic converters for that price. :)