Home Forums Hunting & Shooting Hunter's Campfire Check engine light

came on in my 2005 GMC pickup. Great, I thought, another $200 gone. I wish. It was two sensors called 'knock' sensors that notes when the engine starts to do something that used to make the valves rattle and it retards the timing. I could have put a piece of black tape over the light because my mechanic said that it wouldn't hurt to drive it. Problem is, though, if something else goes wrong the light won't warn me.

With a long breath (a sigh to you city folks) I axed him how much would it cost. They are located, of all places, under the intake manifold so everything has to come off. The book gives 3 hours and that's what I was charged for but it really only took 2 hours. Total= $600.54 for everything. That took care of my gun show this weekend but, Lord knows, I have enough guns.

Best part of all? My check engine light is off. You know you're living right when the check engine light not burning is one of the highlights of the day.

The one in my Taco has been on for 7 years.....

I don't get worked up over 'check engine lights'. Much of the time it's an 02 sensor in the exhaust system or some minor issue. You need oil quantity and pressure, and the cooling system in tact. Yes I've heard about the better fuel mileage and other issues, just seldom see any higher priority reasons for the light.

It's almost a boderline scam to get you in the shop too.

Only about 4 years for me in my Tojo Camry. $400.00 to turn off the light in a $1500.00 car seems a bit much to me.

" It's almost a boderline scam to get you in the shop too." Yup, sure is.

I panic when it goes out.

That knock sensor system will prevent your engine from pinging (pre-detonation). It is a helpful measure to prevent damage internally (pistons). Think of the $$ you spent as insurance for the future life of the engine.

BTW.. the check engine lite illuminates for a number of reasons, possibly 200+ different permutations. Everyone assumes HO2 sensors because of what they read in magazines or see on the boob tube. This can not be further from the truth.

Also many states will deem a check engine lite a failure for the inspection process.

-Ken

What's this inspection process you speak of

The check engine light would come on on a Ford Escort I used to own whenever the gas filler cap had not sealed well. I would imagine a loose or worn gas cap could do the same on some other brands of motor vehicles.

Not "borderline" at all. It is a royal scam. And the car manufacturerers keep making it more and more expensive and difficult for noon dealer machanics - let alone do it yourselfers- to diagnose or repair anything. And yes, they do it ON PURPOSE. One of the big reasons that mechanic shops have to charge such a high hourly rate is to try and amortize the cost of new diagnostic equipment constantly. Plus the high cost of liability insurance due to all of the ambualance chasers and folks who try to turn an honest mistake into a lottery win.

I am going to sell my '03 gas rig, (check engine light has beeen on for a couple of years now) and get a pre 2000 Diesel 4WD truck of some kind. Most likely something with a 7.3 Powerstroke or a Cummins 6 cyl turbodiesel.

Many states have annual or bi-annual vehicle inspection programs for safety as well as emissions systems. Without the inspection you are unable to re-register the vehicle.

-Ken

This is why I'm a fan of pre smog vehicles

I know its not much consolation Mickey, but a Porsche 993 requires engine removal to be able to remove the intake manifold, then the tin cooling ducts, to get to the knock sensors which are only $245.00 each. Soooo, mid teens in labor plus parts. Oh, and while you're there, might as well replace ignition wires as they also require manifold removal to do, all 12 of them (2 plugs per cylinder) and both caps and rotors too. Wire set is about $900.00 or so.........

Chuck the Engine light is a cash cow for service departments. As for the book saying that a job that took two hours is a three-hour job and the charge is made accordingly, that is crap.

If you can afford the toy you can afford the tender.

Most auto parts stores will loan you the code reader for free, find out whats wrong buy the part and replace it.

Get an obd-II scanner so you can read the codes on your vehicle(s)

Whenever our vehicles have thrown codes I end up hooking up the scanner, saying oh crap this is gonna cost me and I've yet to get away with a bill in only the 100's.

The CEL and the self diagnostic computer systems on newer vehicles are there for a reason and they're not a scam. O2 sensors, knock sensors, and crankshaft position sensors (just to name a few) are critical for optimum engine performance and efficiency. Computerized engine management systems rely on the readings to adjust fuel mixtures and timing. Sensors in the braking system are there for safety reasons.

There are some sensors that are strictly emissions related that won't affect driveability like a EVAP sensor that detects a loss of fuel vapor which could be nothing more than a loose gas cap.

At one time in Alaska (don't know if it's still the same) all that was needed to pass an emissions test was no CEL. It was enough to ensure that a vehicle was operating efficiently and with no excessive emissions.

If your CEL is on and you want to know what's happening take it to a parts store and have them read the code with a scanner. Most all major parts chains will do it for free.

yea, worst can scenario, you can not only read the codes but clear them out too - to turn off the light until the code trips again.

Clean your MAF (mass airflow sensor). If that doesn't work, probably your upstream O2 sensor.

How did we ever get along without the check engine light? If we could pluck the bulb, we'd be back to where we were before the light and all would be good.