My 2006 Passat 3.6 VR6's CHECK ENGINE LIGHT

[johnjohn4011]

This is my first car and I've only had it for two and a half months. A storm came recently and it's been really cold. Sadly, my car is parked outside all the time and it goes through all the frigid temperatures. The other day while I was driving, my check engine light illuminated (not flashing). There was no surge or loss in power and the car still drives like normal. When I turn it on and let it idle, there is quite a lot of vibrations from the engine compartment. I have tried something that I believe could've caused the light to turn on. With this in mind, the gas cap doesn't click when I twist to lock it in. Instead, it goes for about two inches and resists. So I'm wondering if the gas cap not clicking is innovative "German Engineering" or the weather is warping it to break the seal? Also I'm wondering if I need to be worried about this CEL or if it's just temperature related. Any comments would be greatly appreciated.

-JohnJohn4011

[jddaigle]

How old are the spark plugs? Have you tried running a treatment of injector cleaner through it? Sounds like the cold weather is causing one or more misfires.

A loose gas cap can also cause a MIL, but the misfires definitely are. You may need to get a new cap if this one is worn out for some reason.

[johnjohn4011]

Sadly, because this is a used car, I do not know the condition of all the parts. I am taking it to AutoZone soon to get the fault codes read. And depending on what they are, I'll start from there. Thanks for your help and I'll let you know what was wrong.

-JohnJohn4011

[timpz]

My engine light came on when one of my 5 (Yes FIVE !!!) Oxygen sensor was dead. Might be the case of yours aswell. Only thing what you might notice when you have dead oxygen sensor is higher fuel consumption.

[swelter]

Bump. I'm curious to what you find out JohnJohn

[johnjohn4011]

So I finally got it fixed. The check engine light came on because the car was running too lean or something like that. The only consequence from that was a small decline in my MPG. Anyway, the real problem was my low battery that I was unaware of. Got a new battery and everything is fine. Runs better than when I purchased it in October.

[johnjohn4011]

I suppose I spoke too soon. My check engine light came on again today. At the same intersection it came on last time too. Weird? Anyway, I was reading through the manual and I came to the conclusion that it may be that I need to use higher octane fuel on my V6. Since I bought my car, I've used 87 and both times the engine light came on soon after. Comments?

-JohnJohn4011

[e10rice]

I dont have the V6 but my 2.0T is suppose to use at min 91 octane and i only use 93 octane. I've heard the only down side to using lower grade fuels on cars that are suppose to use higher grade is lower fuel economy and the possibility of deposits due to dirtier fuel.