Burst of smoke; check engine light

So, i’ve got an '06 VW Rabbit. I only use it to commute to work, mostly in the colder months, which means 6 miles each way. It’s only got about 20k on it. I brought it in for the 20k service last week, and took it on a 450-mile weekend trip. no problems at all.

A couple days have passed since we got back. This morning on the way to work I was at a light when I looked in my rear view mirror and saw exhaust smoke. A lot of it. At first I didn’t think it was me, and it cleared up completely by the time I got to the next light, about 1/4 mile away. Then a few minutes later, the check engine light comes on.

I’m going to call the dealer in a few minutes and arrange to take it over there for them to look at. In the almost 3 years I’ve had the car, this is the first trouble I’ve had, and it comes right after they’re mucking about inside my engine (20k includes piston check, among other things). What are the chances the check engine light and the recent service are related? any idea what I might be in for? Think the smoke is related, or could that have been someone else?


Have you opened the hood and checked anything, such as the oil level?

You don’t know if the smoke was from your car, so we can’t say whether or not it’s related to the CEL.

There are dozens of possible reasons for the CEL to come on. Until someone reads the codes we have no idea why it’s on.

Please check the oil before you drive this car another inch.

Piston check? What the heck is that?

“piston check”???

If they actually told you that they “check the pistons”, I think that what they say at that dealership has to be taken with a very large grain of salt.

But, to get to the problem at hand, the problem is very likely coincidental.

Since you tell us that the car is used essentially for short trips in the winter months, I hope that you use the Severe Service maintenance schedule for this car since this type of driving is the perfect description of severe service. If I was driving that car, I would change the oil every 3 months–regardless of odometer mileage–and I would be very careful to use only synthetic motor oil that meets the VW specification.

If you have not changed the oil as I described above, it is very possible that the engine has a severe sludge problem at this point, and that the sludge has led to lubrication problems. Lubrication problems can quickly lead to bearing damage, and this can result in oil burning, even at the low odometer mileage that this car has.

By my way of thinking, this car should have had its oil changed at least 10 times already. If you have not changed the oil at least 10 times, and/or have not used VW-approved oil, then that is the likely source of the problem.

Beats me. Neither the receipt nor the maintenance schedule in the manual mentions anything about a piston check - that’s what he told me when I dropped it off. Part of the 20k service is an oil change - I’ll check the oil this morning to be sure it’s ok, though there is also an oil pressure warning indicator which I would expect would go off if the oil was low, causing low pressure. That’s not the case. Only the CEL is on.

VCDdriver - I do drive the car year round. When the weather is nice in the summer, I drive a vespa to work. I drive it all winter, most of the Spring and Fall, and in the summer for both weekend trips and whenever there’s a threat of rain I’ll take it to work. I definitely have not had 10 oil changes since I bought it, just the scheduled ones.

"though there is also an oil pressure warning indicator which I would expect would go off if the oil was low, causing low pressure."
Why do so many not read their owner’s manuals and not understand what this very important light means?
It won’t go off for low oil level. It only triggers for no oil pressure, which could be caused by no oil left or other issues. If the oil light comes on, it means that damage is already occurring. If you continue to drive, your engine will be destroyed in seconds. The oil pressure light does not eliminate the need for you to check the engine oil level!

Piston check = profit generator.

Remove spark plugs, shine flashlight into cylinders, verify existence of pistons, charge customer.

Or just charge customer. Same thing either way.

“there is also an oil pressure warning indicator which I would expect would go off if the oil was low.”

Why do people say that a warning light, or an alarm, or another type of warning “goes off” when they actually means that it “goes on”? This type of misuse of the language leads to a lot of poor communication with mechanics.

That being said, as tardis stated, an oil pressure warning light is just that–a warning of low oil pressure, NOT a warning of low oil level. Why, oh why, oh why do people not read their Owner’s Manual?

good to know. though you should know that the manual says the light means:

“Engine oil pressure too low - switch engine off and check oil level.”

It says nothing about “No oil pressure”

please see my other post. I quote the manual. I do read it.

Ahh - i missed something on the receipt. at the top it says:


No mention of pistons is made anywhere else, like down below where they list the actual things they did (oil change, check fluids, rotate tires, etc)

burst of smoke; check engine light

  That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P1234) not just their translation into English and post it back here.

I’m going to pick up the car in a couple hours. They’ve already fixed it. the problem was a failed exhaust purge valve. he didn’t do a very good job of explaining it over the phone, but I gather this valve failed, which is what caused the cloud of smoke to come out of the tailpipe, and subsequently the CEL to light up.

As for the “20,000 MILE SERVICE PISTON ENGINE” he says this is so they know “what kind of engine it is” – as in, “one with pistons.” (last I checked, VW doesn’t make anything but, so go figure…)