Piston Slap: The Affordable VAG-COM Dongle Tool?

Dan writes:

Dear Sajeev,

I’m looking for some advice on a reliable, yet affordable OBD-II scanner to look up and clear the check engine light (CEL) on my 2010 Volkswagen Golf TDI. While a dedicated Ross-Tech VCDS would be ideal, the price and future ownership of this (or any other VAG) vehicle is not.

Emissions issue aside, the Golf has been reliable except for having to replace several tires (and one wheel) over the years due to pothole-riddled roads. Besides regular maintenance, I’ve replaced a glow plug ($120) and the CEL has recently returned yet again. I suspect another glow plug is to blame.

Onto my question: What do you think of one of these wireless/Bluetooth dongles that work with a smartphone app? I’m leaning towards one of these as they seem to offer more options than the traditional cabled versions. Can you or the readership recommend a good iOS/Android app?

Sajeev answers:

The VAG-COM is not a system for casual wrenchers with a “normal” OBD-II scanning budget. Even older VWs have trouble with cheap ( $50-ish) and really cheap ( under $20) code scanners. If there’s a decent 2010 VW code scanner or dongle and software package for under $150-ish, my Google-fu ain’t savvy enough to find it.

Ross-tech is your best bet, but not the free software for older models. I wouldn’t even trust a generic dongle unless you’re computer savvy enough to find the right (laptop) drivers. Perhaps consider the Ross-tech cables too. Unless you read otherwise about a fantastically magical generic VAG-COM dongle and/or software on the TDI forum, of course!

Or just have the person at Autozone scan it for you. You can probably convince ’em to clear the codes if you come back later and say, “I fixed it, can you clear it for me?” Whether or not you actually fixed the problem is a whole ‘nother story.

Or don’t listen to me, because following up with Dan yielded this:

I did go with a wireless OBD-II scanner. I tried a few of the free apps and settled on OBDCarDoctor (iOS). The CEL turned out to be a faulty exhaust valve flap covered under extended warranty.

While I will take the deal from VW to sell back the car, I’m in no rush to do so. It’ll be bittersweet to let this car go.

[Image: Shutterstock user Zeynep Demir ]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.