Loud Fan Noises (Fan Continues to Run) After Engine Shut Down

Hello,

My name is Ben and I have a 2010 Jetta TDI Sedan. I was one of the "lucky ones" with the check engine light within 200 miles after getting my car due to a faulty O2 censor. This problem was fixed within about four days, and things have been good, until tonight. Now my car has 1650 miles and I may have another problem, but I wanted to check with you guys before calling the dealer.

Tonight after driving home from work and just after I turned my car off I heard a fan spool up in the engine compartment and it was really loud. It sounded like a belt and or fan and it was spinning really fast. It didn't sound like it was hitting anything or slipping/squeaking. So I had been listening to the radio while driving, the car was running fine, the engine was quiet, 15 mile drive home in 40 degree fahrenheit weather. as soon as I turned the car off the fan (or belt/fan?) spooled up. I've never heard this before, and honestly I didn't even really realize it was the car at first, I thought it was the climate control system in my garage malfunctioning at first. I got out of the car and walked up to the front and could hear that these noises were coming from my car. I got in and started the engine again, the sound went away, I let it run for a minute or so and everything sounded ok so I turned it off again. As soon as I turned it off the fan started spooling up again but not as loud as before. This time I opened the hood and walked up front to check things out. Seems like the radiator fan perhaps? Whatever it is it's below the alternator, and I could feel it blowing if I put my hand above the alternator.

I also noticed a bit of a burning plastic smell in and around the engine compartment. It wasn't an extremely strong smell, and it may be normal for a new car, but I wanted to point this out.

I left the hood open for about 10 minutes minutes and since it's trash night I took the trash cans to the curb while I waited to see if it stopped spinning. When I got back to the car the fan wasn't spinning anymore, so I closed the hood and went inside. I'm not sure how long it continued to run, but I would say at least 3 minutes, and maybe close to the whole 10.

Any ideas what is causing this? Could this be problematic?

Thanks for the insight everyone!

Totally normal. Look in the thread above entitled "2009-2010 TDI FAQ" or something similar.

You merely caught your car in the middle of a regeneration cycle.

Thanks for the reply!

How silly of me. I even read the FAQ when I bought the car and was wondering how many miles I would have to drive before my car did the regeneration cycle for the first time. I knew it was coming and when it happened I didn't realize that is what it was doing!

Does anyone happen to know how many mile intervals this happens in approximately?

alreadyBenBrott said:

Thanks for the reply!

How silly of me. I even read the FAQ when I bought the car and was wondering how many miles I would have to drive before my car did the regeneration cycle for the first time. I knew it was coming and when it happened I didn't realize that is what it was doing!

Does anyone happen to know how many mile intervals this happens in approximately?

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Mine seems to do it every month or so. I knew what it was because of this forum and honestly don't even really notice when it DOES do it, because I know it's normal.

alreadyBenBrott said:

Does anyone happen to know how many mile intervals this happens in approximately?

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There's a thread from last year somewhere around here, an owner kept a VAG-COM plugged in while he drove and reported a regen every 300 miles. (If I recall correctly)

it also depends on how you drive. if you keep the EGT high enough long enough it'll be spread out further.

You shut the engine off during a particulate filter regeneration.

Same thing happened to me tonight when I got home. It suddenly smelled like burning plastic as I pulled in the driveway. When I turned the car off the fan ran quite loudly for 5 to 10 minutes. So knowing now I probably interrupted a regeneration cycle is there anything special I should do the next time I start the car?

tiguando said:

So knowing now I probably interrupted a regeneration cycle is there anything special I should do the next time I start the car?

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Drive normally. The car is programmed for this scenario and will regenerate itself when it's needed.

alreadyBenBrott said:

Does anyone happen to know how many mile intervals this happens in approximately?

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for the beamers dpf regen is every 5-600 miles so it should be very close to the same for the v-dubs. mostly this will be very transparent to the driver.