# Technician removed air filter, damage done? **URL:** \ **Category:** Factual Questions\ **Created:** [September 15, 2016, 11:35pm UTC](https://boards.straightdope.com/t/technician-removed-air-filter-damage-done/766050 "2016-09-15T23:35:42Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Jacqbean](https://avatars.discourse-cdn.com/v4/letter/j/ee59a6/32.png) [@Jacqbean](https://boards.straightdope.com/u/Jacqbean)\ **Post date:** [September 15, 2016, 11:35pm UTC](https://boards.straightdope.com/t/technician-removed-air-filter-damage-done/766050/1 "2016-09-15T23:35:42Z")
A technician did some work on my car (Hyundai Elantra) a few weeks ago. I noticed that since then, the engine sounds have been louder than normal. I was able to get the car back into the shop and it was realized (by another technician) that the engine air filter was missing. The last person who touched the engine was the first technician, so I am assuming he took it out and didn’t put it back in. So I drove it approximately 1700km with no air filter. How much damage could have been done to my engine in this amount of time, and how long could it take for damage to be evident? ---
**Author:** ![Yarster](https://avatars.discourse-cdn.com/v4/letter/y/7c8e57/32.png) [@Yarster](https://boards.straightdope.com/u/Yarster)\ **Post date:** [September 15, 2016, 11:45pm UTC](https://boards.straightdope.com/t/technician-removed-air-filter-damage-done/766050/2 "2016-09-15T23:45:09Z")
It’s impossible to answer that question without knowing the driving conditions of those 1700km, but I would guess the damage is basically none unless you drive through sand storms or areas with lots of air pollution/forest fires. ---
**Author:** ![Jacqbean](https://avatars.discourse-cdn.com/v4/letter/j/ee59a6/32.png) [@Jacqbean](https://boards.straightdope.com/u/Jacqbean)\ **Post date:** [September 15, 2016, 11:52pm UTC](https://boards.straightdope.com/t/technician-removed-air-filter-damage-done/766050/3 "2016-09-15T23:52:09Z")
Most of the driving was in the city (Ottawa) on paved roads, about half of the kms in heavy traffic. The rest was on country roads with minimal traffic. ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [September 15, 2016, 11:52pm UTC](https://boards.straightdope.com/t/technician-removed-air-filter-damage-done/766050/4 "2016-09-15T23:52:46Z")
Change your oil right away. Any dirt or grit that should have been caught if the air filter was in place has made it into the combustion chambers and the rest into your oil. Probably no permanent damage, but change the oil and clean the air intake an MAF sensor. ---
**Author:** ![JerrySTL](https://avatars.discourse-cdn.com/v4/letter/j/e274bd/32.png) [@JerrySTL](https://boards.straightdope.com/u/JerrySTL)\ **Post date:** [September 16, 2016, 1:19am UTC](https://boards.straightdope.com/t/technician-removed-air-filter-damage-done/766050/5 "2016-09-16T01:19:53Z")
As Yarster said, if you were driving in a dust storm, I’d be worried. Probably no damage though. However keep a written record of the incident just in case. Also the Elantra has a 10-year, 100K mile warrenty in the USA. If it’s the same in Canada, then you really don’t have to worry too much until then. ---
**Author:** ![jasg](https://avatars.discourse-cdn.com/v4/letter/j/f0a364/32.png) [@jasg](https://boards.straightdope.com/u/jasg)\ **Post date:** [September 16, 2016, 1:21am UTC](https://boards.straightdope.com/t/technician-removed-air-filter-damage-done/766050/6 "2016-09-16T01:21:21Z")
Don’t worry unless you were off-roading in the desert or in a sandstorm. Many of my friends have race cars run a season or two with no air filters. As noted, put a filter in place and change your oil a bit early. ---
**Author:** ![Me\_Billy](https://avatars.discourse-cdn.com/v4/letter/m/e480ec/32.png) [@Me\_Billy](https://boards.straightdope.com/u/Me_Billy)\ **Post date:** [September 16, 2016, 4:07pm UTC](https://boards.straightdope.com/t/technician-removed-air-filter-damage-done/766050/7 "2016-09-16T16:07:37Z")
My air filters are quite clean if driving in a city. But get all sorts of crud, grass, hay, etc. when driving in the country. ---
**Author:** ![Whiskey\_Dickens](https://avatars.discourse-cdn.com/v4/letter/w/9fc348/32.png) [@Whiskey\_Dickens](https://boards.straightdope.com/u/Whiskey_Dickens)\ **Post date:** [September 16, 2016, 7:25pm UTC](https://boards.straightdope.com/t/technician-removed-air-filter-damage-done/766050/8 "2016-09-16T19:25:40Z")
Another vote for almost certainly no damage. The combustion chambers probably did a fine job of taking care of any particles that made their way through. **Dallas Jones’** suggestion of changing the oil is a great one. ---
**Author:** ![Tired\_and\_Cranky](https://avatars.discourse-cdn.com/v4/letter/t/a87d85/32.png) [@Tired\_and\_Cranky](https://boards.straightdope.com/u/Tired_and_Cranky)\ **Post date:** [September 16, 2016, 7:43pm UTC](https://boards.straightdope.com/t/technician-removed-air-filter-damage-done/766050/9 "2016-09-16T19:43:40Z")
> [@Jacqbean](#): > > A technician did some work on my car (Hyundai Elantra) a few weeks ago. I noticed that since then, the engine sounds have been louder than normal. The air intake generates a lot of engine noise and, without the filter, I’d imagine the intake noise might increase a bit, accounting for the extra noise you heard. Did the engine return to normal as soon as the air filter was replaced? I’m with everyone else that there was probably no damage.