Hi Group. I just bought an 01 CLS with 96000 kilometers a couple of days ago. The car ran great on the test drive but now suddenly the check engine light is on and I'm getting a humming noise while idling. The humming is coming from somewhere under the air filter area. I pefered buying the car completely stock, it is except for the air filter. The young man that had it put a round K&N filter on attached with a hose clamp, the original rectangular box is gone. Anyone have any ideas? If I need to check out trouble codes is the dealership the only place to go?

Thanks

 

If you dont have a OBD-II scan tool go to Autozone, they will read what the DTC is that is causing the check engine light to be on for FREE. If it is not related to anything that sounds detrimental then you can clear the light by removing the negative battery cable for 20 seconds or so and then replace it. If the light comes back on again you will probably want to have it checked out.

 

I bet the humming noise is just a result of the rigged up intake filter. If you don't have the original air box I don't think there is much you can do but get used to the noise, or maybe by an after market cold air intake?

 

Thanks guys, I'm off to the dealer in any case, since I just got the car I'll change oil and trans oil, timing belt and waterpump. I'll see what they say about the humming/hissing and post the results....here goes my first grand hopefully all will be good after.

 

Well just got off the phone with the dealer, my new to me low milage CLS is going to cost a few more bucks to be near perfect. Heres the list:
- Original air box (from the scrap yard)
- Timing belt and water pump
- Oil change
- Trans oil change
- Injector cleaning
- Brake fluid flush
- Evap canister
- Linkages and bushings

So over 2 grand later, this car better be mint after!

 

talk about the definition of dealership rape.


- Original air box (from the scrap yard)
If you have a CAI in there, just leave it. A CAI (cold air intake) will make more noise then a stock airbox. post a pic for us so we know if its a CAI or just ghetto rigged.
- Timing belt and water pump
Only necessary once your past 105k miles. not sure what that converts to in KMs. I just had mine done and my mech said i could have gone another 20-30k miles.
- Oil change
DIY
- Trans oil change
DIY
- Injector cleaning
DIY with seafoam
- Brake fluid flush
can be DIYed
- Evap canister
sounds emissions related. I havent heard of members servicing this but it might cause your CEL (check engine light) to have gone off. best bet is to read the code from the CEL.
- Linkages and bushings

 

The air box was DEFINITELY getto rigged, a round K&N filter attached to the rubber hose with a hose clamp and a tie wrap to keep it somewhat in place . Your right about evap canister, it was the cause of the check engine light. I'd love to DIY some of these things but we're in the throws of winter in Canada right now and I don't have any garage space to work indoors.

 

DO NOT let them change your timing belt yet, from what I've heard, all the dealers and other people on here(mainly from the US) are told and know to change this at 105xxx miles, which works out to be around 168xxx km so you are a loonnnnnggg ways off from needing this done, my dealer told me I needed to have it done at 65xxx km which is just a reason for you to pay them. get a real CAI, its totally worth it considering you need something anyways, and for the rest if you cant do it yourself find a cheap shop to do it because the dealer charges way to much for this shit.