Check engine light on and radiator fan coming on at startup.
 

What's up people. I have owned my 02 A4 Q sport since 40K on it. It now has 70K and just recently my check engine light has been coming on. The weird thing was that one day I put gas in, the light came on so I thought that I didn't tighten my gas cap. This was happening when we had a couple really bad cold weeks And I mean high of 5 degrees cold. It eventually went off but now every time I start my car, I can here my radiator fan turn on and it is very loud. Since I have owned the car I have never heard the fan come on and now my check engine is back on again and the fan comes on at start. The car performs wonderfully and I have no indication that something is wrong except that little yellow light. I still haven't been in to the dealer ship just because of my money situation. Im still incollege and I have very little time and money. Im wondering if its the crank case breather hose because I know of the recall they had but my car shows no sign of boost leak. I would really appreciate your suggestions. Thanks.

RE: Check engine light on and radiator fan coming on at startup.
 

yo, it could still be your gas cap. mine does the same dam thing.. sometimes it goes on and mysteriously it will go off a week later. but the radiator fan is nothing to worry about either, my fan comes on quite a bit when its hot out. as long as everything is running ok you have nothing to worry about. you can run into an auto zone and they will pull your codes for free and than you have everything solved without stepping foot into the whack stealership

RE: Check engine light on and radiator fan coming on at startup.
 

You will have to run the codes and post them here. autozone will pull them for free

RE: Check engine light on and radiator fan coming on at startup.
 

Thanks for your help guys. I did think about going to auto zone. My light is on everyday now and it never goes off anymore. It went on and off for about a week and now its steady. I will keep you posted on what they say and I will post the codes. thanks again

RE: Check engine light on and radiator fan coming on at startup.
 

I went to autozone and it was code p0118. From what I have looked up it is the coolent sensor. This would explain why my radiator fan keeps going crazy when i start the car on. Anyone have any ideas.o ya, I called audi of naperville today about a wiper switch they installed back in nov (I was hit while I was turning my wipers on andthe impactwas so hard my handbroke the lever)and I told her that they forgot to hook up the motor for my windsheild fluid. she told me since it was so long ago they would charge me 150 to check what it was.

RE: Check engine light on and radiator fan coming on at startup.
 

I've got an '03 A4 1.8T with 70k miles and I've got the exact same problemas keebs as of yesterday. My car has been working well and I don't drive it hard. My check engine light came on yesterday - and twice since,after I start my car, I could hear the radiator fan working overtime - very noticable and I've checked under the hood to confirm. Its not the least bit warm outsite so it shouldnt' be working very hard, I'm convinced its related. Any thoughts or suggestions would be appreciated!

I don't have any codes so I may need to visit the dealership - my only problem is that its 80 miles away so its a nuisance - I may have AAA deliver it just in case.

RE: Check engine light on and radiator fan coming on at startup.
 

change the coolant temp sensor which is a guide to why the fan stays on all the time in most cases