I was just getting ready to open my own
cold rattling 2.5 thread when I read this one. I love my 2.5 in every way but this winter, on the first 20 degree F day I noticed what sounds like major lifter or cam chain noise for about 5 minutes after a cold start. Today it was 3 degrees F outside and she had been sitting in the work parking lot for about 6 hours. Man, that was really noisy, much noisier than at 20 degrees F. After 5 minutes of slow running she got as quiet as she runs on a hot summer day... Q-U-I-E-T. Above 20 degrees she is quiet as a mouse (32 degrees F ambient).
My oil and filter was dealer installed about 3,000 miles ago. My oil is down only about 1/16th of an inch. I suppose in warmer weather it would show FULL. I have 26,000 carefree miles on the car.
I'm sure we had some 20 degree F days last winter when she was 6 mos. old or so, but last winter I never noticed the noise I am getting now.
Here's what I'm thinking. The only thing I've had done which COULD relate to this problem is I had a TSB done a couple of months ago (in warmer weather). They reprogrammed the ECU which removed a 1-2 second rattle upon late Fall cold start-up. I reported to you that to my surprise it cured the timing chain rattle. Now I'm wondering if this reprogram is somehow connected to my 5 minute rattle. I'd rather have a 1-2 second rattle than a 5 minute rattle. Something can't be right here but I've heard other say dealers have said this is normal for the 2.5. One guy said he challenged the dealer by asking to start up a new 2.5 on the lot. He said that the new car with less than 15 miles on it also had the rattle upon start-up and for several minutes thereafter on that particularly bitter cold day.
I'm curious, are there many of you out there with '07-'08 2.5's that have
not experienced this rattle? Do any of you run full synthetic and still have this problem.
I'm starting to get hot and pissed just writing about this. I have never owned any vehicle that displayed this engine noise in very cold weather, including a '61 Corvair and a pos '74 Pinto.

So before I haul her in to the dealer what have been your experiences this winter?