: Noise on Startup when Cold

02-24-08, 08:43 AM
I have a 2005 STS with about 22,500 miles. When it sits for a week or so it makes a loud noise when started. It only lasts for a second or so and it's different from any engine noise I am familiar with. I will try to remember to open the hood next time and see if I can localize it. It goes away instantly and does not come back unless the car sits for another week or so. I wonder if it is just the valve train making noise afer the oil drains back. Anybody else have this noise? Normal? I could never take it to the dealer for this unless I wanted to do without the car for at least a week. Using M1 5W-30 oil all it's life.

02-24-08, 05:24 PM
Just a guess but does it sound like maybe the armature in the starter is hanging up?

02-24-08, 06:41 PM
I thought about the starter, it didn't realy sound like valve train noise. I just tried it today after sitting for three days and it sounded fine. Guess I will have to let it set longer and then try to pinpoint it with the hood up. The only two times it has done it were after it had set for a week or more.

02-26-08, 12:31 PM
Maybe a critter made a home in your engine while not in use. I have to remove them and nest from just about every engine in the barn.