Another front end rattle question
 

All right, I just got new tires put on my 78 240D about a week and a half ago. When I first drove home with them on, I heard a new rattling sound while I either let off the gas or pushed in the clutch. When I got home, I looked around and noticed that the hood release must have been pulled, because the little hood-opener tab thingy was sticking out in the grill. I figured that the rattle was because the hood was partially open, and thought that was that.

Well, the rattle didn't go away. I thought it had at first, but now I'm guessing I was just listening to loud music and couldn't hear it. I have a problem with that sometimes, but that's another story.

Anyway, I have now determined the exact characteristics of this rattle. Are you ready? Here we go:

I can only hear it while coasting with my foot off the gas, or the clutch in like I said before. It also only seems to happen from around 40 MPH to 25 MPH. I've coasted at 50 or so, and can't hear it, but if I can coast down to 40~35 or so, it starts up, and doesn't go away until around 25 MPH. Very strange. Anyway, it seems to be coming from the front, and I'm pretty sure it didn't start until I got the new tires.

I took it back to the tire place (Les Schwab for those who care) yesterday to have them check it out, and they told me it was missing a lug nut. What? OK... I'm feeling less and less confident in their installation all the time. Why was my hood popped? Why did they not put on a lug nut? It's especially disappointing because I've been a long time Les Schwab customer in the Portland area, where they are excellent. Over here in Boise, they seem to be missing something. Anyway, they told me they put a new lug nut on, but didn't notice anything else.

I left without feeling very reassured, and the rattle is still there. It could be a coincidence, but I wonder if anyone has any ideas on what this rattle might be.

Thanks for reading my extremely long-winded post, those of you who have stuck with this...

Well, because of the rattle, you have had the lug nut replaced.

Have you looked under the car, to see if there is anything loose?

I gave it a cursory inspection. I figure I need to get under there and start pulling on things to see what's what. Obviously it's nothing that is easy to pinpoint since no one really gave me any ideas, so I'll just have to get down there.