Little chain rattle/ valve tick start up

[lolcantturn]

Hey guys. I've had my car in storage since the summer where it was running 15w40. Bit too thick for NJ winters, but I drove around with this oil for about a week until I changed it yesterday. With the 15w40 I would have chain rattle/valve tick for about 10 minutes every time I started it up cold. Now that I changed to 5w40, I still get the same noise but for about 10 seconds when I start it up cold.

This never used to happen in past winters/in the summer. Always very consistent with my chain tensioner replacement intervals (with the last time being 2000 miles ago) and always change my oil on time, though I feel that by running the wrong oil this past week I may have damaged my timing components enough to now produce this rattle noise upon start up.

Is this necessarily bad? I'm driving my car across the country in a couple of weeks and I don't have the time to replace the timing components. The engine is still pretty young, at 101,000 miles.

[roguetoaster]

5w-40 should be okay to use and shouldn't cause any damage as long as you aren't abusing the engine. I personally run 15w-50 in winter (and most of the year) but top up with 10w-40 as needed. Yes, my engine can be a bit noisy on startup, but it quiets down after a minute or so. After three winters of following this protocol and replacing the tensioner around 30k miles I have noticed no visible cam wear or any other symptoms of damage.

I have previously run 10w-40, 5w-50, 15w-40, all of which had pluses and minuses, but now I just stick to one oil year round.

Your best bet is to just follow the manual regarding weight vs temperature. Don't worry about hurting the little M42 as they are far more robust than they are generally thought to be.