Hi everyone,

I probably should have joined Maxima.org much sooner but I was planning to mod my Max a little to show it off, but now, I don't know if I'll be doing any modding because I'm worried to death about an engine knock on startup.

I'm 18 and bought this car with 77k miles back in September. It's a 2005 SL. Two owner car, well-pampered and taken care of. Older couple bought it originally in their 60s and sold it to some people who I sort-of know who now sold it to me. I'm at 82.5k now and started my car this morning as usual in about 35 degree F temperatures and drove to school. Everything was normal.

When it was time to go back home at 3PM today, I started my car and let it idle for about 2-3 minutes. Started the drive home and 10 minutes into my drive, I noticed the car sounding like a diesel accelerating. Coincidentally, there was a Chevy Duramax right behind me so I didn't think anything about it. I got onto a road by myself and continued to hear this noise and became worried. However, the car still functioned as normal and couldn't tell any difference. It appeared only to happen when the car wasn't accelerating.

As I got home, I got out of the car and heard the frequent "knocking" sound of the engine. For the record, I have always ran 90+ octane fuel since I have owned the car and oil has been changed with about 1000 miles remaining on this cycle.

My Dad got home and looked into it, originally thinking it was a water-pump issue but as we did some research, I'm seeing a common issue being a timing chain or timing chain pulleys / tensioner. Below is a video of the knocking I took earlier today.

https://www.youtube.com/watch?v=Y6NujuIB79A

I'm taking it to a mechanic who is my friend tomorrow to have it looked at.

What do you guys think?

 

The timing chain tensioner guides failing is well documented and the sound is quite different than a knock. Plenty of vids on youtube. Let us know what mechanic says.