Terrible engine noise cold startup
 

So this seems worse than lifters and Ive been noticing it's getting worse lately. I really don't think it's bottom end noise because it's been doing it for a couple months now and it hasn't took a shit yet. Runs and drives fine other than this noise. Could it be timing belt pulley or tensioner? Sounds like it's coming from right behind the cover but I can't be certain. Noise goes away once it's up to normal temp. I'll drive it around the block after dinner and take another clip to show how it sounds after.

Sounds to me like something rattling. Check for lose bolts, covers, fittings, etc.

Fingers crossed it's something simple! I'm going to bring it into work tomorrow and pull the valve cover and timing cover off and see if anything obvious jumps out at me

I'm thinking exhaust. That bracket that holds the downpipe to the tranny, the shield on the DP, top heat shield on the cat, etc.

Have the car up in the air and nothing obvious. There aren't any shields or braces on my artech exhaust so that's out of the question. Also disconnected the alt/wp belt and no change in the noise so it's definitely engine related. I drove it into work and took it to lunch and again, the noise subsided each time the car got up to temp. I guess next step will be popping the valve cover and timing cover off and see if anything looks loose/broken in there. Won't have time today so I'll have to get to that this weekend. I was supposed to bring the car to be tuned this week too ... Blah

Guess I found my noise!!!!

Attachment 184134

What did you find? What did I miss?

See the timing idler pulley? It's about to fall off and it's crooked and contacting the plastic cover. Lol I have a new one on the way I'm just going to leave the belt as is and swap the idler and tensioner pulleys out

Idler pulley. Either the bolt is way loose or the bearings are gone. Yikes.

Ahh, you must not have hosted it on MT.net. My employer blocks many file sharing sites. Logged on via phone and I see what you were talking about. Glad you have found your problem and you can rest easy.

Ahhh ok haha. Yeah I hosted from photobucket.

Yes I can definitely rest easy now knowing it's a simple fix and I will still be able to get it on the dyno next week. I'm anxious to swap the pulleys out and start it up and see if it's quiet lol

Well yup, that was it! Bolt backed out. Added some Locktite and torqued it back down. Started it back up and everything seems quiet! Off to Oracle tuning it goes this weekend!

I knew it involved a cover, somehow.

What has changed since your last tuning session? Going to dyno twice in a year... spendy!

No I actually never had it on a dyno! I finished the setup in October and Ive been driving it on the autotuned basemap ever since

Who had the other water cooled NA then? Was that a second of Harold's cars? I'm confused now. Lol.

What do you mean water cooled? Lol

Sorry, Air to water intercooled... I thought there was a second miata there that had that setup?

I'm just air to air intercooled... No air to water here haha

wow. someone with an issue who actually came back and reported the problem...