Loud rattling noise when I start the engine

[Dtownwolfpack]

First, would like to wish everyone a Happy New Year!!!

Now for the emergency, I am not sure what happened but felt something break on the engine a month ago, started rattling hard knocking sound in the engine. No idea what it is. Every time I start it now, it sounds horrible and loud rattling sound. At first I thought it was the header but there’s no smoke coming out of the engine bay. Someone suggested that it might be the pistons? Anybody have any ideas? If it is the pistons, what am I looking at as far as repair? Thanks guys!!

Dtownwolfpack.

[joeybananaz18]

Can we get a clip of what it sounds like?


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[DeathTrap]

Yep. Upload a quick video and see if you can narrow down the location of the sound.

If it only happens on start up, I'd be willing to say timing chain related parts.

[Dtownwolfpack]

Here is a short video with sound

https://share.icloud.com/photos/0pN0GoWULacgwAvL9zSOd9Ipw

Not sure if this will work

Thanks

[BMWCurves]

Here are Dtownwolfpack's videos in streamable form (so you don't have to download):

Video 1 (https://streamable.com/rmgx3)

Video 2 (https://streamable.com/gxz8e)

[Sockethead]

Almost sounds like an exhaust leak. Is it louder on the exhaust side? Perhaps something with the SAP is shot

[Dtownwolfpack]

Almost sounds like an exhaust leak. Is it louder on the exhaust side? Perhaps something with the SAP is shot

It kind of does sound like it’s further back in the engine. If you rev the engine the rattling sound just gets faster. And there’s quite a bit of loss in power when you put it in gear. But the car will idle with no problem, just a lot of knocking, rattling sound as you can hear in the 2nd clip.

[Sockethead]

Does it go away after it warms up or is it always there

[joeybananaz18]

This may be a dumb question but are all 6 cylinders firing?


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[Sockethead]

I would think that it would throw a code for that...
I just listened to it again and I swear it sounds like a massive exhaust leak.. Can you make another video clip giving it a little throttle and letting off?
When it first appeared, what exactly happened and what were you doing? (accelerating, decelerating cruising...)

[Dtownwolfpack]

Does it go away after it warms up or is it always there

No, unfortunately it does not go away.

[Dtownwolfpack]

I would think that it would throw a code for that...
I just listened to it again and I swear it sounds like a massive exhaust leak.. Can you make another video clip giving it a little throttle and letting off?
When it first appeared, what exactly happened and what were you doing? (accelerating, decelerating cruising...)

I will try and make another video later, but here’s more info,I was driving to work and I noticed that the clutch wasn’t engaging, like it was missing from time to time when I was driving for that 40 minutes in to work. I thought I was going to be in trouble on my way home but nothing happened until I got to my subdivision and I wasn’t driving it hard at all, something just felt like it popped and started making this noise. It’s been there ever since.

[Sockethead]

I will try and make another video later, but here’s more info,I was driving to work and I noticed that the clutch wasn’t engaging, like it was missing from time to time when I was driving for that 40 minutes in to work. I thought I was going to be in trouble on my way home but nothing happened until I got to my subdivision and I wasn’t driving it hard at all, something just felt like it popped and started making this noise. It’s been there ever since.

That changes things... sounds like you may have lost some of the friction material off the clutch disk or a failure with the pressure plate... so hard to diagnose from a chair in front of a PC. You said you had a loss of power, was the car revving but not moving as it should? That would be clutch slippage...

[Dtownwolfpack]

That changes things... sounds like you may have lost some of the friction material off the clutch disk or a failure with the pressure plate... so hard to diagnose from a chair in front of a PC. You said you had a loss of power, was the car revving but not moving as it should? That would be clutch slippage...

If it's the clutch, would it make this noise while it's on neutral and just idling? Possibly? I just had the clutch replaced last year, although i put a lightweight aluminum flywheel with a standard clutch. Could that be the problem. The pressure plate is worn out?

[az3579]

That sounds like an exhaust leak to me. It's loud on the manifold side where the exhaust is. I would check all components in there (such as that valve thing that's near the SAP), make sure spark plugs are seated all the way, ensure there aren't leaks in the manifold, O2 sensor tightness, etc.

[Fried_Chicken]

+1 on Exhaust leak

[Dave1027]

That sounds like an exhaust leak to me. It's loud on the manifold side where the exhaust is. I would check all components in there (such as that valve thing that's near the SAP), make sure spark plugs are seated all the way, ensure there aren't leaks in the manifold, O2 sensor tightness, etc.

+1 to this. Especially the spark plugs. I've seen this same sort of thing caused by a spark plug that had blown out of the head and was just resting there, bouncing against the compression.

[Dtownwolfpack]

Hi Guys,

I finally had the time and the weather had been warm enough to diagnose this problem I have. Thanks again for all the help, you guys are awesome!! So after checking out a few dog the things that you guys suggested, first the exhaust leak, which I checked first and couldn’t find any leaks. So next I went to the other suggestion that a spark plug may have come loose and lo and behold that was exactly the problem!! I was so excited to find out that it was only the spark plug. Easy fix right?? Just replace it and everything is good! Wrong!!!! I was a dummy assuming it was an exhaust leak that throughout winter, I kept starting the car every so often and let it warm up. What I didn’t realize was the spark plug was loose and kept ramming back and forth against the opening. This caused the threads of the head to strip. Needless to say, I had to do a helicoil installation, once I finally got the right tool of which by the way, you need the long spark plug repair kit, $40.00 on debay. Everything went smoothly. Just used some grease on the tap so as to limit the shavings that goes inside the head. Once I see Natalie’s the helicoil with a little bit of high heat thread sealant, everything else was a piece of cake and it started right up! Thanks again to all of you for all your suggestions, it definitely made diagnosing it so much faster. Just wanted to let you guys know in case someone runs into this same problem.

Dtownwolfpack

[johnrando]

Glad to hear it worked out.

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