'04 Mystery Noise

[FAMAJ]

Apologies - I'm usually annoyed by posts about noises (how helpful can you be without hearing it?) but here I am doing it. I would make a video but I'm away from the car. Anyway, my '04 with 126k has developed a sound in cold weather. The colder the louder. Before the car warms up, when shifting into D or R, a loud clanging emanates from what seems like the drivers side of the engine bay. I've looked but don't see any moving parts interfering with one another. The noise is not present in P or N. The noise is present in D or R while standing still or moving. It goes away after the car warms up. It does not seem to change with engine speed. I'm stumped. I've just spent lots of dough lately at the dealer and don't want to visit again. Any suggestions?

 

[Jrod]

Motor or transmission mount?

 

[FAMAJ]

Great suggestions. Is there a way to check them? Could I tell anything visually?

 

[TXLX100]

Could also be an exhaust heat shield. Which reminds me, I need to fix the intermittent clanging noise on mine.

 

[Keowee]

X2 for the heat shield if there is no noise after warmup.

 

[re_guderian]

yep, catalytic converter heat shield would be my first thing to check.

 

[TTO5]

As an assistant service manager at a large toyota dealership I feel like it's the heat shields on the pipes. Just remove all of them. I removed all of mine a couple years ago with no regrets

 

[FAMAJ]

Thanks everyone. Going to check it out next time I have time when the truck is cold!

 

[RND1]

Remove your engine cover and look on the underside to see if all the foam pads are intact? If you are missing a foam pad, the engine cover is coming into contact with metal in the engine bay. It makes a fairly strong vibration such that you would never suspect a plastic engine cover.

This also indicates you are probably due for a good throttle body cleaning.

 

[FAMAJ]

Sounds like I have a busy weekend ahead. I might need to ignore this for another week!

 

[Sandroad]

So this thought might depend on what you mean by loud clanging noise, but the pattern you describe is much like you'll hear with a cracked exhaust manifold.

 

[FAMAJ]

That's what I'm most afraid of. Wouldn't the manifold make noise even in P or N?

 

[Keowee]

^Most likely it would be a constant sound until it heated up enough to close the crack.

 

[FAMAJ]

The only problem is that to troubleshoot, the car has to be in gear. That means I have to have complete trust in my wife's ability to keep her foot on the brake and not think about my life insurance policy...

 

[RND1]

It will take you all of 5 minutes to remove your engine cover to see if the foam blocks have deteriorated. If so, leave the cover off and go for a drive. Vibration will be gone.

 

[Keowee]

You can reach under the truck to check both cat heat shields with a long wooden broom handle. Just push against each one to see if the noise changes or stops. Keeps you out from under a running car.
Then do the same on the engine cover. The exhaust manifold would have a ticking sound rather than a clanging. Do the broomstick on those heat shields too.