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I have a new rattle that I can't figure out

1365 Views 12 Replies 7 Participants Last post by  NorCalTacoma
My truck has developed a rattle/knocking sound recently and it is strange. I only hear it when I'm accelerating off from a stop and it goes away when I pass 15mph. It doesn't matter if I accelerate hard or gently, the rattle is there until I pass 15mph.

I don't think the engine is rattling because there is no rattling when I'm reving it in park. I even loaded up the engine by putting it in drive, holding the brakes, and gently reving it up to 1500rpms or when the tires are about spin.(power braking :D )

I don't want to take it to the dealer because I would have to put my stock suspension back on, otherwise they might say the rattle is caused by my lift which it doesn't seem like.

I did a search and found some people had the intake rattle which is happening in the same area as my rattle. However, the TSB says the rattling happens in reverse but mine is not doing it in reverse. So I am sort of at a lost here. Any ideas?
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What you could do is lightly with your fist thump around in the area that you think the rattle is coming from in the engine bay.
I just installed a TRD CAI and it seemed to make a horrid noise when it went through the power band. I did some thumping around the intake and found that the housing of the TRD Intake was coming into contact with the inner fender just at the rear corner. Installed a rubber bushing and the sound went away.
So try that? Just slowly thump around with you fist and see if you can I.D. any sort of noise that might be the culprit.
Good luck!!
Also check the exhaust hangers.
I was tapping and wiggling the intake and it doesn't seem to be loose or make any noises. However, I noticed there is a foam gasket between the intake and the fender. Could this foam gasket be insufficent at isolating the intake from the fender causing the rattle?

I haven't had a chance to check the exahust yet so I will do that later.

What are the chances it could be a CV since it seems like a speed related problem? Could CVs be making rattling/knocking noises when they are bad?
Hans Moleman said:
I was tapping and wiggling the intake and it doesn't seem to be loose or make any noises. However, I noticed there is a foam gasket between the intake and the fender. Could this foam gasket be insufficent at isolating the intake from the fender causing the rattle?

I haven't had a chance to check the exahust yet so I will do that later.

What are the chances it could be a CV since it seems like a speed related problem? Could CVs be making rattling/knocking noises when they are bad?
Yes, the foam gasket is insufficient and that's what causes the intake to make that damn annoying noise. Although this may not be your issue here. I would pop your hood, drive it forward a bit and have someone listen for where the noise is coming from. That is how I diagnosed it was my intake. Oh, and the intake rattle didn't only happen in reverse. The intake rattle sounds like cards going through bike spokes, but a little deeper.
musubi said:
Yes, the foam gasket is insufficient and that's what causes the intake to make that damn annoying noise. Although this may not be your issue here. I would pop your hood, drive it forward a bit and have someone listen for where the noise is coming from. That is how I diagnosed it was my intake. Oh, and the intake rattle didn't only happen in reverse. The intake rattle sounds like cards going through bike spokes, but a little deeper.
YES, my rattle also sounds like a card going through bike spokes. I know the intake TSB replaces the hose, but does it also replace that foam gasket?
Hans Moleman said:
What are the chances it could be a CV since it seems like a speed related problem? Could CVs be making rattling/knocking noises when they are bad?
Last time I saw CV problems, they showed up while turning, not while going straight. But that wasn't on a Tacoma
Hans Moleman said:
YES, my rattle also sounds like a card going through bike spokes. I know the intake TSB replaces the hose, but does it also replace that foam gasket?
I'm actually not really sure if the TSB replaces the foam gasket. I've never done it, plus I replaced my stock intake with the K&N intake. However, I would suggest unbolting the intake tube, shifting it around a bit, and re-bolting it back down. Since I used to take out my stock intake here and there (for random reasons), I've found that sometimes I'd put it back and the noise would be gone! Try it and if it doesn't work then, use the TSB. This is all providing that it is the intake hose
i'm gonna loosen and move around the intake after work and see if that does anything
The intake was not rattling, it was the engine. I filled up with 91 octane fuel yesterday and the rattling is gone. The previous tank of gas was probably bad because I never had any rattles from 87 octane. Or maybe my engine is running leaner now, after break-in so 87 is causing the rattles? I will try 89 octane the next time and see what happens.
Glad the rattling is gone for now:thumbup:
Premium all day!

Premium is bank up in SF. Just fill 89 and you will be fine. No problems here! :thumbup:
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