Hello all, I have asked this question and searched so many times before but I still haven't gOtten an answer. I know for a fact it's not a heat shield. The motor is a stock d16y7. AbOut 144,xxx miles. I have been experiencing this almost since I got it 2 years ago. Doesn't affect anything other than an annoyance. It happens when I'm going from 1st -5th gear. It's a rattle like someone is shaking coins in a can or something. I notice it mostly goes away after about 3k rpm. It occurs mainly when hot. When the motor is cold it doesn't occur like when it's hot. It will happen alsO when im in 5th going like 40 mph and I Put my foot down full throttle. Doesn't happen at idle. Can anyone please give me more answers than heat shield. Thank you

 

spark knock maybe why are you shifting from 1st to 5th ?? try using more of your gears. and maybe don't try to accelerate in 5th down shift first .

 

Haha no I didn't mean I go from 1st-5 th. I meant all the gears 1-5 haha

 

bahahaha. in all seriousness tho, have you checked to make sure that nothing in your engine bay is loose? for example my cai knocks against part of my fender well. that was, until i ziptied it lol. does it sound like its in the engine or what?

 

Yea I tried checking things. Umm the first cat was replaced under emmissions warranty last year so I know it's not bad. It kinda sounds like how if u are about to stall the car out it starts to rattle as it stalls out. Like if u let the clutch out slow and let it stall it will start to rattle. It's that kinda noise.

 

* its when I'm accelerationg

 

No one? I know there are very intelligent people that could be helping me!

 

its a cracked exhaust manifold. probably underside where you cant see it.

Ive seen this before, theres a small leak and what your hearing are the valves smacking. when its cold, the metal is compressed, but when it heats up it expands making the crack large enough to hear the valves during a set rpm range.


get some PB blaster and let the bolts soak at the merge overnight. Then pull off the manifold and look for the crack.

either replace with ebay d series header or grind it and re-weld it. Buy another manifold gasket if yours is messed up and boom, ur done.

 

is your heat shield loose ? what was wrong with your old cat ? if it was broken up could be some still stuck down stream . if you didn't find the cause of the failure the new one could be bad also.

 

This does make sense. But I had literally everything replaced by Honda for an emission recall. They replaced the manifold the cat the 02. Everything down the downpipe. So I don't know why it would be happening still. I thought it was gonna go away when I got all that done but it was still there.

 

Does it do it if you just rev the engine? Im thinking its a loose/broken exhaust heat shield it happens alot on these cars

 

no it does not ^^

 

try tightening the exhaust manifold bolts?

 

I'll Try that tomorrow.

 

Im still pretty sure its a crack or leak in the cast manifold..

even tho its thick cast, they still crack.. And even if honda "replaced everything" under a recall, i doubt they changed the manifold. If they were supposed to, Im betting they didnt to save $$$ since they dont profit from recall work. And they prob didnt inspect it closely for a crack and just looked it over or they didnt take it off the head at all.

They dont call it a stealership for nothing.

Im betting its a crack on a 16 year old manifold.

 

Could this have anything to do with the clutch/throw out bearing/fork

 

Does it happen only at a certain RPM? Use a screwdriver as a stethoscope and find where it is

 

^^

Yea, and only under load im betting.. so that throws that theory out if it is


fork and bearing? where does the sound come from.. underneath or towards the front?

 

Rev the motor using the throttle body and see if you can hear anything. It could be anything from the timing belt tensioner failing to something loose in your valvetrain. You need to pinpoint where it's coming from or else we're all just taking stabs in the dark at solving your problem.

If it's only under load I don't see it as something loose, because those vibrations can be simulated without a load.

 

It does not occur if I just rev the engine. I think it's something with the clutch. Because the noise is the same as when u are about to stall the car it starts rattling. Same thing. I think my engine is super solid. It doesn't run bad or anything. I don't need to even top off Between oil changes. And when I Fo change it it's still golden. That leads ne to believe everything mechanically is working well
In the engine. Correct me if I'm
Wrong

 

well, we dont know what the problem is, especially if your not sure exactly where the noise is coming from.

If you cant figure it out, then its time t go to someone who can

 

Congrats, you don't burn oil. Doesn't mean the tensioner isn't failing. But if its been fine for 2 years just drive it until something happens/gets worse

 

Yes I know it doesn't mean it's not failing. I meant internally I think everything is working good. I guess I'll just deal with it. I have no clue what it is. All I know it's coming from the front of the car.

 

I can say when more people are in the car the noise gets a little worse.

 

this