Help: loud rattle noise from intake manifold area when accelerating

[hungt1999]

Hello, I have a 1996 Corolla 5-speed, 212,000km

In the last few days, I have a loud rattle\pepping sound that seems to come from the intake manifold area. It happens only when I rev the engine or when I accelerate. It does not do it when running at idle speed.

The noise is similar to the sound produced by a leaky exhaust pipe. At first, I thought my exhaust manifold was cracked or that I had a leak in the exhaust pipe. But when I opened up the hood to inspect, the noise does not come from the exhaust manifold at all. It seems to come from the intake manifod plenum or somewhere on the back of the engine near the firewall

Otherwise the car is running good. I have no loss or power or anything, just the rattle\pepping sound is loud when I accelerate. Hopefully I won't get a ticket.

Please help me diagnose further this problem

Update:

sometime the noise source can be misleading, upon really close inspection, the rattle noise come from the flexpipe underneath. I think it is leaking or cracked.

I don't want to spend to much as I intend to keep the car only another 6 months or so. If I sucessfully locate the crack, does it exist a glue or potty that I can use to temporarily patch the crack?

thanks

[REN69]

could be the manifold heat shields, which you can just unbolt and take off... if that doesn't work then it could also be the catalytic converter heat shield. either way it's most likely one of the heat shields.

[speedy25]

I have not found a way to repair the flex pipes. Best bet is replacement. There are a few sizes of the flex joints available but I dont know if there is one to fit our cars and THEN you still have to do some fabrication to install it.

-SP