Hi, i recently bought this car and have a ratteling noise in manual mode only noticed mostly during idle once the car is warmed up. I noticed that one of the transmission cooler lines is vibrating hard i beleve causing the ratteling noise. The hose vibrates harder at the transmission and calms down some at the cooler but not gone. Not really sure why it is vibrating like it is...may normal? Any ideas would be greatly appriciated.

Also does anyone know what the part numbers would be for the transmission cooler line adaptors. The quick connect fitting have been removed and replaced with the 6an adaptor. I am just wondering if they used the correct fittings there.

This noise only noticed in manual mode at idle and when you come to a stop. Regular drive mode is fine.

2005 Grand Prix GXP
4T65-E HD MN7
External transmission cooler
6AN braided line from transmission to cooler bypassing the radiator
There are no other mods that i am aware of.

What level is the transmission fluid at?

Are you absolutely sure that it never happens in non-manual mode under the same conditions?

How many miles on the car?

How many miles on the spark plugs?

the 2004-end grand prixs with manual shifting trans have bad reliability, 120k with nice behavior is expected out of the trans. its weird it ONLY does it then.. but the filter is special on that trans and you do NOT want to use a generic one of any kind. There are also a few things that should happen at the panf filter and duifferential lube pipe, but i wont say them unless you plan to go in the pan soon

How did you plumb the cooler? Vibrations make me think changing pressure and volume. Pressure regulator? Shifts normal?

If it is a GXP then it came with a factory cooler. Maybe that'* what ozias is talking about. If one was added, then I'd be curious of this as well. Either way, tomorrow marks one month with no answers to my questions above so I'm guessing this thread has been forgotten.