A&Q about 350Z
Q:
When i start my mk3 from cold it makes a whining noise for a bit until it heats up a little. It sounds like its coming from the outlet manifold part of the exhaust. So im thinking ive got a hole or leak in it somewhere!!!
The whole exhaust on the car cant be anymore than 18 months old, all looks like new right the way through but i doubt its genuine vw as its noisey, back box sounds like its a big boy racer thing but its just standard. Is it going to be worth going to vw and getting a new exhaust put on, hate driving around and sounding like ive got a massive back box on it, not into the noise! any other ways of quietening it down??
A:
maybe its the warm air intake plunger thing opening in the air box. it makes the box breath from the hole at the back (ie by the exhaust man.)
as for the rest of the exhaust, it could be just a blow part way along the system, if you get under the car you may see soot (or a darker patch) where its blown a seal (mine had that just by the entry to the middle box. when i decatted it they resealed that for free
A:
If it's like every car I've ever had, the warm intake tract will take hot air from round the exhaust manifold, but it shouldn't be exhaust gas (would clog your air filter pretty quickly). Exhaust manifolds tend to make tick-tick noises if slightly loose.
If you haven't done it already, check the manifold nuts are tight, as it could be loose when cold, but expands to fill the gap when it warms up.
A:
My exhaust manifold was loose, and it did indeed make a ticking noise that sped up with revs.