Hi All,
I have a 2014 Q60S, but it is the same thing as the G37 and I was wondering if anyone
with either the G37 or Q60 has this issue. When I start my car after sitting for several hours
on a cool day, their is a rattling sound that lasts for about 20 seconds, then the engine
slows down slightly and the noise goes away. I can rev the engine back up to the start
up revs and it will no longer rattle. This rattle is different then that timing chain rattle
in my older 2004 350Z. It sounds more like the exhaust has a leak or something. I had
listened to another Q60 of the same year and it did this as well. My car has only 9300
miles on it. The noise reminds me of the old American V8's of the late 60's and 70's
which would rattle because of this exhaust valve that would close and cause exhaust gas
to go through a passage in the intake manifold until the engine warmed up, then it would open
and the thing would be dead quiet. Does this VQ37 engine employ some thing like this
to possibly heat up the converters, or some part of the engine block? The car only does
it when started after it is completely cold. I just would like to know if this is normal
or if I have something to worry about.