Why did my engine rattle with the AC on at 6k revs?
Car = MY01, Decat, Tek 3.
On the way home this afternoon I was in cruise mode, third gear about 40 mph with the Air Con on freezing cold !
As I came onto a dual carriage way I floored the accelerator into the carpet and kept it on WOT. At 6000 revs I heard rattling noises from the engine. I quickly lifted and the noise went. I slowed down and then floored the accelerator again, as the car went past 6000 revs it rattled badly.
I then switched the aircon off and tried it and couldn't get the same rattling noise, although I thought I could still hear something similar but quieter..
Have I broken it ?
Nathan..
On the way home this afternoon I was in cruise mode, third gear about 40 mph with the Air Con on freezing cold !
As I came onto a dual carriage way I floored the accelerator into the carpet and kept it on WOT. At 6000 revs I heard rattling noises from the engine. I quickly lifted and the noise went. I slowed down and then floored the accelerator again, as the car went past 6000 revs it rattled badly.
I then switched the aircon off and tried it and couldn't get the same rattling noise, although I thought I could still hear something similar but quieter..

Have I broken it ?
Nathan..
sounds like something to do with the AC, so check pulleys e.t.c.
all i will say is a ratteling comes from the engine resonating at a frequency to match that of say, a heatshield. this will then rattle.
Putting the AC on/off changes the stress on the engine, and so the frequency at which this rattle occours will be at different revs, maybe 6K with AC on but 8K with AC off (which you cant rev to).
is it only under load? if you can recreate it standing still get a mate to hold the revs and go around the engine touching various bits, if it stops you have found it
all i will say is a ratteling comes from the engine resonating at a frequency to match that of say, a heatshield. this will then rattle.
Putting the AC on/off changes the stress on the engine, and so the frequency at which this rattle occours will be at different revs, maybe 6K with AC on but 8K with AC off (which you cant rev to).
is it only under load? if you can recreate it standing still get a mate to hold the revs and go around the engine touching various bits, if it stops you have found it
I thought the AC compressor disengaged under heavy acceleration?? Maybe I'm making this up but I thought I read something about it in the owner's manual.
If so, having the AC 'on' shouldn't make any difference at 6000 rpm WOT.
If so, having the AC 'on' shouldn't make any difference at 6000 rpm WOT.
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