Pinking

[Amber]

Gidday, I have a 3.1 diesel auto. Concerning Highway driving. When under load going up hill it starts making noises like petrol pinking or diesel knock (like when you labour down a manual box). I don't think the auto is changing down early enough when in overdrive and it is labouring down to much. Does that make sense?
The auto appears to have 2 definate stages of overdrive when gathering speed but not on the way down.
Can it do any damage? I manually change out of overdrive if going up any steady climbs but it seems to do it on small rises as well when the revs drop off to 1500 or so. I just don't want to damage the engine.

Cheers
Amber

[James W]

It shouldn't be pinking, reguardless of auto or manual or reguarless of load... well in my definiation of pinking.

Possibles are;

1) some petrol in the tank.... Don't trust people at the petrol station, plus I manged to put a couple litres of petrol in once, early one morning when soemone swap the nozzles over on the pump.

2) Timming out - worn timming belt, worn timming idler puller/bearing, or maybe slipped a tooth.

3)A bad temperature sensor. The cold start system effects the timming slightly - making it diesel knock more, well on the 4JB1... I don't know for the 3.1L. Assuming you haven't got it turned on and it's not cold enough.

[geeves]

I would be getting an expert to have a look. Cheap insurance. It might be a small leak in an exhaust manifold but may be somthing serious like above or worse

[adrian]

Mine started 'pinking' or missing/ missfiring recently as well, not sure if mine is air getting into the fuel system though somehow??
ran fine on the first half the tank of fuel that is in, so i'm thinking it is ok to rule out fuel quality?
ade

[geeves]

If its the e,lectronicaly controled engine a worn governer can cause this followed by very bad things