Mechanical rythmic tapping.

[ADENUF]

G'Day all and happy new year..
i managed to find the time to get up under the dash with a length of hose as Mudrunner sugested but failed to locate the culprit.
I took it back to the mechanic but got the same dont know what it is but i can spend hours looking for it if you want??frustration sets in....
this week i discided to put some injector wash in my petrol tank as i havent dont that for a long time(i dont normaly use petrol,i know i should for the lubrication benifits)
so i poured the wash in, filled up with petrol,pushed the subtank button on the dash to switch to petrol and what do you know,the noise stopped the second i press that button.
so i drove around for 30 mins switching from petrol to gas and sure enough the gas seems to be the issue,theres no discernable diference between gas and petrol except a small increase in power on petrol,the only thing diferent is the tapping noise.
So,now iv'e narrowed it down to the gas system somewhere under the dash ill take it back to the gas guys that did the service and ask them a few questions.
Ill keep you all informed as to what happens.
Steve.

[ADENUF]

G'Day all.
Finally had the time to go back to the Gas guys that did the service a couple months ago,was expecting the run around as usual,not an instant fix with a cable tie
Here's what happened.
When i booked it in originally for the Gas service I was asked what i wanted done,I said what ever needs fixing or replacing as I'm off to Queensland in a couple months and don't want a hassle.
So they changed all the filters,plugs,leeds,a couple of hoses adjusted tappets and changed the fuel processor.
I pull into their drive and the mechanic comes over,jumps in the cab,listens and says yer there's a noise.goes over to his boss and he says "that's the fuel processor"i said didn't you change that,he said yep.
when they changed the fuel processor they relocated it onto the heater hoses.which i pointed out to the guy that took my money and he said "no we didnt move it"which i know they did as it was closer to the firewall.
What was happening was that the body of the processor was in contact with the heater hose and the tick tick tick from the processor was being transmitted through the hose into the cabin and amplified in the heater making it sound like a donk donk donk noise.
(If you have gas, pinch the body of the fuel processor and you can feel the ticking it makes)
so he grabbed a cable tie ,moved the body of the processor away from the hose and Instant fix lol
So im happy as larry now,didn't have to do exploratory surgery as i was advised,no new expensive parts that i didn't need and no frustrating noise...Finally
thanks every one for your advise
And it just goes to show even the most annoying things can be fixed with a cable tie
Steve.

[threedogs]

Cheap fix, good result, some mechanics are shonky , at least he supplied cable tie I hope

[TurboOne]

I think they would of been more embaressed they forgot to put it in.