Injectors

[Agent_Orange]

Hi,
What do dodgy injectors sound like? Hunted around on FAQ and can't find anything.
Engine sounding a bit noisy lately (diesel-ish!) and get a strange groan noise when I back off and revs pass down thro 3k rpm. No not me groaning, from the engine! Got no timescales, can't remember when noise started.
Got a new down pipe last month - garage told me it could be resonating?..
:err:
Neil

[Predator_R32]

is it running ok, not misfiring??

[Agent_Orange]

Running a bit odd perhaps. It seems like one of those things that's creeped up on me almost. Maybe struggling a bit at tick-over. Justs sounding loud and maybe a bit rough to me. 87k and regularly serviced.

[Predator_R32]

could be worth a compression test or get it on the diagnostics mate

[devilsadvocate]

As pred said it could be missing, hence the diesel-ish sound. Take it to a garage and they will be able to tell instantly if it is missfiring. Again as pred said you will need a compression test to be 100% sure.

If it is missfiring it could be many things:

injectors
Coil pack
sparkies
head gasket
valves

could go on forever :/

[Tobs]

missfiring has so many different anwsers it could be (just let you know that :P)

just try dianos the fault

[Agent_Orange]

Also done a v.v.v.v.strange thing (that 1st few times I convinced myself it was me touching throttle by accident, but now know for sure it isn't!!), the Engine when cold is somehow blipping throttle and revving engine like some sort of poltergeist! Does it randomly even when driving or stationary?! Only up to 2k rpm ish...

[Agent_Orange]

Oh Aye,
And New coil pack, alternator, sparkies in not so distant past...
Hmmmm

[KamRacing]

when you say dodgy injectors there are only 2 main things that go wrong with them which is not opening and closing.. and not flowing due to a partial or full blockage

you can do the screw driver trick to listen to the injector and hear whether it opens and closes...

for blockages you need to check the flow