"Ticking" noise on hard throttle

[bigtone0777]

I'm getting a "ticking" kind of noise when accelerating hard. The car has bags of power and runs a dream so nothing is obviously affected. The noise reminds me of a tappet but only happens on hard throttle. When cruising at the same speed/engine speed it's as quiet as a mouse. Could this be some kind of fuelling issue?

Forgot to mention it is an HDi with 133k, not sure if it's had the ECU "tampered" with before I got the car but been de-catted but other than this as far as I know it is totally stock.

Ta!

Tony

[Jimbo]

Does the noise stop at around 3200rpm?

[bigtone0777]

Hmm quite possibly, I'm driving it all night tonight so will take more notice

[rd070707]

Does the noise stop at ~3000rpm? If so its your injectors. Nothing much to worry about I've been told but you could replace them with a low mileage 076 set which might see some mpg gains and it gets rid of the noise lol

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If it doesn't could be looking at crank pulley or something

[bigtone0777]

I definitely thought something more to do with fuelling rather than a pulley/tensioner/idler as it's only ever on hard throttle. If it's just an annoyance and nothing too much to worry about I'll just put the radio on lol

[Jukie88]

injectors:-) mine did the same went away at 3200rpm odd replaced it with some scrappie injectors and it was fine for a while but noise has come back just not as bad lol it bugged the hell outta me even tho it wast really and issue might invest in some 307 ones at some point if there are are any gains from them

[Dum-Dum]

The 307 injectors are the same injectors, you wont see any gains apart from the fact they might be lower mileage and thus less worn.

Apparently just changing the copper injector washers might solve the problem.

[Jukie88]

Yeah I changed them when I changed the injectors as I was advised :-( ahh well just have to bare with it :-) not as loud as it was before so its bareable

[bigtone0777]

Does the noise stop at ~3000rpm? If so its your injectors.

Took notice tonight and it starts at about 1750 rpm and goes again at 3000 rpm. Seems common opinion that it's injectors so will leave alone until something fails or the noise gets unbearable.

[Dum-Dum]

Yeah you want to hear how loud mine are mate if your worried about yours. Mine are border line bad enough that I'd consider doing something about it.

[bigtone0777]

Yeah you want to hear how loud mine are mate if your worried about yours. Mine are border line bad enough that I'd consider doing something about it.

Nah not worried now I know what it is. I can safely say I won't be doing anything about it lol

[Gaz7]

It's not the injectors you're hearing, although they are the cause, you're hearing a diesel knock, a worn rod allows fuel to leak from the pressure chamber into the control chamber and hold the solenoid open for too long on the pre injection phase, meaning you end up with a larger injection of diesel than required.

[mcglynn]

It's not the injectors you're hearing, although they are the cause, you're hearing a diesel knock, a worn rod allows fuel to leak from the pressure chamber into the control chamber and hold the solenoid open for too long on the pre injection phase, meaning you end up with a larger injection of diesel than required.

so would it explain why mine is quite smokey on throttle in neutral (off load revving)?

in two minds whether or not to replace my injectors because of this...

[bigtone0777]

It's not the injectors you're hearing, although they are the cause, you're hearing a diesel knock, a worn rod allows fuel to leak from the pressure chamber into the control chamber and hold the solenoid open for too long on the pre injection phase, meaning you end up with a larger injection of diesel than required.

That's what I was worried about at first thinking it was a diesel knock from something to do with fuelling. Not sure what to think now........drive it until it stops!

[mcglynn]

I replaced the injectors for some 076 models, it now revs freer and pulls harder right through the range with no noises.

WIN! My 044 ones must have been well knackered, not doubtful with 138k on them

[Dum-Dum]

It's not the injectors you're hearing, although they are the cause, you're hearing a diesel knock, a worn rod allows fuel to leak from the pressure chamber into the control chamber and hold the solenoid open for too long on the pre injection phase, meaning you end up with a larger injection of diesel than required.

I don't think this is the case. I know what diesel knock sounds like from firing a) too much methanol and b) Pure butane down the inlet.

It also doesn't explain why every set of ticking ones I've seen has injector blow by and how replacing the washers underneath them apparently cures the ticking (and also the blow by).

[mcglynn]

Hmmm mine had blowby too, hopefully the 076 injectors are in fact better by design lol

[Dum-Dum]

Hmmm mine had blowby too, hopefully the 076 injectors are in fact better by design lol

They are the same injectors there is 4 other part numbers

[mcglynn]

So it was pointless me buying the 076 ones really?

[rd070707]

People only recommend them as it is easier to find a low mileage set based on the cars they came on

[mcglynn]

Hmm I never even asked for mileage, I based my purchase on the fact the 076 ones had updated internals.

[Poodle]

Allegedly the 076 injectors were made with finer tolerances, but i've yet to find any solid info to substantiate that.