vx knocking noise

[Simonn]

gday, picked up my vx s pac today I am wrapped 1st car. When we went to inspect it started great with no knocks or anything. Picked it up and it now has a loud knock or like a bang sorta sound when starting it also when turning it off in the last moments there are afew rattles. Also when realesing the clutch more so downshifting there is a few minor knocks/minor clunks that can be felt, It is obviously a manual with a genuine 108,000kms on it. Any help would be great. We are thinking its the flywheel that may be crook. The clutch got replaced afew months ago (recipts were provided) or maybe even the starter motor. But then it wouldent account for clonks when changing gears.
any help would be geat.

thanks

[fitz_vt]

from what you have described it sounds like the new clutch isnt activating properly or there is something wrong with your master cylinder weather it be clutch fluid or a few gears being a bit sticky, it could also be what is called Diff backlash. before i can give a definate answer can you tell me if
is it hard to put into gear?
have you checked your engine mounts?
is there any other sort of knocking noise?

[Simonn]

no its not hard to put into gear at all. The clutch fluid looks to be very dirty but its not low. Would the clutch fluid or master cylinder have anything to do with it becuase even if I start it in netural I get a noise. Same as diff lacklash it wont explain why it makes such a horrid noise when starting and turn the engine off in neutral. Ill check the mounts tomroow. But other than that no noises at all.
once again your help is appreciated

[fitz_vt]

well the characteristics you have explained sounds a little like the Engine mounts. or the clutch fluid but i doubt that it would be the clutch as they have to change the fluid when they change the clutch plates.

does this noise happen on Idle, and disappears when you accelerate and then when you decelerate it appears again?

[Simonn]

na not really the noise is only there when starting the engine, sometimes when changing gears and a small noise when turning the engine off. But na when moving unless I'm chnaging gears there is no noise at all

[fitz_vt]

intersting i am sure someone has an idea as i only have a few, but you never know i might find somthing in either the holden repair manual or the gregory's lol.
i'll keep you posted on anything i find.

[Simonn]

ok thanks for that, Could somebody please tell me the syptoms of a stuffed flywheel? and tell me if my problem could possibly be flywheel related.
thankyou

[fitz_vt]

Symptoms of a stuffed flywheel
Slipping clutch, clutch shudder, Clutch grab, Insufficient clutch release and bearing noise.
your problem may be flywheel related but this should of shown up when you had your clutch changed.
spoke to a ex-holden service tech today that recomended to look at the flywheel and check for scoring or cracking, if so renew the flywheel.

[Simonn]

think we may have found the problem. a worn belt tensioner pulley. Hope it is this and not the flywheel. ill keep you posted.

[fitz_vt]

hopefully for you its the belt tensioner pulley

[kart_racer]

I'm thinking flywheel. The rattling/clutch knocking etc. is exactly what my car is doing and we are sure it's the flywheel, replacement is on the way.

Do yourself a favour and get a reputable solid flywheel & heavy duty clutch and rid yourself of the troublesome factory gear.

[SSbeast]

Could be loose bolts from flywheel to crank and the sound is the fly wheel moving. Everytime u unload the weight it comes free then load it up it hits the bolts. Get a screw driver and see if there is any free play on the flywheel.

[fitz_vt]

Could be loose bolts from flywheel to crank and the sound is the fly wheel moving. Everytime u unload the weight it comes free then load it up it hits the bolts. Get a screw driver and see if there is any free play on the flywheel.

i would be care full but its a good suggestion along with the other suggestion to ditch the factory setup get a solid flywheel and heavy duty clutch, it will work much better but with apparently with the solid flywheel you may get what they call Harmonic Balancer Noise, its nothing to worry about but you need to keep an eye on your harmonic balancer (crankshaft pulley) its the big pulley at the bottom of the serpentine belt, it has a large rubber seal in it and two flywheels which makes sure that the engine, powersteering, water pump , air conditioning and alternator run in harmonic balance.

[kart_racer]

I'm thinking flywheel. The rattling/clutch knocking etc. is exactly what my car is doing and we are sure it's the flywheel, replacement is on the way.

Do yourself a favour and get a reputable solid flywheel & heavy duty clutch and rid yourself of the troublesome factory gear.

Well...I replaced my flywheel and I still have the rattling on shutdown. The opinion seems to be the car is 'dieseling', still kicking after the ignition is shut off which is a timing issue apparently.

It's amazing how many issues aren't noticed when the engine is mated to an auto, but rear their heads when a manual box is bolted up...

[fitz_vt]

Well...I replaced my flywheel and I still have the rattling on shutdown. The opinion seems to be the car is 'dieseling', still kicking after the ignition is shut off which is a timing issue apparently.

It's amazing how many issues aren't noticed when the engine is mated to an auto, but rear their heads when a manual box is bolted up...

Potential causes Of Dieseling

This condition can occur for a multitude of reasons:
Built-up carbon in the ignition chamber can glow red after the engine is off, providing a mechanism for sparking unburnt fuel. Such a thing can happen when the engine runs very rich, depositing unspent fuel and particles on the pistons and valves. Similarly, non-smooth metal regions within the piston chamber can cause this same problem, since they can glow red. It has also been suggested that an improperly rated spark plug can retain heat and cause the same problem.
A carburetor that does not close entirely can contribute to running once the engine is off, since the extra fuel and oxygen mixture can combust easily in the warm piston chamber. Similarly, hot vaporized oil gases from the engine crankcase can provide ample fuel for dieseling.
Incorrect timing.
An engine that runs too hot or too lean may produce an environment conducive to allowing unspent fuel to combust.
An idle speed that is too fast can leave the engine with too much angular momentum upon shutdown, raising the chances that the engine can turnover and combust more fuel and lock itself into a cycle of continuous running.

Thought this might help