Discussion
Noticed a new noise on my 'new' Griff 500 tonight, these are the symptoms:
On idle or neutral throttle at any revs is sounds fine
On anything more than about 10 - 20% acceleration I have a light fast tapping noise
This noise sounds exactly like my badly timed 1.6 Capri used to make (in my yuff!) - I think the garage said it was 'Pinking'.
I have checked the section of pipe from airflow meter to plenum - no holes etc. Thought this may have been the cause of the an AFR issue
So, does this sound like detonation? If so is it just a case of poor timing? If so which way and how much should I twist the distributor cap to retard timing? It's going to Austec in a couple of weeks but want a to protect engine in the meantime.
Car always run on 98+ fuel.
Thanks all,
Rob
Updated to add that there is also a barely audible noise like the sound created when blowing over the top of a bottle - does this sound more like a vacuum advance pipe leak? Best check this tomorrow.
On idle or neutral throttle at any revs is sounds fine
On anything more than about 10 - 20% acceleration I have a light fast tapping noise
This noise sounds exactly like my badly timed 1.6 Capri used to make (in my yuff!) - I think the garage said it was 'Pinking'.
I have checked the section of pipe from airflow meter to plenum - no holes etc. Thought this may have been the cause of the an AFR issue
So, does this sound like detonation? If so is it just a case of poor timing? If so which way and how much should I twist the distributor cap to retard timing? It's going to Austec in a couple of weeks but want a to protect engine in the meantime.
Car always run on 98+ fuel.
Thanks all,
Rob
Updated to add that there is also a barely audible noise like the sound created when blowing over the top of a bottle - does this sound more like a vacuum advance pipe leak? Best check this tomorrow.
Edited by rjben on Tuesday 22 May 22:34
rjben said:
On anything more than about 10 - 20% acceleration I have a light fast tapping noise
Perhaps it's a porker tapping on yer window wanting to know why your car looks and performs so much better than his. Just floor it, he won't keep up!
(Sorry rjben,... but it seems to be a pork ribbing night tonight. hope you get sorted!)
Al
Look for an air leak on any of the hoses around or connected to the plenum., If air is getting into the engine here it won't have been metered by the air flow meter so your engine will run lean due to the extra air and pink or even detonate. Also check the small hose behind the plenum for the fuel pressure regulator in case it's come off.
Boosted.
Boosted.
rjben said:
Updated to add that there is also a barely audible noise like the sound created when blowing over the top of a bottle - does this sound more like a vacuum advance pipe leak? Best check this tomorrow.
If it's only audible at idle it might just be the air flowing through the throttle bypass - adjuster screw, stepper etc. The tapping is probably manifolds blowing, especially if audible when the engine is not under load (although, like detonation you might well only hear the manifolds blowing under load). It's easier to check the timing than tighten the manifold bolts, so I'd do that first. It's also safer!
Nice one gents,
All good things for me to try there tonight.
I was under the impression the an exhaust manifold gasket failure would give more of a regular tapping noise - where this noise really does sound rapid and erratic, just like pinking I have heard on a car before.
Has anybody had experience of both pinking and gasket failure? Are they indistinguishable?
Cheers,
Rob
PS - Where has the recieve email on reply checkbox gone?
All good things for me to try there tonight.
I was under the impression the an exhaust manifold gasket failure would give more of a regular tapping noise - where this noise really does sound rapid and erratic, just like pinking I have heard on a car before.
Has anybody had experience of both pinking and gasket failure? Are they indistinguishable?
Cheers,
Rob
PS - Where has the recieve email on reply checkbox gone?
griffter said:
rjben said:
Updated to add that there is also a barely audible noise like the sound created when blowing over the top of a bottle - does this sound more like a vacuum advance pipe leak? Best check this tomorrow.
If it's only audible at idle it might just be the air flowing through the throttle bypass - adjuster screw, stepper etc. The tapping is probably manifolds blowing, especially if audible when the engine is not under load (although, like detonation you might well only hear the manifolds blowing under load). It's easier to check the timing than tighten the manifold bolts, so I'd do that first. It's also safer!
OK - Update
Had a good nose around last night and could spot no mising or split hoses BUT did notice that the vacuum advance mechanism on the side of the distributor was loose to the point of almost falling off. Tightened this up but still no difference.
I had a look at the exhaust manifold bolts but they are quite badly rusted. Knowing my luck any tightening will result a broken nut.
I guess I'll leave it to the experts at Austec.
Cheers for all the help,
Rob
Had a good nose around last night and could spot no mising or split hoses BUT did notice that the vacuum advance mechanism on the side of the distributor was loose to the point of almost falling off. Tightened this up but still no difference.
I had a look at the exhaust manifold bolts but they are quite badly rusted. Knowing my luck any tightening will result a broken nut.
I guess I'll leave it to the experts at Austec.
Cheers for all the help,
Rob
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