Educated guess why its started to sound like a clockwork orange...?

Oneball

Member
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11,075
Isnt it too metronomic to be anything but revolution derived..?
Mind you, it is too low now it's settled on its new legs, and I have to be careful of cats eyes that I dont wipe out the sump/cats/roll bar and such ! :oops: It has made 'earthly contact' down there, so its not beyond conceivable. In what sense would a manifold make that rhythmic, engine speed related noise, Tim ?

If there’s a crack in one or two of the branches you get a rhythmic sound that’s very similar to tappets and changes with engine speed. If you think about it they’ll just be one or two pops every two revolutions.

Has the 4200 got double skinned sheet steel manifolds?

If so the you won’t be able to see evidence of a crack as it’s usually the inner that goes and the crack closes up when hot hence only happening at start up
 

TimR

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2,656
If there’s a crack in one or two of the branches you get a rhythmic sound that’s very similar to tappets and changes with engine speed. If you think about it they’ll just be one or two pops every two revolutions.

Has the 4200 got double skinned sheet steel manifolds?

If so the you won’t be able to see evidence of a crack as it’s usually the inner that goes and the crack closes up when hot hence only happening at start up
Oh...bu55er. ( in a fast show stylee !)
 

TimR

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2,656
Of course, this might mean I ‘ll have to swap out the system for the earlier, euro spec headers....!
 

lifes2short

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5,821
Get one of these and track down where is coming from


second that, got those and bloomin good for that sort of thing and for stiring the coffee when you cant find the bar stard spoon
 

TimR

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2,656
I'm sure I can find 101 places to shove it. Stirring my coffee, I have Jeeves for that !

Seriously though...its an elusive demon. Sweet as a sewing machine after a night on the drive and cold start this AM..12 miles down the road and still not ticking warm. Passed its MOT; I hear it ticking as they emissions test it. Then ticking as I make the journey home only to find it purring like a sewing machine when I pull up on the drive again.

Its twisting my melon man...
second that, got those and bloomin good for that sort of thing ....
Ordered.....but its a bit like the blind leading the blind with me ! :whistle:
 

Scaf

Member
Messages
6,512
Duly ordered so I can drive myself nuts, seeings as how the old screwdriver in the ear hasnt revealed anything...! :D
I warn you they are very effective so
I'm sure I can find 101 places to shove it. Stirring my coffee, I have Jeeves for that !

Seriously though...its an elusive demon. Sweet as a sewing machine after a night on the drive and cold start this AM..12 miles down the road and still not ticking warm. Passed its MOT; I hear it ticking as they emissions test it. Then ticking as I make the journey home only to find it purring like a sewing machine when I pull up on the drive again.

Its twisting my melon man...

Ordered.....but its a bit like the blind leading the blind with me ! :whistle:
Even if you won’t necessarily be able to identify what is causing the noise, I promise you will be able to identify where it’s coming from.
On my Mustang I had a noise which everyone said was from the top, end tappets or valves, it was a loose bottom pulley, easily found worth the stethoscope
 

TimR

Member
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2,656
I will carry the stethoscope in the car for a while, in the hope that the ticking repeats itself to the same degree as before.
Im the first to admit that it is probably a noisy injector. And that it so far, doesnt seem to be a consistent offender. It hasnt returned to the same degree as previously ,which is good, and a little annoying. Not complaining mind....
Pretty surprised an injector can get that noisy tbh. I wouldnt have thought it if it wasnt for comments on here...They should self lubricate, and cranking it over with the fuel pump relay disconnected may have had it's part to play here I guess. :)
 

TimR

Member
Messages
2,656
Thing is , I took all the injectors out about 5K miles ago, sent them away and had them cleaned and flow tested. Flushing gunk through combustion chambers past the valves etc; never really appealed to me as a solution somehow ! They were impessively within spec even after +50K miles. Not saying you're wrong but another 5K aint going to touch the sides really....?
I recently ran "cat cleaner" through a quarter tank of fuel. (Paranoid about emissions). This has started since but in truth, I need it to replicate the symptom. Until then, Im not worrying about it. Too much....:worried1:
 

philw696

Member
Messages
25,120
Interesting it ain't your injectors then.
The Cat cleaner you have put through has gone through them since so I wouldn't be putting anything else through other than premium fuel.
Having had a few of these engines apart over the last 10 years I have not seen one dirty internally ever.