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Discussion Starter · #1 ·
Hi guys i have a new problem and they just seem to be coming in the loads.\
here goes i have a issue or so i think at least i think it is.
I have a standard nur sep motor fitted brand new and just finished running in with a mono grade oil 1200 kms changed twice during that time.
Now i was testing my flywheel for another problem and i was revving the car in the engine bay when i heard a weird noise between 2000rpm and 4000 rpm roughly.
The noise isnt a knock not bottom end cause it a very fast grrrrrr type noise systematic with the cams .
So under acceleration i hear the noise it sounds like a top end problem and high pitched not low like a bearing knock.
I have a ati damper and a flywheel that unbalanced at high revs.
can dual mass flywheels make a grrrr noise under acceleration and then noise goes away once a you stop accel and keep constant rpm??
it doesnt happen under de accel
So it might be the dual mass flywheel resonating cause its fried?
or should i be looking else where.
oil pressure at 4 k rpm is 6 bar
and rises higher with higher rpm
Oil changed and is now a synthetic 10w-60 castrol edge
Can a cooked flywheel make this noise like a fast tak tak tak so when reving the engine sounds graaaakkkkk and then noise goes away??
under load the noise isnt there is this clearances .
I havent stripped this motor i just installed .
Ps i also have a hard time with cold starts have to put my foot on throttle slightly is this correct ?
then after third crank she fires hestantly
changed fuel filter as well now sure of fuel pressure though.
 

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sounds like mine did when big end bearings were on the way out.......

mine also sounded like it was coming from elsewhere but it was the big end

sounded like "tappets" in a old ford but quieter but only under load as you described
 

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Discussion Starter · #3 ·
Thank you for the reply what would cause this

If my flywheel was unbalanced would this cause the big ends to fail ?
i knew something like this was going to happen i just had a feeling.
Lucky i have a few spares but now an engine rebuild on a brand new engine imagine only dont 1000kms on it and shortly after the run in i detected a problem with the clutch because of the vibrations when reving over 5000rpm .
I took it easy running it in and never reved past 5k
Now that its run in i took it up once or twice and felt this weird vibrations coming from the whole car ....
So i left it and didnt rev any higher ive been driving plus or minus 200kms more after the first 1000kms ive done.
Should i unsettle the rings and rebuild from scratch or just do the crank big ends and mains ?

Kind regards
Adam
 

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try recording the noise and posting it? not sure how that would help over the exhaust/background noises? but worth a shot I guess.
 

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at 3k revs is where mine had a strange noise. im a mechanic by trade and i didnt put it down to big end noise at all but it was in the end.

i hope thats not the case for you though mate. i had knock readings consistently over 100 up in the revs aswell on pfc.
 

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Discussion Starter · #7 ·
Guess what :( it was my main bearings and the Mains and bigs have failed will post pics up on my other thread and hear what people have to say about it.
So its back to the drawing board for me.
thanks for that peice of advise though
 
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