Knock Knock

[pulsarboby]

BOUGHT A GTIR OTHER DAY WHICH HAD A KNOCKING NOISE SOUNDED LIKE A CAMSHAFT! TOOK HEAD OFF AND REPLACED WITH A GOOD SPARE HEAD I HAD, BUT WHEN I STARTED IT UP KNOCKING WAS STILL THERE:evil:
BLOKE I BOUGHT CAR FROM HAD SPENT 6 MONTHS REBUILDING ENGINE, NEW FORGE PISTONS AND A FEW OTHER BITS ETC BUT HE SAID ONE OF THE PISTONS WAS A BIT TIGHT WHEN HE FITTED IT TO ROD!
WOULD A SMALL END KNOCK SOUND LIKE A CAM KNOCK? HE SEEMED TO THINK IT WAS A BIG END WHICH I HAVENT CHECKED YET!
CAR IS ALSO OILING ON NO2 PLUG BUT COMPRESSIONS ARE ALL GOOD AND EQUAL. ANY IDEAS CHAPS? THANKS

 

[Fazz]

Bottom end? or maybe cracked piston??? happened mine and similar knock noise maybe..

The Bore has to be perfect and per instructions so could easily be the problem if the guy said it was bit tight??

Change oil - will be able to tell if anything has found its way down to the sump!

 

[pulsarboby]

cheers matey will check next week

 

[crackerjack]

ive heard of people finding their rebuilt engines have had the pistons installed around the wrong way (not upside down!!) which would mean the oil wouldnt get through the galleries etc....

 

[stumo]

small ends usually have a much lighter knock than a bottom end knock.

They often have a rattling sound rather than a solid knock sound and quite often occur on a trailing throttle (ie when you come off the throttle) often occuring at certain RPM's.

 

[pulsarboby]

thanks guys, have checked pistons in bores and they are definately in the right way round, and there are no marks or anything on bore walls!
could it possibly be that the shims have been put back wrong? grooved shims are sitting on right hand valves as you look at engine from front. knock is like a heavy camshaft knock but isnt cams, it mainly knocks under load ie when you rev engine and gets worse as engine gets hotter