Jump to content

big ends and mains


Recommended Posts

hello boyz n girls,i own a p38 with 118.000 on clock n reg auto 4.6 petrol,the time has come to change the big ends and mains as i have knocking on acceleration.now i know you are supposed to take the front off to get at the bolt by the oil filter to release the crankcase holder(dont know what they called).is there any short cut to get bolt out.i havent got time to play to much as i need car back on road asap.also the tourqe settings for conrod bolts and crank would be helpfull.i have them for a 3.9 but not certain they are the same for 4.6.the oil i intend to use is 15/40 semi synthetic,is this any good.thanks for replys. ps it only knocks on acceleration from 500-800 rpm,i suppose its more like a rumble than a knock.

Link to comment
Share on other sites

Are you sure that it's the big ends? Could be a hydraulic valve lifter? Where does the sound come from?

soundd from the bottom half of engine,pretty certain its the ends.you can hear it on tickover and also when you pull away,but increase the revs to 800 the noise dissappears.i changed the main shells about 4 months ago but didnt do the front one by the oil filter.also didnt change the conrod shells,(was told there was no need)so im doing the works this time.

Link to comment
Share on other sites

If you fit new shells to a journal that worn with ovality (almost certain) then your wasting £s as they will rewear at an alarming rate

at best a short term fix, more likely a bodge. Additionally, as others have said Mains / Big ends don';t tend to go quiet as RPMs increase,

worth investaigating further


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy