Guest ae86clyde Posted January 10, 2008 Im quite a new 205 driver only had the car 6 months. I decided to do an Mi conversion, i bought the engine fitted it and after 30mins once it heated up i heard a constant knocking from the engine so straight away i thought big end bearings. So pulled of sump and sure enough big ends were scrap, i left crank in the car and fitted the new standard bearings as the crank appeared to be unmarked. All back together out on the road 30mins later same knocking noise again. So same process again with main bearings again crank seamed fine but after the 3rd test run still the same knocking. Ive since took the engine out and pulled the whole thing apart, i took the crank to get ground but the specialists i took it to said it was fine and only needed polished while charging me a small fortune in the process. So now ive got a freshly ground crank, a newly skimmed head and new standard sized main and big end bearings and thrust washers but i dont believe this will sort my knocking noise out. So my question is can anyone tell me what else my knocking noise could be other the bearings as i dont want to put the whole thing back together to come up with the exact same problem. There is no noticeable nosie when the engine is cold, on when it heats up so that leads me to believe it isnt piston slap as it would be more noticeable from cold and i dont think its tappets as it sounds like its coming from the bottom end. Sorry for such a long post but ive spent a fortune so far and im running out of ideas!!! Any thoughts or opinions would be greatly appreciated thanks. Share this post Link to post Share on other sites
nick 3 Posted January 10, 2008 Did you inspect the rods? if it has spun a shell at some point (which is almost inevitable on an Mi) which ever rod spun will be scrap. Nick Share this post Link to post Share on other sites
Guest ae86clyde Posted January 10, 2008 Did you inspect the rods? if it has spun a shell at some point (which is almost inevitable on an Mi) which ever rod spun will be scrap. Nick They seem fine but im going to see another pug specialist on saturday and ill let him have a look at them cos im not too sure how to check conrods? Share this post Link to post Share on other sites
Miles 331 1 Cars Posted January 10, 2008 Could be Rod's, Little end bushes, Piston Slap, Have you plasty Guaged the bearings when refitting? this will tell you what clearnace you have between the bearing and crank journel. Share this post Link to post Share on other sites
Guest ae86clyde Posted January 12, 2008 Conrods appear to be the issue, i will check the bearing clearances aswell once we go to refit but now im waiting on prices for competition pistons and liners and rods as liners are also quite worn. Share this post Link to post Share on other sites
Guest ep82chris Posted January 21, 2008 (edited) just to update this a bit i checked the bearing clearnaces tonite all about 2.5 -3 thou dose that sounds about rite ? rods all look fine too(crank was all so sent to be checked and polished all ok). liners are abit worn but nothing crazy Edited January 21, 2008 by ep82chris Share this post Link to post Share on other sites
nick 3 Posted January 21, 2008 Have you had the crank check to see if it's straight? If it has spun a shell before the cranks are know to bend slightly. Nick Share this post Link to post Share on other sites
Guest ep82chris Posted January 21, 2008 (edited) Have you had the crank check to see if it's straight? If it has spun a shell before the cranks are know to bend slightly. Nick crank seams grand mate it was check over and was said to be 100% it never spun a shell thay just looked worn more than any thing. the knock was at about 3k rpm when hot. hears a pix of the old big ends might help Edited January 21, 2008 by ep82chris Share this post Link to post Share on other sites
Miles 331 1 Cars Posted January 21, 2008 Next thing to check is the Cam's, I;ve known these to wear the end of the lobe and cause a odd sound at certain rev's, other than that it time to remove the pistons and check them Share this post Link to post Share on other sites
Guest ep82chris Posted January 21, 2008 should have said pistons are out seam ok tho new rings will be fitted along with new liners . also the cams look ok too . im runing out of ideas hear lol Share this post Link to post Share on other sites
