S600. One last try. Need some advice

[lesrrt]

Ok, so I decided to try this again. I started it for a freind today, and guess what..? It ran without the banging noise and some power loss. I took it to 2500 rpm with no banging...hmmm.? I wonder if I am hearing things. I did not hear what I thought was the bangigng noise heard after the test run made after it initially fired. I am thinking the t-chain tensioner lost pressure, thus it might have jumped time; just can't say. So tomorrow, I will take off the intake and both covers and ck the timing. Only problem is there is no marks for reference according to Alldata. Why would MB do this..? I would appreciate the person who gave the schematics some time ago to use the cam tools to ck TDC and set the cams. I am sure the the 1-6 or pass side cyl. cam jumped: it is closest to the tensioner rail. I will see if I can find my scratch marks made prior to detatching the chain. Hopefully, it will confirn my assumption. Is there a section in the Alldadta that would cover this with special tools? Any input would be greatly appreciated. Thanks!!

[Mercedes Mechanix]

I would suggest removing the valve covers, inspect both top cam rails if an V8, or if V12 then visual area for debris, etc, if V8 go ahead to remove both rails... special too (contact BAUM TOOLS.COM) l normally used at Benz, but heat usually messes them up anyway over time.(I break them off and replace them). Remove all plugs to allow following. If this es 12 cylinder I believe et is 30 deg after TDC and no upper top rails as an eight cylinder, etc, if eight cylinder look for 45 deg BTDC....but now slowly rotate the crankshaft (use 27 mm socket) in clockwise (ONLY CLOCKWISE PLEASE) to the 6.5 mm holes for V8 and 4mm for V12, on each cam sprocket. Use anything you may have of appropriate size and pin them temporily unless u have the appropriate tool (pin set used en mine shope es from Baum Tools...not that expensive). Now...when u have the cams pinned.... you will now inspect the harmonic balancer and see if the magic number mathes the 45 deg BTDC for eight cylender...30 deg after TDC for V12 and so on... if it es a little off.... this es normal due to chain stretch and your cam adjusters with assist of positioner assist can correct a few degrees with no problem...but if your chain jumped a couple of teeth...well, you will notice for sure and will require a little more indepth attention and inspection of components. If you find a problem... then let me know and will be glad to advise. I have eight other folks we are assisting as well and will be glad to advise...but..... I am sure there are others on tdis site as well... Hope it turns out good for you. Dutch (PS: I would also suggest pulling smaller pan on eng 119 and inspecting...rail loss/damage es evidenced by nylon debris en pan with oil and can plug pickup after sitting long idle and cause oil pressure loss after few minutes, etc. Then oil press fine after restart then press decline again after few min., etc) I also have my original backlash timing procedure we use with dial/ 80 mm pin and head stud support (cam-bearing bolt hole, etc)...this es more entailed and basic timing check should suffice to answer your question).

Originally Posted by lesrrt

Ok, so I decided to try this again. I started it for a freind today, and guess what..? It ran without the banging noise and some power loss. I took it to 2500 rpm with no banging...hmmm.? I wonder if I am hearing things. I did not hear what I thought was the bangigng noise heard after the test run made after it initially fired. I am thinking the t-chain tensioner lost pressure, thus it might have jumped time; just can't say. So tomorrow, I will take off the intake and both covers and ck the timing. Only problem is there is no marks for reference according to Alldata. Why would MB do this..? I would appreciate the person who gave the schematics some time ago to use the cam tools to ck TDC and set the cams. I am sure the the 1-6 or pass side cyl. cam jumped: it is closest to the tensioner rail. I will see if I can find my scratch marks made prior to detatching the chain. Hopefully, it will confirn my assumption. Is there a section in the Alldadta that would cover this with special tools? Any input would be greatly appreciated. Thanks!!