rattling timing chain? L18

[zed]

My rebuilt high-compression L18 is going well - cruises easily at 120km/h with a trailer!(75mph) But I think my timing chain is rattling on start up. Datzenmike warned that this might be a problem from skimming the block and head .020" each. Questions: what is the timing chain hitting? the valve cover? so the chain is lifting off the cam sprocket teeth? Other than shimming the cam towers, is there any way to fix this? At 2500rpm the oil pressure is 4.5 bar - I would think this would push the chain tensioner shoe harder against the chain to take up the slack...

[banzai510(hainz)]

timming chain?

Make sure the water thermostate housing bolts. or really the long one isnt pushing the tight side guide into the chain. Sometimes the bolt somebody gets a longer one and it pushes the guide IN and it catches on top as the chain comes down.

 

The lower part on the block is the OILER on the right side of the lower sprocket. Sometimes a loose chain will hit this and tear it up. Its possible to look down and see if its chewed up.

 

next is the slack side guide a bolt broke loose and cause the slack side guide to wiggle around.

 

pop valve cover and ck all this out if possible.Really soon as possible.

[datzenmike]

4.5 bar is about 65PSI ... good oil pressure.

 

Has the oil and filter been changed? Some 720 owners say that when the chain rattles their truck is telling them it's time to change the oil.

[hang_510]

when my oiler was worn through, it rattled on start up but once had sufficient oil pressure it stopped.

chain had some slap against the inside of the head = grooves.

 

 

... when the chain rattles their truck is telling them it's time to change the oil.

:lol: mine means its a qt low...

[zed]

The oil and filter are about 50 miles old - I changed oil and filter after 400km/250miles of running the new engine in. There were no metal chips or other debris in the oil I drained...

I will get the valve cover off, and check down the timing chain.

thanks for the advice