Engine rattle on down rev

[Dylan kingswood]

Last 308 I done had a light rattle down low and didn’t feel right but come in at 220kwatw pulled rockers and found either inlet or exhaust was just partially staying open got shims and only gained a few extra kw but sounded 10x better

 

[Dylan kingswood]

I’m only a bush mechanic but once valve is closed should have a minimal amount of play on rocker if tight I suspect it may need shims

 

[losh1971]

Last 308 I done had a light rattle down low and didn’t feel right but come in at 220kwatw pulled rockers and found either inlet or exhaust was just partially staying open got shims and only gained a few extra kw but sounded 10x better

[/QUOTE]Did it cause a miss and or high idle? Mine runs sweet. Could a partially open valve cause a high idle? I will add the revs sometimes go up on their own and also it starts out revving quite high when you first start it.
It's almost like I have a vac leak but I can't see anything off.

 

[losh1971]

I’m only a bush mechanic but once valve is closed should have a minimal amount of play on rocker if tight I suspect it may need shims

No mention of shims in the instructions and the stock rockers had no shims. Instructions were quite vague, the photos no longer work. I would have liked some photos or a more in depth instructions. Maybe they do need shims.

 

[losh1971]

Just checked and rockers have no free play. I have no clue what to do now. I mixed all the old rockers up as well as the rods not thinking i might need to put them back on.

 

[EYY]

Need to make sure there’s a little preload on every lifter. When you say noisy, is it a slight constant tick from all cylinders? Or very loud and pronounced?

 

[losh1971]

Need to make sure there’s a little preload on every lifter. When you say noisy, is it a slight constant tick from all cylinders? Or very loud and pronounced?

Its a rattle not a tic. You can tell its not supposed to sound like it.

 

[losh1971]

It sounds like a shot bearing or timing chain rattle.

 

[losh1971]

Give it some revs and the noise go away.

 

[losh1971]

Just to add it was quiet on start up just now but now that it's warming up the noise is appearing.