[scurr]

Just checking the valve clearance today among other things not expecting to have to do anything as most people state it doesn't normally need adjusting. Every thing was in spec except for one of the intake valves on number 4, but what I find strange is it's clearance has decreased! I would have thought it would only increase due to wear or this this pointing to another problem else where? See print out below! Any Ideas anyone.

Cheers

 

[peterowensbabs]

Petrol or diesel?
Build up on the valve seat - varnishing or debris. If diesel look for pitting on your glow plugs or worse still chipped off bits. maybe???

 

[scurr]

The engine is a ZD30. I would of thought that if there was build up on the valve seats the clearance would increase? If no how?

Cheers

 

[scurr]

Bump

 

[giorgel]

my ZD30, 160 k, is quite opposite
from no.1 to no.4, valve clearance increased, from 0,4 up to 0,5 mm.

wiil like to adjust, but is a bloody operation: measure clearance, extract shims, measure them, calculate de right thickness, ORDER new shims, wait for them to come, install them....

if something goes wrong, another waiting...

none of nissan dealers have the case with the adjusting shims....

how many k is yours?

 

[hellfire_bitchslap]

valve recession into the head causes the reduced clearance. it can receed so bad in severe cases that you end up with no valve clearance and the valve will stay slightly open and cause you even more problems. extreemly rare in a zd30 aparently though

 

[gtst25]

valve seat wear. Probably been set like that since new though.