Mechanics

NISSAN NAVARA VALVES PROBLEM

2006 Nissan Navara • 30,000 miles

After removing the cylinder head re planning the head and re cutting the valve seats, re assembly and ready to start? Wont start valve timing is ok, no compression valves must be open++ question should we have removed same amount of the top of the valve stems as we dis when we re seat the valves? I have a nasty feeling the valves are open its a diesel turbo common rail motor 2006 hydrolic valves any ideas if this is the case can we set thiner shims on the lifters?
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Multipurposecampers
November 18, 2012.




You need to check the valve clearances and adjust when the valve seats were refaced. For the valve clearances, thinner shims would be required if there is insufficient clearance. You need to get the measurement of the original shims and clearances available, total them up and minus the required the valve clearances, that would be the shim thickness you need.
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KHLow2008
Nov 18, 2012.
Thanks for your help, is there shims available? As you say I should have checked the clearence straight away, its hydrolic valves, they must have taken a lot of the valv seats to make that mutch difference, do you have any idea what the clearence should be?


Tiny
Multipurposecampers
Nov 18, 2012.
Sorry I missed the part on Hydraulic Lift Adjusters (HLA ) because the ones I have worked on uses shims and you mentioned shims which got me off track.

HLA would be easier to handle. There are no shims and all you need to do is to relieve the pressure on the HLA.

There are no valve clearances specifications for HLA except that there must be some clearances when the cam lobe is not pushing against it.

Nissan uses HLA that is in the form of a cylinder and you need to take them out and cup it downwards repeatedly on a wooden block to take the piston out and clean them before reassembly by pushing the piston inwards fully, the would take the pressure out of the HLA.


KHLow2008
Nov 18, 2012.
Many thanks, as the cylinder head has been totaly stripped down there shouldnt be any pressure till you start the engine and get oil pressure, Tommorow I am going to lift the rocker cover and first check that there is clearence and then go from there, if there are no shims available then we will have to remove the head again and take of from the top of the valve stem to create clearence, the work shop should have done this automatically the same amount as they took from the valve seat to compensate, was hoping I dont have to lift the top again, ouch


Tiny
Multipurposecampers
Nov 18, 2012.
No, HLA do not self bleed. They would remain where they are when removed, unless you set the oil holes to drain the oil out.

If it is HLA, you don't need to machine the valve stem down unless releasing the pressure on them is insufficient to create clearance.


KHLow2008
Nov 18, 2012.
Ok thanks alot mondaaaay tommorow start with taking out the lifters and check for clearence, many thanks


Tiny
Multipurposecampers
Nov 18, 2012.
You're welcome.


KHLow2008
Nov 18, 2012.

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