Hi. Yes it was skimmed every time. I suspect , as I have said, first the EGR Blocking - and if not the culprit, then I blame maybe an interior headgasket used ..?The problem with diesel EGRs is that they introduce exhaust he's into the intake.
Over a long period of time the soot in the exhaust gas builds up in the valve and the intake manifold. Where legal, blanking the EGR is a good thing because it prevents this.
That is the only issue, it shouldn't have any effect on the head gasket.
Was the head skimmed?
Sorry, I didn't read your initial post carefully....inferior headgasket...
Done the egr by passs on my D22 a few years ago have never had any cooling system issues after it was done, Might be better fitting a genuine nissan head gasket, Proper procedure when replacing head gasket is a head skim and cylinder head pressure test before the cylinder head is refitted it’s also important to make sure the block face is cleaned up properly, If it’s an ongoing problem there is certain sealants you can smear on the new head gasket before refitting the Cyl, head. Also remember to replace the Cyl, head stretch bolts.Sorry, I didn't read your initial post carefully.
Blocking the EGR will increase the combustion temperatures, no doubt about that.
So could those increased temperatures cause head gasket failure?
In theory, it would increase the risk. In practice you could be on to something.
I replaced a head gasket on a 2.5, but can't remember if I had blanked the EGR before or after.
When I done mines I fitted a catch can at the same time now the engine oil is always spotless between services, Don’t see why an egr bypass would effect the head gasket in any way ?.Blanked my D22 15 years ago, took off the radiator fan at the same time, it never needs topping up with water, and the blanking has never been a problem.
Keeps the oil cleaner for a lot longer, it used to be so very disheartening to do an oil change, dip it to check the oil level, and it immediately looked like it had never been changed!
As you have had the head skimmed every time I would be checking the block for a flat deck?