my new 94 940 na 130,000 miles has a very slight pinging after a couple of miles and at high rpm under load. A couple of cans of additives, the water in the intake trick and running high test has helped some. The compression test is 182-185 cold. While the car runs great, lots of power, the noise is slight and intermediate and worrisome because it has that sound of an engine running hot but the temp gauge is dead centered) Dumping out of OD makes it go away too. the frequency sounds like just one cylinder is the culprit/

I haven't pulled the valve cover,so the question: can an out of adjustment lifter cause this temperature dependent pinging noise? It doesn't have that click click click like a sticky lifter