VVT-i Oil Control Valve

[06YarisRS]

I have some ticking under load from my 08. No ticking at idle. It's not really heavy but my 06's engine is pretty quiet so I see no reason that the 08 should not be the same. As I mentioned in an earlier post, when I bought the car it was low on oil and what oil was there was pretty black. This evening I pulled the OCV and was surprised to see how clean it was. I've done about 3 short oil change intervals so I think it's cleaned up any junk that may have been inside the engine. I ordered a valve cover gasket and plan to test my valve clearances. Hopefully they are within spec as valve bucket replacement appears to be a major job involving removing the camshafts. I used my stethoscope and didn't hear anything really bad from either the intake or exhaust sides but I don't have a trained ear. I'm going out a on a limb here and will predict - probably incorrectly - that I have a valve that exceeds the max spec of 0.25 mm for intake or 0.35 mm for exhaust. It sounds like a cam lobe whacking down on a bucket, but again, this is just based on reading I've done online and not from experience with any overhead cam engine. I did do valve adjustments using feeler gauges on older engines I had that were equipped with push rods and rocker arms.

Certainly open to other suggestions as to what might cause a seeming valve train noise under load. I'll inspect the exhaust manifold tomorrow to see if there are any leaks. Apparently, this can sound like a valve tick. The tick does subside somewhat after the engine is at operating temp for a while. I also reduced it a bit with a switch from conventional 5W30 (Castrol GTX) to SuperTech 5W20 Full Synthetic.

I will also drop the pan this upcoming week and check the condition of the oil pickup tube.

Here is a pic of the ocv. I expected to see some type of screen in there, but didn't.



Here is a pic from the last oil change. 14" winter wheels and tires were also installed with another set of cheap eBay hub caps. Fake 5 bolt covers, but, hey, they were cheap! While the car was up there, it got a thorough soaking of ProForm dripless undercoating including all frame rails, doors, engine bay, wheel houses, quarter panels, doors, hatch etc You can see the sprayer just to the right of the hoist post.