I have a 97 ranger 4.0L that takes 10w-30 and I'm going to be changing the oil soon. It has some valve clatter I'm just wondering if I can use a thicker oil such as 15w-30 or maybe a 10w40?
10W40 works fine. That's all I've ever run in my Explorer - and presently it has just under 200,000 miles.
I wouldn't go any thicker than 10w-40. I have seen 20w-50 in the parts stores, but this will put a lot of strain on the oil pump. You may regret it down the road, and it's just a little bit of noise. Good luck.
Valves don't clatter. Sticking or collapsed hydraulic valve lifter do. The use of the normal viscosity 5W-30 full synthetic oil contains a heavy dose of detergents. If gum, varnish or sludge is an issue, repeated use it may quiet things down. This is the least expensive thing to try first. If that doesn't do the trick it's time to (easily) replace the sticking hydraulic valve lifters. Thicker molasses oil may insulate noise while it's cold and heavy but it will never fix the issue.
