99 Ranger 4.0 OHV losing power/ticking loudly

[nthn135]

This post requires a little history:

I dropped a 4.0 OHV from a 2000 Explorer into a 99' Ranger recently. The engine has 150,000 miles on it, but was tested and checked before I purchased. Everything went well - it starts right up, and runs great for about 5 minutes. Once the engine reaches is normal operating temperature a few things start to happen:

-The engine starts to tick/click loudly when accelerating at mid-high RPMs.

-Along with the tick/click the engine begins to drastically lose power. To the point where I have to really limp it home while keeping its RPMs real low.

I've already changed the spark plugs (Bosch platinum double tipped) and the truck has oil pressure. The gas has been sitting in the tank for about 5 months, maybe its gone bad? I still need to change the fuel filter as well. But I don't think either of these is causing the issue I'm having. There is also a slight oil leak in the valve cover gaskets - not sure if it could be related.

Does anyone have any thoughts on this? Any input would be greatly appreciated.

-Nathan

 

[srteach]

You need to compression test when warmed up. I tend to think the tick / click is a leak past a gasket.

 

[nthn135]

How would I go about doing that? I'm assuming that is something I would have to take to a mechanic for.

So it sounds like an issue with compression then?