Engine Trouble

I'll give truck and maintance details first so those questions don't have to be asked. I have a 2006 Tacoma Xrunner with the 4.0 V6 (89k miles) I run Mobile 1 High Mileage Synthetic oil with an AC-Delco oil filter. I always run 93 premium gas in the truck (due to engine ping if I don't) as of lately I've been smelling a burnt smell from the engine bay. It's not the "ricey" burn like a V6 Mustang trying to speed off down the highway burning up the engine. But possibly oil burning? I checked the oil and the levels are consistent from the last time it was changed (3k miles ago, change it every 4,500 miles) I have no idea what it may be but its only at speeds past 50 or if I don't shift gears before 2200 RPMs does anyone have any suggestions or a similar problem they have fixed? If it helps I can't smell the burn from the tail pipe if I pull over and get out but I can still smell it from the engine bay. Any help is greatly appreciated.

 

Looks like you may have a minor leak once the oil pressure goes up. Check your engine bay for signs of leaks, it may be a leak near the headers/ exhuast area. Check the oil pan seals and valve cover gasket areas is where I would start.

 

Oil pan seals are good, I checked those first (probably should've said that in the original post) I didn't think to check the valve covers. I have noticed oil trying to build up and sludge where the filter screws on. I wiped it clean last time I changed the oil and it's built back up. I figured it might be a Toyota thing that it leaks out at the filter? It's not much but I guess it could be enough when it flows out from the drain hole it would fall directly in the headers. Is it a common issue for the filter components to leak? This is my first Tacoma. Always driven older Chevy pickups so I'm having to learn everything new on this V6.

 

Your oil filter shouldn't leak, when you put on a new filter do you oil the o-ring to help give it a nicer seal, it also helps with removing the filter later when you do another oil change. Just a light film of oil on the rubber o-ring helps with sealing it.

It could be a possibility that the oring on the oil filter isn't sealing good enough. Perhaps you should change the oil filter with a new one to see if it'll leak there again.

 

I do put some oil on the o-ring learned that the hard way when I was 16 with my first truck. Got an oil filter over tightened and froze on my 93 Z71 I'm planning to change the oil tomorrow since it smells burnt when I check it. I'll go ahead and replace the oil filter and see if it still leaks from there. My only concern is ice been noticing it leaking from that point since I've owned this truck and never smelt the burn smell before.

 

I stole this picture off google, not mine but anyhow you see the oil cooler with the two hose adapters coming off it, well underneath it also should contain a gasket or oring that may be leaking. The nut and bolt looks like it's already been removed in this photo but basically there is a threaded hollow bolt that holds the oil cooler adapter to the housing then your oil filter screws on top of this housing using that threaded hollow bolt. Hard to explain but this area could leak too if this seal gets old and hard.

I do not know how this setup exactly works but on many other engines it's basically the same. I tried looking for diagrams but it doesn't show an oring in that area.

 

I'll check the whole assembly, thanks for you help!