Oil Leak at top of engine
 

My wife told me this morning that when she got home last night she could smell something funny when she got out of the truck. Smelled like someone was taring their roof. Well it's cold out, and neighbours have there woodstoves on so I just wrote it of as the smell of creosote from burning damp wood.

Not so perhaps, I checked the truck today, no oil or coolant leaks on the ground; however after opening the hood I could see oil on the intake manifold at the front of the engine by where the thermostat housing sits. Definately engine oil, I had just changed it a week ago and the oil laying on the manifold was clean. Further investigation reveales that the passenger side was completely oil free and dry, only the drivers side was wet. The oil was actually sitting in pools on the manifold but only in the forward half not the back half. It was dry. My first thought was valve cover gasket, but I need some reassurance here that this is not the start of the dreaded intake manifold leak. I am leaving for Christmas with the kids in two days, so won't be able to fix it for two weeks. But I can spend a while determining exactly where it is coming from.
Any and all suggestions gratefully accepted.

I would suspect the rocker arm cover gasket first. Could also be from the left front corner of the lower intake manifold where it meets the block. Not going to be easy to see as the AC compressor is right there, in the way. A long shot would be oil seeping up past the front intake manifold bolts. The torque on those bolts is very low and if thread sealer is not applied to the bolts, they can walk out and leak oil. The bolt holes go straight through to the valley, which has oil splash everywhere. Might have to clean it all off and then watch it closely for the source of the leak.

I have washed it down with brake clean and blown it off with air, ran it for 20 min, with no leaks. will do it again tomorrow,

Ran it for 20 min this morning--- no leak
Went to town today, 50 kilometer round trip--- no leak
The manifold was dry.
About to put 500 kilometers on it, so for now, I'll just let it develop, and moniter it.

Well after having put over 800 kilometers on it, the oil leak, finally reared its ugly head. The oil appeared in a bolt recess at the front left corner of the intake manifold. So it is either a porous manifold:icon_rolleyes: or a loose bolt. I am betting on a loose bolt. So tomorrow I am removing the offending bolt, and installing thread sealer on it before reinstalling it. Thank you Captain Hook-- may the crock "tick tock " never find you:icon_flowers:

;) thanks. Probably be a good idea to use a tap and die on the threads of the bolt, and in the head. Then give it a shot of carb cleaner to clean it out, not alot cuz it will go into the valley. Then apply thread sealer to the bolt and slowly torque to 132 INCH pounds.

Will do.

Might be your valve cover gasket getting weak.

That was the leak, no more oil formation at all.

Which was leaking, the rocker arm cover gasket, or the intake manifold bolt?