I was changing my cousin's '97 Grand Cherokee AT filter when I noticed Motor Oil leaking from between the block and the head. It doesn't run like it has a blown gasket. Could it be blown anyway, just not from the piston? Could tightening down the heads solve the problem. I haven't seen this before so I really don't know what to think about it.

 

I would clean the area and add engine dye and drive it for a few miles and recheck it with a black light.

 

Here are some reasons for the engine oil leaking. you can check them to your drive.

1. due to loose bolts
2. due to worn out valve cover gaskets.
3. leak attributed to a shabbily fixed oil filter.
4. due to the gap brought on by worn out seal.
5. Damaged oil pan, due to bumping onto raised ground or running over a rock.

 

Are you certain that it's coming from between the head and the block or could it be coming from the valve cover gasket and spreading along the gasket line between the head and block - the valve cover is notorious for leaking. I would follow Master Tech's advise to make sure of where it's really coming from.

If the head gasket is leaking oil (not really common), I wouldn't advise just trying to tighten the head bolts. To get to the head bolts, you need to remove almost as much to loosen & re-torque them as it would to actually replace the gasket. The major difference between the 2 procedures would be that to change the gasket, you need to remove the fuel & exhaust systems from the head. Whatever you choose to do, remember to drain the coolant otherwise you're likely to get that into the oil when everything loosens up. Also remember that the head bolts are meant for only 1 re-use, then you need new bolts - this is why I didn't recommend just tightening the bolts unless you already know that the bolts are new or original & never removed. If you don't know the engine, it's not hard to snap a bolt or stud when trying to tighten a bolt that's been sitting in one position for a long time. One of the front corner head bolts (I think it's the driver's side front) goes into the water jacket and needs a lesser torque than the rest - this one is easier to strip.

 

Well if you still coping up the problem of oil leakage after using these methods then you quickly take your jeep to maintenance center. I am sure there your problem will get solved.