Ok so i have a 2000 block with the 0331 head and it is original. Mileage unknown. However after a compression test all cylinders are 150-160psi. The reason I’m posting this is I am losing a little bit of coolant that seems like a slow leak. There is absolutely no signs of coolant in my oil or vice versa. I lose an inch or 2 of coolant from the resivor every couple weeks. And I do get somewhat of a little miss at idle but it’s very light. I pressure tested the coolant system and found very small leak by the t-stat hose. I tightened it up and it went away. However, after the pressure test I started the jeep up and it seemed to idle a little more rough and the exhaust smelled different and had more steam and then returned to normal. (take note that it’s cold out). This makes me think the pressure test pushed some coolant through the leak in either the head or gasket into one of the cylinders. I have also checked all the spark plugs but it’s difficult to base it on that because they are under a year old and were all clean and showed normal signs. I’m betting it’s a head gasket but I wanted to get a second opinion. The engine is otherwise very healthy.

 

You could get an inexpensive borescope


pressurize the system again and take another look.

IMO the presumptive diagnosis should be cracked head rather than head gasket.

That said, I've had an infinitesimal leak for like about 10 years. A gallon of antifreeze every year or two is a lot cheaper than a Clearwater head.

 

what makes you think it is a cracked head and not the head gasket. Maybe the crack is so small and only leaks into a cylinder? And yes coolant may be cheaper than a head but I’m worried overtime it may contaminate oil and hurt my bearings.

 

Well, that's not exactly what I said, but from a statistical point of view the 0331 defect seems to show up a lot more than a head gasket alone. If with the borescope you show leakage into 3 and/or 4 that would be additional evidence pointing toward the head.

 

The only way you're going to get complete peace of mind is to change it out.

OTOH I've chosen to gamble (a little). I've blown up a pile of head gaskets on different engines and never damaged bearings. The resulting pudding from an antifreeze/oil mix isn't a good lubricant, but it's a lubricant nonetheless. It's a heckuva lot better than running out of oil and if you shut down right after the catastrophe starts you're usually fine. And not all blown head gaskets/cracked heads make pudding anyway.

Now, maybe if your pregnant wife is driving home alone 40 miles from an evening shift in the Bronx, priorities might be a little different.