Had the coil pack off and was changing plugs when I noticed what appears to be coolant leaking between #3 and #4. I'm not burning coolant at all. Haven't had to add any.

Plug 3rd from the left is #4. One side is clean the other is not, so it doesn't appear it's being completely washed by coolant.

Have the dreaded 331 head. Am I on the right track it's just the gasket? Thanks...

 

you can always do a oil test and see what results you get from that. That's how I found mine a few years back.

 

Can’t see any coolant the picture . Was there visible green coolant on the plug Or in the cylinder ? A plug wet with coolant would indicate a substantial head gasket leak. A plug with burnt white coolant deposits onto the plug itself would indicate a small leak. A “clean” “washed” plug typically indicates a leaky or sticking fuel injector .

 

It's that wet area above the Cam sensor. Plug wasn't wet........ Valve cover gasket is leaking, hence, all the grime. Been leaking for a long time before I got it this fall. Also, what is that connector attached to the block? Some kind of relay?

 

The spot you mentioned above the cam sensor is nothing . Half the 4.0s you’ll run into have some oil seepage on the same area there is no coolant jackets there only oil and little at that. Put your fresh plugs in it and a new valve cover gasket and drive it!

 

Ok, thanks. What about that relay, or whatever, bolted to the head?

 

That's a ground. And as far as your leak it looks like oil. Most leak in that same spot, I swapped my head gasket while I had my motor out and it had the same condition. Just throw some Lucas in there with high mileage oil and run it, you'll be fine.

 

Thanks. Thats the oddest looking ground. I'm used to just seeing a singe wire, not a connector like that, but I don't work on anything newer. Just older hotrods...

 

Can that relay looking ground go bad? The relay looking piece? if so, symptoms? Assuming it can.....
Also, where does the crank sensor wiring go to, I know the connection is by the tranny cable bracket. but then where does it go?
Thanks......6.5.0

 

My engine has a little seepage in that exact same area. No coolant in the oil (had it tested by Blackstone Labs) and no oil in the coolant = no worries! For now at least.

 

Thanks. Still would like to know what that ground is for if anyone knows ...

 

That actually looks like a fused ground link.

 

The crank sensor wires go directly to the PCM. One is 5v power, one is signal, and one is ground. That area of the head gasket only contains oil draining back to the pan around the pushrods. No pressure. The only pressurized oil getting into the head is thru the pushrods. That "relay" you talk about has a good Mopar number on it. Run the number and see what you come up with. It could be a knock sensor, but I've never seen one on a 4.0 before.

 

I'll have to run the number and see what I get.... Thanks....

 

I am with Dave on this one. Pretty sure that is the knock sensor.