Optical tack

98 4.0 jgcl new raditor thermostat water pump, burped with heat on high. New rod bearings, pistons, rings, lifters, oil pump, fuel pump, distrubter, cap and rotor, all sensors good, pulgs and plug wires Good, good oil pressure dosent over heat. Ticks after shutting off not the oil drip sound. No oil in antifreeze no antifreeze in oil no smoke out exhaust. At a certain point in accleration fades out a lil then comes back in steps. Turining the enigen over with wrench hear a hissing sound and tick kinda poping sound comming from oil pan. Simi ruough idel at all temps. Going to put some raditor stuff in to drop temp by 20 and some 108 octain booster. Tryed everything and i have no clue what could be wrong. Any suggestions. Altho the torque wrench i used was 6ftlbs off readjusted to compensate for the missing ftlbs and no chage. Orginal problem was broken pistion skirt. 270000 miles. I do hear what sounds to be an exhaust leak when on the throttle, the only thing i could think is headgasket didnt seat proplery.

cruiser54

I moved this to Grand Cherokee tech where you'll get more action.

Noah911

No pressure in the radiator? Since you mentioned putting something in the coolant mixture to try and drop the temperature by a few degrees, it sounds like you are saying that it gets too hot while it is running? If you truly are having a psi issue, and there is really no pressure in the radiator, then additives to the coolant is not going to be of very much help to decrease the temperature. What reasons do you have for saying no pressure in the radiator, and what are the symptoms? Is the coolant boiling and steaming in the overfow reservoir? If pressure in the system is not being increased from the ambient air, the boiling point will be much lower than needed, and you will see that causing the coolant to boil. I am sure you probably know, but you didn't say. Is your radiator cap good? The cap increases and maintains the systems pressure. If I was having a psi problem within the cooling system, that would be the very first thing I'd change, putting a brand new cap on the radiator. Are you loosing any coolant? With an improperly pressurised cooling system, the coolant may be lost as steam from the boil over. Coolant may also be lost from a bad head gasket if that were the case too.

If thinking possible head gasket issue, I would check that out with testing. Compression test. Leakdown test. Visual Inspection: coolant leaking into a cylinder will power wash the carbon off the cylinder head which can be seen and evaluated with an endoscope through a spark plug port. With the engine on and running, are you seeing bubbles in the overflow resevoir from leaking exhaust gases into the coolant?

The tick, acceleration fade, and semi-rough idle may not tie in, and possibly be related to some of the other recent work?