coolant in oil, valve lifter damage, 6.5,1998

[petersin]

70,000 miles. Popping Noise in intake port. Removed right valve cover, found sludge despite very frequent oil changes. Probably water in oil, Any common or specific reasons for the 6.5, beside the typical head gasket thing? Water pump passage through front cover?

But worse!, the top insert under the snap ring in all valve lifters was dislodged and the push rods jammed into the lifter, has this happened to anyone? sludge and lifter thing a coinsidence? never used ether. push rods not bent. Timing chain? piston hitting valves? it had no unusual noises.
Thank You

[DmaxMaverick]

Sounds like just a head gasket, or in a worst case scenario, cracked head or block. The lifters sound normal. At rest, valves under load will colapse the lifters after a while. They are hydraulic, and the oil will bleed off. You'll be having the head off anyway, so any internal damage will be evident. Before you pull heads, you should do a cooling system pressure test, to confirm the source of the leak.

[john8662]

Replace the pushrod and the lifter that had the retainer pop off. The pushrod will be worn from riding improperly on the cup, and well, the lifter's spring could be damaged at that point. Yes, I've seen one like this during a 6.2 tear down. Not sure what the cause is. Probably due to the assembly of the lifter and the retaining clip either being inserted improperly or manufacturing problem with the lifter or clip itself.

Sludge?

An oil analysis will reveal the truth of whether there is coolant in the oil. The bad news is that if there is coolant in the oil, and you've got a 97+ block, it's usually a cracked block, not a head gasket.

A compression test after re-assembly of the valve train will be necessary to diagnose a failed head gasket.

I'll post a pic of the lifter that I found later, see if it matches what you're seeing.