I have a 94 chev k3500 6.5td w/auto tranny. My check engine light is on but there are no codes. It takes a few cranks to start, then gurgles for a few times and settles into an idle. When revd up under a load it will spin up to about 3700rpm then it starts sputtering as if it hit a rev limiter. Ive checked for air in the fuel lines with a clear hose, no bubbles found. I also changed the oil about 100 miles ago as it was a thick black tar, but now the new oil is milky. Ive gone through about a gallon of water in the radiator since i last changed the oil too but there are no visible signs of leaks. I dont know if theres 1 problem that would explain all of this or a couple different ones. What could it be?

 

Correction, it acts like it rev limits at 3300 rpm

 

It does rev limit there its a diesel not gas itvwont do 5000rpms. And you probally got bad headgasket and cracked heads

 

Truck yellows at 3500 so i would think itd rev limit a but higher than 3300... But i guess its possible. I pulled the heads tonight. Head gaskets were fine, did not see any noticeable cracks in either head however all 8 injector cups had some cracking. I wouldn't think this would lead to water in the oil though, would it? Did not see any fuel in the radiator and the radiator hose wasn't very hard when it was running. It did kick out a brief cloud of white smoke when i started it today.

 

Gm wasnt very knowledgable with diesels in the 92 model year they had yellow line at 4000rpm same motor and rev limiter when u had heads off did u check cylinders for cracks to especially #8

 

Cycle all the pistons to the bottom of their stroke and check cylinder walls for cracks.