Engine/Transmission (1994 - 1998) piston oil cooling nozzles

[mschoenheider]

While repairing a dented oil pan on my truck, I found two piston cooling oil nozzles sitting in the bottom of the drain pan. I could not determine if the ends of the nozzles that fit into the block were cracked (part still in the block), or if the nozzles were still in one piece. I purchased the truck with 120k and it currently has 132k. I generally drive at 5,000 to 8,000 feet, and my EGTs seem pretty high for my level of fuel. I have hit 1400 pre turbo with an empty truck once while not paying adequate attention to the gauge. I have a few questions. First, are the nozzles pressed into the block, or do they use some other form of anchoring? Is it possible to replace the nozzles with the engine in the truck, dropping the oil pan was no problem. How long are the nozzles? With two nozzles missing, I would think that oil is still spraying up to the back side of the piston, but there would actually be more oil flowing, as long as the oil pressure remained close to the same as when the nozzles were in place. My oil pressure seems about normal. Could the lack of the two nozzles be causing my EGTs to be above normal, or are my EGTs normal for the elevations that I drive? Any help or suggestions would be greatly appreciated.

 

[78repowerwagon]

The cooling nozzles go in above the upper main bearing shell, The crank has to be pulled to replace them. As far as temps, I don't know. If it were my truck, I would pull the engine and replace them. It would be alot cheaper than a scalded piston. I would guess the oil doesn't have enough pressure or volume to squirt oil without the pressence of a nozzle.

 

[A Johnson]

I don't have a nozzle handy to look at but they are about 1"- 1 1/2" or so long. Approxamatley 3/8" stick above the casting for the main web and point towards the piston , except for #1 which is even or a little below the casting. They have a small shoulder on the bottom side so that oil pressure can't push them out of the block.



If you have the complete nozzle, they were probably left in the pan during engine assembly. If you only have a short piece then I would guess that the tops were broken off somehow, and they are probably still squirting oil on the piston.



You could pull the pan and reach up with a mirror or your hand and see if they are still there.



I doubt that they are affecting your EGT, although with high EGT and if the nozzles are indeed missing, your ring and piston temperatures would really skyrocket.



A Johnson