Hyundai GT1749S Turbocharger for Mighty D4AL 3.3L | OEM 28230-41730

Technical Q&A: Hyundai Mighty Turbocharger

What causes oil seal leaks and blue smoke in Hyundai D4AL GT1749S turbochargers?

Oil seal leaks in GT1749S turbochargers are typically driven by high crankcase pressure or oil drain line restrictions. On the 3.3-liter D4AL engine, worn piston rings can allow blow-by gases to escape into the crankcase, raising internal pressure and preventing the turbo oil from draining naturally into the oil pan. This restriction forces pressurized oil past the turbine shaft oil seals, leading to carbon buildup in the exhaust housing and blue smoke. To prevent repeat leaks, always check crankcase pressure, clean the oil drain line, and replace the engine oil and filters during installation.

Is the GT1749S 28230-41730 turbocharger compatible with older 3.3L D4AL engines or Chorus buses?

Yes, the 28230-41730 is fully compatible with both the Hyundai Mighty II truck and Chorus bus equipped with the 3.3L D4AL engine from 1999 onward. Under the hood, this unit serves as a direct-fit replacement for BorgWarner and Garrett reference numbers 708337-0001, 708337-0002, and 708337-5002S. It also interchanges seamlessly with Hyundai part number 28230-41720. Always verify your vehicle’s build year and original nameplate to confirm correct oil connection angles, as early or non-turbo variants of the D4AL engine may utilize different oil feed flanges.

What is the critical priming procedure for installing a new 28230-41730 turbocharger to prevent dry start?

A dry start is the primary cause of immediate bearing failure in new turbochargers. During a cold engine start after installation, the oil pump takes several seconds to deliver oil to the upper valvetrain and the turbocharger. To prevent dry-friction scuffing, pour clean engine oil directly into the oil inlet port of the new GT1749S before connecting the oil feed line. Spin the compressor wheel by hand several times to distribute the oil across the journal bearings. Additionally, disable the fuel pump fuse and crank the engine for 10-15 seconds to build oil pressure before allowing the engine to idle.

How does the water-cooled bearing housing on your GT1749S turbocharger improve Mighty Truck fleet reliability?

Our GT1749S features an integrated water-cooled bearing core jacket that connects directly to the engine’s coolant circuit. In commercial vehicles like the Mighty II truck, heavy-load cargo hauls raise internal turbo temperatures significantly. When a driver shuts off the engine immediately after a hard run, oil remaining inside an oil-only turbo will instantly bake and carbonize, forming hard sludge that scores the bearings during subsequent starts. The water-cooling jacket continues to dissipate residual heat through a natural thermosiphon effect after engine shutdown, completely preventing oil carbonization and significantly extending bearing life.