The D4FE engine is a full aluminium, Euro VI-compliant power unit that was developed as a replacement for the earlier D4FB engine. The D4FB was widely regarded as a reliable and durable diesel engine, known for its longevity and straightforward design. It served as a solid choice for many Kia and Hyundai models over the years, earning a reputation for dependability and ease of maintenance.
However, with the introduction of the D4FE, Kia and Hyundai aimed to meet increasingly stringent emissions standards and improve fuel efficiency by designing a completely new engine architecture. The D4FE was intended to be a modern, lightweight, and cleaner-burning powerplant that could comply with Euro VI regulations while providing better performance and efficiency.
Unfortunately, in the process of developing this new engine, it appears that the automaker’s engineers may have taken some shortcuts or made compromises to meet cost and regulatory targets. These shortcuts have manifested in design choices that compromise durability and reliability most notably, in critical areas such as the crank pulley setup and internal engine components like the oil pump.
The situation was further complicated when the D4FE engine was paired with a Mild Hybrid Electric Vehicle (MHEV) system. While hybridization offers benefits in terms of emissions and fuel economy, integrating it into an engine that already has inherent design weaknesses has exacerbated existing issues. The hybrid system adds additional loads, stresses, and complexity to the engine’s components especially the crank pulley and timing mechanisms highlighting and amplifying the engine’s vulnerabilities.
In essence, the combination of a new, ambitious design with cost-cutting measures and the hybrid system’s added demands has led to widespread reliability problems, making the D4FE-powered vehicles prone to engine failures that were not as prevalent with the older, more proven D4FB engine.
Hello sir, my story ,I rebuild the D4fE engine cuz xonrod was snapped in cylinder 4, put new piston, piston rings ,all seals ,new oil pump,all conrods, car works fine ,engine is good drives good too, the issue i have is since I rebuild the brakes doesn’t work good, I mean the pedal gets hard, so I changed servo ,master cylinder, put on mot brake test found that rear brakes are not discharging , so I put new rear disc ,new brake pads, but still the same story, front driver side break good ,passenger side 80 % good and rear brake not good ,I mean not working, the electric parking brake wirk fine, changed brake oil,,done brake bleed still not resolved,
My question is that does this engine have a brake vacuum pump on the gearbox side just under the camshaft ? I see the vacuum metal pipe comes from there and than connects to the brake hose for cylinder.
Will this be the problem
The oil pump (tandem pump) also generates the vacuum for the brakes so check that there is a vacuum pulling on the brake servo, if not there might be debris in the tandem pump or the seals were not re-installed correctly (there are seals between the pump and the upper oil pan/girdle and then seals between the upper oil pan/girdle and the block).
hi on a slightly different topic i have recently found two fault codes in my ecm [2021 tuscon] relating to oil pressure P122000 oil pump solenoid control and P055F00 oil pressure out of range not eml or oil light on only discovered them while doing a code scan for esc srs and other brake related faults which i believe to be possibly a wiring issue or abs pump fault.
oil level is correct and recently changed it gets changed every 8 to 10 000 klms and ive recently changed both belts car has just done 165 000 klms and reasonably trouble free
1.6 CRDi? There’s a solenoid in the side of the block that’s possibly clogged or failed.
hopefully thats it and no damage done havent needed to p;ug in diagnostics in over a year so dont know how long its like that seems to be running fine.