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=Issues with the TDV6 3.0 Engine=
:[[File:ClipCapIt-241107-221322.PNG]]
The crankshaft has sliding bearings made up of two half-circles, which do not touch the crankshaft journal during operation; there is a thin oil film between the main bearing and the main bearing journal.
:[[File:ClipCapIt-240402-190900.PNG]] [[File:ClipCapIt-240402-190938.PNG]] [[File:ClipCapIt-240402-200225.PNG]]
The lower half-circle has a hole through which oil enters between the bearing and the crankshaft. The crankshaft also has a hole that channels oil to the connecting rod bearing journal via an angled bore. The upper half of the main bearing does not have a hole; it sits in the main bearing cap, which is stronger than the lower part and absorbs most of the force from the piston impacts.
If the main bearing runs out of oil, it can seize onto the crankshaft within a few minutes, causing rapid wear and rotation in the engine block. If the bearing rotates, it blocks the oil passage in the block, preventing oil from reaching the connecting rod bearing and triggering a chain reaction.
Upon startup, during cranking, there is no oil pressure, so there is no oil between the bearing and the crankshaft. If this condition persists for too long or happens repeatedly, it can start to wear the bearing. If the bearing surface is no longer perfectly smooth, a chain reaction can begin. If a small piece breaks off from any bearing (even a tiny piece not visible to the naked eye), it can get between the adjacent bearing and the shaft, machining away further material and causing a chain reaction. Eventually, a bearing will seize, tighten, and major damage will occur.
If a bearing spins in the block, the crankshaft can break within 5-10 minutes, rendering the engine block useless.
Detailed explanation here (starts at 36 minutes):
https://www.youtube.com/watch?v=MKYovvWWym0
The camshaft chain tensioner is also oil-driven. Until there is oil pressure, it does not push the chain up between the two camshafts, which can cause a rattling sound for a few seconds at startup.
<br> This engine typically fails due to crankshaft breakage. But what causes this?
The most common cause of crankshaft breakage is crankshaft main bearing failure. It typically breaks on the side of the failed bearing.
The crankshaft can also break if there is too much clearance between the bearing and the shaft, because the bearing has excessive "play" between the four mounting points. High forces then lead to breakage. This is why the clearance between the bearing and the shaft must be within the factory-specified tolerance.
The crankshaft in the TDV6 can also break due to material defects, caused by poor design.
==Design Flaws==
Video: https://www.youtube.com/watch?v=v3moekbW6z8&t=2092
===Insufficient Lubrication on the Connecting Rod Bearings===
Despite being a 6-cylinder, 3-liter engine, it is incredibly short. This was achieved by having only 4 bearings supporting the crankshaft, and these bearings are also very narrow.
:[[File:ClipCapIt-240407-124641.PNG]]
So, there are two pistons between each bearing.
<br> Another issue is that the oil passages leading to the pistons are shared for the 4 inner pistons, affecting 2 connecting rod bearings: `:[[File:ClipCapIt-240407-125103.PNG]]` The oil enters the crankshaft through a hole located at the center of the main bearing. From there, it travels through angled passages to the connecting rod bearings. However, because there are only 4 mounting points and 6 pistons, the two central bearings (marked with a circle) supply oil to two places, one to the right and one to the left. This is designed so that the crankshaft journal has two holes at these points, offset by 180 degrees. As the crankshaft holes pass over the half-circle of the main bearing where the oil supply port is located, oil can be delivered to the left connecting rod bearing half the time and to the right one the other half. As a result, the oil pressure pulses for the inner 4 connecting rod bearings. It is always the two central bearings that tend to seize. <br>
===Excessive Force on the Main Bearings=== Since the engine is so short, with only 4 mounting points, the two central bearings are subjected to excessive force. Not only is it a problem that there are so few, but they are also very narrow to save space, allowing the engine to be mounted transversely.
===Oil Pump Issues===
There have been 3 iterations of the pump: the second one reinforced the pulley tensioner, and the third one increased capacity with a 15 mm thick rotor.
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=TDV6 3.0 gondjai=