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Discussion Starter · #1 ·
I've scoured google and many forums to try and locate information/photos of where the actual issue physically exists with the Theta II bearing problem. All I find are endless articles about the recall, litigation, the bearings failing, I get that and it's not what I'm looking for. To my understanding, there are shavings somewhere inside the crankshaft oil passages potentially blocking or reducing oil flow to main bearings. However, I can't find anything on a "fix" so to speak. A common thing with Ford 6.0 diesels is "bulletproofing" them, which basically amounts to a rebuild that also fixes the factories original shortcomings. For the Hyundai issue, does swapping a reman crank with new bearings in, or properly cleaning the passages of a Theta II crankshaft remedy the problem if there hasn't been damage yet?
What this stems from is my brother has an opportunity to buy a 150k mile Sonata Hybrid for almost next to nothing with what I can tell is a intermittent failing fuel pump, which is an easy fix.
I have been wrenching on cars/engines for a long time and have my A&P certs so engine overhauls are routine and not a problem for me. All I want to know is physically, where is the issue? Shavings inside the crank? Shavings left on assembled rod bearing surfaces? I can't find photos of anything other than parts from engines that have already suffered catastrophic failure.
 

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You need to read the translation of the Korean whistle-blower engineer...it states (as best as I can relate), that there is not sufficient cooling to the cylinder water-jackets. This is especially noted in cylinders 2 and 3 where they actually warp into an oval or egg-shape. Original "shavings" explanation was only to by them time...or put off the inevitable!
 

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Discussion Starter · #3 ·
You need to read the translation of the Korean whistle-blower engineer...it states (as best as I can relate), that there is not sufficient cooling to the cylinder water-jackets. This is especially noted in cylinders 2 and 3 where they actually warp into an oval or egg-shape. Original "shavings" explanation was only to by them time...or put off the inevitable!
Thanks for the info. I can't seem to find anything though about stating a cooling inadequacy was the cause of failure. How would that cause rod end caps to turn black from heat, friction and oil starvation?
 

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How would that cause rod end caps to turn black from heat, friction and oil starvation?
This is the basis for the class-action award...you would have to ask an engineer. I can mention that mobax (a contributor here, and mechanic), has said the previous Theda I (non GDI) didn't have the issues. The pistons and rods were of a sturdier design.
 

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2015 Sonata Limited 2.4 GDI non turbo 40k miles
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There may be more than one reason for failure. The metal shavings produced by manufacturing process was only the beginning. My opinion is the entire engine design and engine management have been stretched to the point that in certain specific driving conditions/habits, there starts to be severe mechanical wearing and sudden failure.

In the video below I describe what may possibly be one of the main issues, but keep in mind there may well be more problems with the design of these engines.

 

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Yes, opinions are like the anal orifice...everyone has one. Mine is the original engine with mostly hi-way miles, ECO mode does nothing on the GLS but light-up when you're not accelerating too fast...it doesn't change shifting rpm's.
 
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My Tucson has had a recall for a knock sensor. It's the nu 2.0 engine. Non turbo. As someone stated, I think it's an overall design flaw. If the cylinder is ovaling out, this would make sense. When I took my car in this weekend, they had a piston on the desk and rings were hammered. The now oval cylinder may be destroying the rings.
 

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Discussion Starter · #8 ·
There may be more than one reason for failure. The metal shavings produced by manufacturing process was only the beginning. My opinion is the entire engine design and engine management have been stretched to the point that in certain specific driving conditions/habits, there starts to be severe mechanical wearing and sudden failure.

In the video below I describe what may possibly be one of the main issues, but keep in mind there may well be more problems with the design of these engines.

Interesting, and thank you for the info! So what I'm starting to get in general is that it was just an overall poor attempt at an engine design. With the hybrid Sonata my brother is looking at, I'm also wondering if the hybrids tend to go further because the engines probably work a little bit less since they're being augmented by the electric drivetrain.
 

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Discussion Starter · #9 ·
My Tucson has had a recall for a knock sensor. It's the nu 2.0 engine. Non turbo. As someone stated, I think it's an overall design flaw. If the cylinder is ovaling out, this would make sense. When I took my car in this weekend, they had a piston on the desk and rings were hammered. The now oval cylinder may be destroying the rings.
I see. Maybe the reason I haven't seen any kind of rebuild/corrective procedure is that the whole motor is just inherently flawed then.
 

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From what I understand (if I remember correctly), the hybrid and the ECO's were made in Korea and are not part of the class-action suit.
 
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Hyundai isn't the only company to struggle with GDI design, VW, Toyota etc had issues. The other important part of buying that struggling Sonata is all that added hybrid tec. Family members had major issue with that. Dealer $12k repair estimate on car with 180k kms meant car was junked. GDI plus hybrid....a big no.
 

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I'll open mine up. Due to many, many very crappy circumstances, I have to file bankruptcy. But since I am! I am going to finish what I started and see the actual damageas I'm going to be calling the lean holder and letting them know the state of the vehicle, and my filing bankruptcy, so they can come and get it!

But I had an ass load of bearing shavings in my pan. And no sign of failure prior to 1\2 mile of it failing. But I am an aggressive driver admittedly, albeit I do take care of my vehicles.

Will post more in the coming weeks. I have a lot going on from hours cut back at work due to no one scheduling vehicle repairs, child support 'deliverancing' me, sonata seizing up, currently homeless since couldn't take narcissistic exes emotional abuse and had choice words about it, etc. Etc lol. But I will do my damndest to see what the actual damage is for us common folk.
 

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Why won't they cover a new engine for you?
 

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Thought I'd stick my hose in. Because of the poorly designed block assembly, cylinders become out of round, rings wear, shavings fall into the oil pan, then up through the pil pickup tube into the oil pump where they eventually stop the oil flow and then the domino effect, one part fails after another.

Also, wanted to add have had an experience with engine knock and the P1326 code in that when the rod bearings failed, in this case cyl 3, the rod
bearing to crank clearance became greater causing the piston/rod to travel farther up the cylinder and then the compression ring struck the ridge and
it fractured. Kia denied the lifetime warranty because of no compression in cyl 3, did a leak down 94% air coming out the dipstick tube.
However, after my reasoning, told the dealership to pull the pan and check the clearance at #3 cyl and what do you know, they didn't pull the pan,
but agreed and installed another engiine.
 

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(y)...but please keep your hose out of it! :ROFLMAO:
 

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shavings fall into the oil pan, then up through the pil pickup tube into the oil pump where they eventually stop the oil flow
I would think the oil pickup screen and oil filter would block massive amounts of debris from clogging oil passages.
I don't have the answer, but I don't think the above is the answer either.
 

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I would think the oil pickup screen and oil filter would block massive amounts of debris from clogging oil passages.
But enough may restrict oil flow/pressure...it's as good a theory as anyone has, or that we're going to hear about from Hyundai!
 

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I would think the oil pickup screen and oil filter would block massive amounts of debris from clogging oil passages.
I don't have the answer, but I don't think the above is the answer either.
Don't forget, the shavings drop into the oil pan and go to the pump before entering the filter, so that isn't part of the equation. The oil pump has no pickup tube, there is an opening in the bottom of the oil pump and just above the opening there is a screen that gets clogged with the debris, oil flow stops, engine kaput.

Old guy here, and I mean old, but reminds me of the plastic teeth GM used on the V8 cam gear to help keep things quiet. Great idea, but after many miles the plastic became hard, brittle, cracked and fell into the oil pan. Now GM had a screened pickup which sounds great, but if for some reason the screen became blocked, which it did when filled with all the plastic, there was a relief valve that would open and draw oil directly into the pump, oil along with the plastic, and in a short period the plastic caused major engine destruction.
 

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there is an opening in the bottom of the oil pump and just above the opening there is a screen that gets clogged with the debris
I've seen no mention of a clogged pickup screen on the Theta II.
Also, I've seen the result of a clogged pickup; [with loss of overall oil pressure] the first thing to go on an OHC engine are the cam bearings [because they are at the top of the engine]. [/edit]
 

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Thought I'd stick my hose in. Because of the poorly designed block assembly, cylinders become out of round, rings wear, shavings fall into the oil pan, then up through the pil pickup tube into the oil pump where they eventually stop the oil flow and then the domino effect, one part fails after another.
Out of round cylinders will also have the skirt 'rub' against the wall, this added friction may reduce the oil film at the rod bearings causing physical contact between the bearings and the journal - bearings start wearing/shaving off. Maybe at some amount of cylinder ovality the skirt/cylinder wall contact starts increasing exponentially, same for the bearing wear. But I'm still baffled about the way these failures happen. Almost no owner reported knocking or slowing down prior to the sudden failure moment. They all talk about a sudden engine shut down out of a blue, just like you turn off the ignition. If there is sudden oil starvation, the engine will still go for a few minutes with enough of noise before seizing and shutting down. Short skirts, short conrods and low tension compression rings would exacerbate this. Recipe for disaster. 'Maybe' (just my theory) the very low revving engine management is the starting point of all this - in the Eco and Normal modes these Theta engines are cruising at only 1000 rpm at speeds of 25mph and 40mph, even when you drive uphill or try accelerating a little, the engine just doesn't drop a gear, it stays there at the crazy low 1000 rpm struggling out of torque = piston to cylinder contact
 
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