Quote:
Originally Posted by humfrz
I wonder what percentage of the failed, oil starved engines, failed because of a clogged screen?
Also, I wonder why the oil filter isn't filtering out this stuff? Or is it?
humfrz
|
Everybody is so focused on the really scary pictures of the pickup screen that they are ignoring another point of failure. When the engine is apart or when new sealant is applied there are several points where it can be directly introduced to the oil system. These points can be up or downstream of the filter and pick up tube. Any sealant that gets in there may never even make it to the screen or filter. It is not a safe assumption to think that all of the sealant passes through the pan where it can be captured.
The picture of sealant in the bearing oil channel and the written instruction specifically stating it can get there has been totally disregarded by many normally smart guys because they just can not get away from the mindset that that it will be captured by the filtering system. The system can not capture what never makes it to it. The updated instructions (which I can't find right now) make it very clear that the issue can either be old sealant that is not cleaned up properly or new that can cover or break off in the channels. As the picture below shows one of the most restricted passages are in the bearings. Only takes a small piece to be introduced to the system beyond the filter or pickup to float around in there and eventually block a bearing channel. This is why the most frequent failure we have seen documented was one individual bearing.
Personally I can't even blame the techs for the new sealant part of the issue. It is poor engineering that uses a flowing sealant so close to vulnerable oil passages. Just a tad too much or off by a couple of millimeters and bang a bearing is spun! The poor cleanup resulting in huge amounts of material blocking take ups is all on them though.
I sincerely apologize for coming across as preachy or self righteous on this subject but for 2 years I have been saying this was the problem with spun bearings right from the factory and have always been shouted down as a fool since it was "Impossible". The updated instructions and documents provided by Toyota/Subaru show that not only is it not "impossible" but under the right (wrong?) conditions it is actually probable.
I will now put my soapbox away and let the angry mod tell me yet again that I am wrong.
