V8卡車發動機機油更換中的金屬屑


1

本週末,我正在更換2004年Chevrolet Siverado 1500的機油,當我要重新插入塞子時,我注意到磁性油塞上粘有一些細小的線狀金屬屑。它們的長度從大約1/8"到3/8"不等。刨花略微捲曲/扭曲,但厚度與鋼絲刷上的厚度大致相同(很小的一毫米)。

我的問題是,我應該怎麼擔心?是時候開始購買新卡車了嗎?還是這個預期的磨損?

一些背景信息和背景信息可能有助於回答這個問題:幾年前我購買了這輛車,目前行駛了190,000英里。它運行得非常好,我每隔3-5000英里就換一次機油,並且不要花很多時間(也許每年5-8000英里)。可能也很相關:一天前,我們買了一個新露營車,我正將它拖回房屋(約90英里)。我保持了合理的速度(最高時速60英里/小時),我懷疑這是這輛卡車拖過的最重的拖車(空載4200磅,卡車的最大牽引能力為6100磅)。我確實知道以前的主人用卡車拖了一條小船(不知道多遠或多久一次)。我懷疑這可能是引擎"闖入"以適應重載牽引(我聽說引擎和/或變速箱在牽引時會磨損不同)。這聽起來像是一個合理的猜測,還是我應該擔心的其他事情?

2

Because anything which could be said here as an "answer" is a guess, here's what I got for you. It would be my best guess there's an issue somewhere in the valve train and its wearing out. Most likely something is happening with the lifters and/or camshaft. It might also be there's an issue with the rocker arms, but less likely. My reasoning behind this "guess" is because there are really few parts in the LR4 engine (or any LSx style engine) where magnetizable shavings could be coming from.

There are two things here:

  1. Until the engine is opened up and examined, you won't know what's going on. Nobody can really tell you "this is the problem" for sure until it is opened up. Until then, it's a best guess.
  2. The engine would have been broke-in longggggg ago. Whatever is causing the metal shavings is a new event and new wear which should not be happening. Any engine which has any type of metal shavings in the oil (as you describe) is not in very good shape. It could die at any time and will only get worse with time. This engine is going out and there's no bandaid which is going to stop it. Only opening it up for inspection and replacement of the affected parts is going to solve its issues.

Good thing here is, if it is valve train related, you should be able to have the engine gone through with new parts for relatively cheap. An even better proposition here would be to get a replacement engine from a junkyard (or off of eBay or CraigsList). GM made a TON of the 4.8L engines for their trucks (they made even more of the 5.3L ones), which makes them fairly easy to find. It also makes them cheap. Under normal circumstances, the LSx engines can last for 250-350k miles without an issue with proper maintenance. I'd definitely suggest your circumstances aren't normal and it does happen.

Hopefully to make you feel a little better about the whole thing, from what you describe in your towing and maintenance, I doubt there's anything you've done which directly cause the problem or which you could have done better to prevent the issue in the first place. More than likely, whatever is going on has been happening for a while, just now it's happening at a lot faster pace. Something is misaligned enough where major wear is happening at an accelerated pace. You'll need to get this fixed sooner rather than later, as it isn't going to get better on its own.