I'm in the middle of an LS1 teardown.

Last weekend I removed the valve covers to and found it hard to see anything, as the pictures below will evidence.

While I wait for an opportunity to resume the teardown this weekend, I wonder what could be responsible for making the insides so black.

I can say that the residue feels hard, scaly and not very oily. There are some puddles of oil around a few of the valves, so I expect some of the valve stem seals to be shot, but would that alone explain the all-round blackness of everything in this valvetrain?

Bank 2

Bank 1 Close-Up

  • Can you give us some insight on the maintenance history of the car? Perhaps also a photo of the dipstick's end?
    – Martin
    Commented Mar 2, 2017 at 12:33
  • 1
    Looks like it got very hot. Not sure. Interested to hear what it may be or what else you find as you continue your tear-down.
    – CharlieRB
    Commented Mar 2, 2017 at 12:55
  • @CharlieRB you can follow the updates here
    – Zaid
    Commented Mar 2, 2017 at 13:24
  • Do you remember this answer? ... while I don't know if this was a lack of oil, same thing applies. Craptacular maintenance done; craptacular results ensue. Commented Mar 2, 2017 at 23:40

1 Answer 1


Classic residue from an engine not worked too hard with low oil change intervals. Stripped and re-built 3 V8's which had that residue (all had done in excess of 100K miles). Took the block and reusable parts to a machine shop to get them cleaned in a chemical hot cleaner. Re-built engine went into a v8 short wheel base land rover (160bhp and quick...)

  • So is the residue oil or fuel?
    – Zaid
    Commented Mar 2, 2017 at 13:17
  • @Zaid : residue is Oil. if it was fuel - then that amount over time would dilute the oil and it would seize rapidly...
    – Solar Mike
    Commented Mar 2, 2017 at 13:18
  • 1
    @Zaid so budget for new hydraulic lifters straight off and camshaft...
    – Solar Mike
    Commented Mar 2, 2017 at 13:20
  • This is a pushrod engine
    – Zaid
    Commented Mar 2, 2017 at 13:21
  • Yes, and the lifters or hydraulic tappets sit directly on the camshaft between the pushrod end and the cam. At least it seems like that from what I see in the picture - is this the first one you are taking apart?
    – Solar Mike
    Commented Mar 2, 2017 at 13:27

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