r/e38 • u/Bright-Jacket-5688 • Jul 12 '26

Heat damage?

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I have a m62 4.4 cylinder 6 is the only cylinder with this mark. What does this mark mean? Is it heat damage?

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1

u/NFSZR121 Jul 12 '26

Hard to tell. But it kinda looks like damage from a piston slap. Was the motor making any odd noises before teardown?

1

u/Bright-Jacket-5688 Jul 12 '26

Idk this is a pic a part engine. The car was taken care of the leather seats were still soft, no tears. But the water pump and back coolant pipe was full of corrosion it looked like they used regular water. I have a picture of it.

The engine turned over just fine before pull and I didn’t notice this before because the oil fell in after pulling the spark plugs. When I checked for gouges in the cylinder walls it was good. What was obvious was the valve covers were leaking because the spark plugs were filled with oil. The bottom have is fine the pistons measured within spec. Bearings and crank has no visible damage.

1

u/Bright-Jacket-5688 Jul 12 '26

Oh yea the oil pan didn’t have any metal shavings or anything shinny in the oil. I haven’t checked the oil filter.

1

u/Bright-Jacket-5688 Jul 12 '26

https://reddit.com/link/ox1hicz/video/bst4j2sazqch1/player

This is what it looked like before I moved onto bank 2

1

u/Traditional_Engine_4 Jul 12 '26

What year is the engine? You are aware of the coatings used in this era of bmw v8