This past weekend I picked up a 1999 Disco 2 with a 4.6 swap that was apparently rebuilt about 25k miles ago in 2023, (have invoices and pics of the build in process) however it seems that this engine may be a lemon that the seller was eager to dump instead of fixing. On the 250 mile drive home it consumed 1.5-2 quarts of 20w-50.
I also almost immediately got a CEL with codes for lean mixture on both banks, and misfires in cylinders 8/6/4, along with a couple other codes.
I did a compression test today, results are in the imgur album with pics of the plugs and the codes I got.
Plugs in 8/6/4 definitely seem sootier than the rest, but none of them look all that great to me. Just a bit confused at the compression readings because most people in the LR forums say a 4.6 is usually around 170-180, and my highest readings are over 200.
Just looking to get some opinions and maybe see what people with healthy 4.6s have gotten for compression readings. Definitely does not look good though.
Also of note is all 4 O2 sensors and both cats were replaced in 2025, and crawling underneath now I see all the O2 sensors have been fitted with non-fouler extensions. Definitely seems to me that the PO knew about the excessive oil consumption and it was ruining the sensors, although he denies this (because of course).