Its a 28 year old engine you have time working against you. All the seals are shot, thats a given.

A leak down test will tell you if compression is leaking past the pistons or valves. Also it will tell you if just one cylinder is low or all of them are low, ect.


If its the valves you just need a valve job. I don't know what one of those will cost on a 617, probably $1k+/-.

If the rings are shot you are looking at a complete rebuild or replacement.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200