S38 rebuild-regular part of ownership?

[SD-KC]

M5 is my dream car. It seems many have had s38 engine rebuilds. Is this just part of owning an m5? I get why you would rebuild due to over heating, oil consumption, etc. Is this just something to budget for when looking for an m5? If it hasn’t been rebuilt just know you’ll have to do it sometime after getting one?

If you rebuilt yours, why? If you haven’t, are you planning a rebuild or just running as is?

I did a search but didn’t find this exact topic. Sorry if this topic has been covered.

[Randomg]

If you keep it within the right temp range and don't flog it until it's warmed up, I'd say it's good for 200k. Over that the timing guides start to scare people, and old car stuff happens if you still want to drive it hard. Pistons, cylinder walls, valve springs all wear out. Exhaust valves can develop small cracks. Lots of stuff lasts longer that you can reuse during a rebuild, but people often just replace everything since they have the money and don't want to risk it.

Keeping it the right temp can be harder than you might think if you aren't careful about keeping cooling in good order. Losing too much coolant or letting the coolant gauge creep up fast into the red due to a fan issue can happen quick. Both have happened to me, first was a head rebuild and straightening, the 2nd a brand new head.

Some people drive them past 300k, but I'd say it's risky unless you're not driving it hard.

[Randomg]

Double post...

[Randomg]

Triple post

[Technician117]

I don't think it's different than any other car, or certainly not than any other M car engine. Maintenance history will help paint a picture of how prior owners treated the car/engine. As mentioned above, I think overheating and head issues are the main reasons for failures. That and the fact that this engine technology time period is advanced enough for fuel injection but not quite to the point where good diagnostics existed (check engine lights with code information). Because of that, some problems can go unnoticed or happen quickly and cause damage that requires a rebuild.

The engine in my M5 went almost 300k miles before something happened. I don't have the details as the owner that had the engine rebuilt is now deceased.