Updated to SU5 and since I fly the Cessna 152 a lot for some sightseeing and short flights and since it was still selected after my last flight in SU4, I made a short trip (less than 20nm) in it after the SU5 update.
Much to my amazement the engines cut out after around 10nm, the prop came to a stop and I got an engine malfunction warning message.
Oh, where did that come from?
I never had one single engine malfunction since 2020 up until now with 2024 SU4 in any airplane and certainly not the Cessna 152.
Checked some settings, all the same as before. Re-flight, same flight again and again after +/- 10nm the same happened, engine malfunction. Hmmm... checked fuel quantity etc, all good.
Switched to the Cessna 172, no problem, no engine malfunction, switched back to the 152, same issue again, that's 3 times in row.
Started a search here, didn't find anything regarding the engine malfunction so did a Google search and this pointed to the https://forums.flightsimulator.com/ forum where it's mentioned at the start of the SU5 beta.
So... a bug crept in and hide itself.        

Just a thought - did you check fuel?

5 hours ago, Lange_666 said:

... checked fuel quantity etc, all good.

That's not the problem. After the first malfunction I raised fuel to the max.

https://forums.flightsimulator.com/t/c152-aircraft-system-failure-engine-malfunction-error/759514

Edited May 2May 2 by Lange_666

https://www.avsim.com/forums/topic/691181-aerosoft-crj-uncommanded-engine-shutdowns/#comment-5706245

I just made a post on the official forum about the C152 engine issue.

tl;dr disable Aircraft Stress Damage  (not Engine Stress damage)

(Or fly the Aerobat instead)

https://forums.flightsimulator.com/t/c152-aircraft-system-failure-engine-malfunction-error/759514/14

Edited May 3May 3 by Magenta Line