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akains · 11-01-2025, **(Subject: 8.3 ISC turbo flutter/surge )**

Hey there, new to the forum and seeing lots of good info. I am working on an ISC8.3 2250 that has been de-mandated. Im getting a lot of turbo surge when you are under load at 1200-1500 rpm and quickly let off the throttle. I was thinking it was part of the file but I put stock file back on and can get it to do the same thing with harder load and throttle release. Can sticking vanes in the turbo cause this? Or beginning failure of the actuator? I have no codes and it runs really well going through all gears, exhaust brake, boost etc is fine. It is only under heavy throttle and quick to let off that it will flutter. any ideas? thanks!

hookliftpete · 11-01-2025, **(Subject: 8.3 ISC turbo flutter/surge )**

If you suspect turbo actuator you might try recalibrating turbo and see how it responds or if it fails

Rawze · 11-02-2025, **(Subject: 8.3 ISC turbo flutter/surge )**

(11-01-2025 )akains Wrote: Hey there, new to the forum and seeing lots of good info. I am working on an ISC8.3 2250 that has been de-mandated. Im getting a lot of turbo surge when you are under load at 1200-1500 rpm and quickly let off the throttle. I was thinking it was part of the file but I put stock file back on and can get it to do the same thing with harder load and throttle release. Can sticking vanes in the turbo cause this? Or beginning failure of the actuator? I have no codes and it runs really well going through all gears, exhaust brake, boost etc is fine. It is only under heavy throttle and quick to let off that it will flutter. any ideas? thanks!

The most likely issue is that the turbo is over-spooling all the time, trying to warm up the missing DPF/DOC cans due to horrible delete tuning that does not have any engine mode control re-mappng ... and of course, the factory file is going to have similar issues, as it is trying to do the same thing. - Engine is likely permanently stuck in rapid 'DPF warmup' operating mode. Its the most common problem that bad deletes have, and the main symptom is turbo spooling up and trying to make boost / trap heat at idle, etc.

copy the program out of the ecm and e-mail it to me for a review of what someone did in there. At least that way your not spending moneys on expensive components (and eventual failures due bad delete tuning) and also guessing blindly at your issues.