I got a boost pressure check engine light on .. I have a 2011 Peterbilt isx15 2250 with 470800 miles on it.. truck will run good throughout the day and than I’ll have boost problems out of no where.. check engine light comes on and boost pressure valve not hits 15 -19 psi.. and than light comes off and boom back to normal.. any suggestions what it is
Something rattling around in the exhaust somewhere, sometimes restricting and sometimes not ?? Do you have a pyro ? Is it higher than normal when your boost drops? Could be the turbo itself too. Next time it happens pull the exhaust pipe off the turbo and see if boost comes back. You should have a look at the inside's of your turbo too. Any other codes ?
When was the last time you changed your manifold air pressure sensor.
I don’t here anything rattling I’ll pay more attention to that tomorrow, and yes sometimes it restricts and sometimes not, no pyro, ok I’ll check the turbo when it happens again and I don’t have any other codes.
Probably never I bought the truck a month ago but where would that manifold air pressure sensor be?
I just found where it’s located..
Thanks rawze I’ll change those out and we’ll see what happens
How do you know the fault is for boost pressure? The symptoms sound like a fault code that applies a derate.