fluttering noise in turbo under load

kerry holley · September 19, 2006

we have a 2003 f-250 that has the classic flutter noise in turbo under load. ther are no codes present,and we have replaced the turbo,vgt,and reprogrammed per hotline suggestions.now hotline says to disassemble new turbo and inspect for sticking vanes-turbo has less than 100 miles on it.does anyone have any other ideas or run into the same problem?

Keith Browning · September 20, 2006

Kerry, welcome to the DTS! /forums/images/%%GRAEMLIN_URL%%/thumbup.gif

Two things you should do.

Never assume a reman turbo is properly operating. I have had two sticking right out of the box.
Before you go nuts or start pulling parts off of the engine make a data recording of the fluttering event. I find the VDR to be the easiest to use because you can drive safely with the recording button close by and you don't need an "assistant" to drive while you watch sun glare in the WDS or IDS screen. Once you have a recording you should be able to find the cause. If not you can upload your recording(s) to the Hot Line and have them take a look at it. /forums/images/%%GRAEMLIN_URL%%/laugh.gif

Joey Kaylor · September 20, 2006

keith-what exactly are you looking for on the IDS capture to prove its sticking? i'm supposed to be getting ours in later this week (been told that for a month now) and would like to see what all PID's are more important than others in various circumstances.

Keith Browning · September 20, 2006

Watch your pressure sensors, MAP, MGP, MAF AND EBP (yes, it's still there) VGTP#, RPM EGRVP and EGRDC#.

It takes time to get to understand what you are looking at with data and graphs but making the recording is the important part.

In the shop you can use pinpoint test KA to help you find a stuck turbo. Raise the RPM's to 1200 and monitor MGP and EBP while ramping the VGT up to 85%. You should hear the turbo spool up and see a small rise in pressure on the sensors. If you can't see a pressure change by running the VGT up and down then you are looking at a non-responsive turbo. Your job is to find out why!