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Since VGT% is a command and not what the actual vanes are doing it's a tough call.
Shouldn't normally see either 85% or 15% at any given time. Although some have perfectly fine running engines and will see 85% occasionally at idle.
What is your max boost and do you experience any abnormal turbo lag? Black smoke?
Josh
No black smoke. Was going to get some boost numbers on the way to work this morning but the engine never fully warmed up and traffic wouldn't allow it anyway. Turbo lag...nothing unusual that I can detect. It all started after I put the cold front back on. I'd take it off to see if that would help, but ECT never got over 190 in a 20 minute drive in 28 degree weather this morning, so a lack of air movement doesn't seem to be it. It's not like the cold front is blocking the only air into the engine bay. While some would say that holding heat around the engine would have nothing to do with how quickly the EGTs drop, there's no doubt that before I ever got the cold front, my EGTs dropped faster in the winter than in the summer.
I may sound like a broken record on this, but EBP readings compared to VGT% command should tell you if the vanes are stuck.
On the EGT temp. Personally, don't care to have the oil in the turbo sitting in 400 deg. I also block up the rad. Slows EGT cooling in the winter, however dropped faster with each exhaust tweak.
Just a stab in the dark, could anything have changed in the exhaust further back causing a restriction now? Muffler/Cat... Are EGTs otherwise normal for ya?
I may sound like a broken record on this, but EBP readings compared to VGT% command should tell you if the vanes are stuck.
On the EGT temp. Personally, don't care to have the oil in the turbo sitting in 400 deg. I also block up the rad. Slows EGT cooling in the winter, however dropped faster with each exhaust tweak.
Just a stab in the dark, could anything have changed in the exhaust further back causing a restriction now? Muffler/Cat... Are EGTs otherwise normal for ya?
No recent exhaust changes, other than 235k miles of accumulated soot. I do recall thinking recently that my EGTs seem to run a little higher than I expected, but I typically have to get on it a little to get an EGT over 1000 even. How do you evaluate the EBP and VGT numbers to tell if vanes are stuck?
Set aside WOT and very large power changes. Driving easy you should see the EBP values be somewhat consistent. Like in the range of 23.xx I do not know if the value varies much truck by truck. VGT% will vary to hold the EBP somewhat in that area. Definitely if you see VGT% change and do not see EBP follow then I would suspect stuck.
When letting off the throttle EBP will drop and VGT% will but up to bring it back and both settle.
Hope that makes sense.
Set aside WOT and very large power changes. Driving easy you should see the EBP values be somewhat consistent. Like in the range of 23.xx I do not know if the value varies much truck by truck. VGT% will vary to hold the EBP somewhat in that area. Definitely if you see VGT% change and do not see EBP follow then I would suspect stuck.
When letting off the throttle EBP will drop and VGT% will but up to bring it back and both settle.
Hope that makes sense.
I'll watch that over the holiday and see what happens. Thanks and Happy Thanksgiving!
I hear you on the thought of letting 400° Oil sit in the turbo
That thought did cross my mind the other day
So on that note I'm sure one you guys have one of those cool laser temperature guns would one of you be willing to take the temperature of the turbo itself and then compare it to your EGT gauge
I get the feeling that the temperature of the EGT gauge compared to the temperature of the turbo itself is going to be quite a bit different
Another thing to think about is the placement of the EGT probe itself is a pre-turbo or post turbo
And even though and EGT gauge is an aftermarket modification you still can compare it to all the other temperature gauges to verify the accuracy of the gauge itself after a cold so just like you would any other temperature gage
If your EGT's are 400* when you shut it down, your oil isn't 400*. If that were true, what happens when we're pulling a hill with a load, and EGT's hit 12-1300?
Guess I need to make a video with the infared thermometer.