Boost pressure way down???

[BHolm]

This is my first trip out of the mountains in the '06. I was seeing as much as 30 psi on my Westach gauge around home, and 27-28 pretty easily. I have it MN right now and it seems to struggle to hit 23 psi. Still seems to have all its power. The boost line for the gauge seems OK. Any idea what is going on? I did run it through a carwash on the way. I suspect it sucked some moisture into the filter because the minder was pegged. I checked the filter and it looks like it should at 4500 miles. It isn't water soaked or frozen so I think that can be ruled out.



What should I see for boost pressure? With cold weather have an effect? It has been right around 0 degrees.

 

[Buffalo]

BHolm,



I'm no expert in these matters but, could the difference in elevation between CO & MN cause that much of a difference?



Did you get the higher boost levels going uphill in the mountains of CO & now you're in flatter country where the engine isn't working as hard to get you where you want to go?



Possibly a small leak in the pressurized part of the air intake system?



I hope it turns out to be nothing serious, for you.



Joe F. (Buffalo)

 

[BHolm]

If anything I think I expected the same or more boost at low elevation. Of course, I am no expert either I'm going to hook up a small trailer and see if a little load will bring the pressure up.

 

[Bertram65]

My truck is doing the same thing right now, the only thing I can think is it's the gauge, I am going to hook up another gauge with new hose and just run it from the boost bolt out the hood into the cab through the door and check it. I went from 23-24psi to 18psi, truck does not feel any different. We got a lot of rain the last week so perhaps it has some moisture in it and that is causing it.

 

[Buffalo]

BHolm,



That sounds like a good idea, to me, also.



BTW, you may want to read the thread on "Crankshaft Sensor TSB". Especially, "Buzzer's" reply. Click on the link he provides, from the DTR site. I don't know if it will apply to your truck but, if it does, it may save you some problems, in the future.



Again, Good Luck.



Joe F. (Buffalo)



Where do you live in SW CO? I used to go to Norwood, CO, every year, for about 10 years. That part of CO is some of the most beautiful country I've ever seen.

 

[hasselbach]

Mine runs lower pressure when really cold out. Im thinking that lower temps equal lower pressure due to the intercooler really cooling the charge (thus lowering the pressure).

 

[Cattletrkr]

Hasselbach might be on to something there. I've always kinda wondered about that. I see lower boost in the winter. I figure between winter fuel, colder air being harder to pump, and colder intake temp, it's normal. I wonder if the oil on AFE's and K+N's gets thick when it gets cold and causes a problem???



HOWEVER, you're seeing too low of numbers.

 

[coobie]

Mine runs lower pressure when really cold out. Im thinking that lower temps equal lower pressure due to the intercooler really cooling the charge (thus lowering the pressure).

I think you are correct hasselbach,I pull lower fuel pressure in colder weather with the Fass system installed also. I had my fuel filter and water seperator filter changed this past weekend and the psi on my autometer fuel gauge was the same as before the filters were changed. coobie

 

[rbattelle]

I suspect it sucked some moisture into the filter because the minder was pegged.

Did you change the filter? If not, you might consider doing so now.



-Ryan

 

[Bertram65]

Finally had a chance to hook up a spare boost guage with a new line today, a solid 24lbs, so guess I will have to pull the dash apart and figure out if it is the line or the guage, anoying, but at least it is not the engine.

 

[DJennings]

Before you pull it apart, pressure test the guage with a small tank or compressor. Set the compressor at 30 psi and then put a rubber tipped compressor air gun on the end of the boost bolt and see what the in cab guage reads. You'll know for sure if its off. It's just an expensive pressure guage.



You would think that lower altitude would create higher boost pressures, but I have experienced the reverse. I think it is because the higher density of the air at sea level creates more resistance for the turbo and it can't spool up as much at a given engine load.