Boost leak? - Ford Powerstroke Diesel Forum
Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 07-30-2012, 05:17 PM
Compression Ignition Addict
 

Join Date: Jun 2012
Location: Denver
Posts: 323
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Boost leak?

I am thinking that I have a boost leak. I typically am driving on the DP 80hp tune and have the mods in my signature. The BD Turbo is a stock replacement, or so I was told. When driving around with my foot on the gas cruising I am sitting at 1-3psi of boost at 1700 rpm. When I am on it at 2500rpm+ I don't see more than 10psi boost until I hit overdrive, then I haven't seen it about 20psi, and I was over 100mph at that point. I have been searching the forums and it sounds like I am low on boost, what do you guys think. I also keep reading about a "boost leak test" but I haven't been able to find a forum on how to do the leak test. Can someone point me in the right direction or tell me how to do a leak test? Also, what else should I be looking at/for?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 07-31-2012, 04:19 AM
Banned
 

Join Date: Sep 2008
Location: Fort Bragg, NC/Buff, NY/Midlothian, VA
Posts: 5,630
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Could be. what did you used to boost? What does the tune call for? To me that sounds low.. super duty's are more like 25-26psi I though.
Reply With Quote Quick reply to this message
  #3  
Old 07-31-2012, 02:39 PM
Compression Ignition Addict
 

Join Date: Jul 2012
Location: Ventura, CA
Posts: 180
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Try a WOT run and see how high you get. You should get to about 26psi on a tune with a stock turbo.

As far as the leak tester it's pretty easy. Just get a 4" pipe cap, an air hose fitting, and a pressure gauge. Drill into the top of the cap and screw in the pressure gauge. Most will tap themselves and it doesnt have to be a commercial grade job. Just use the threads on the gauge to tap it. Same thing with the hose fitting. Put the cap in the intake boot and clamp her down. You dont need to pressurize it to 26psi, 10psi will do. For this you will need a regulator on the compressor or in line. Keep the flow on as you will probably lose pressure just naturally through the tail pipe.

Now just go around with a spray bottle with soapy water and look for bubbles.
Reply With Quote Quick reply to this message
  #4  
Old 07-31-2012, 03:14 PM
Banned
 

Join Date: Sep 2008
Location: Fort Bragg, NC/Buff, NY/Midlothian, VA
Posts: 5,630
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
i disagree on not tesing to 25psi... you typically test 5-10psi over your max-boost, to account for overboost and spikes. If your turbo is spooling up to 25psi and a charge pipe pops off sending it to 30, even 40psi, kiss that shaft goodbye.


Also, you should be able to build boost up to 'x' psi, turn the compressor off, and not lose any boost. You should be able to detect boost leaks by boost dropping and it hissing out of the leak.
Reply With Quote Quick reply to this message
  #5  
Old 07-31-2012, 06:40 PM
Compression Ignition Addict
 

Join Date: Jul 2012
Location: Ventura, CA
Posts: 180
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Quote:
Originally Posted by 85_305 View Post
i disagree on not tesing to 25psi... you typically test 5-10psi over your max-boost, to account for overboost and spikes. If your turbo is spooling up to 25psi and a charge pipe pops off sending it to 30, even 40psi, kiss that shaft goodbye.
Um, no.

A leak will be present at ANY boost level, not just over boost. If you want to test how much pressure the system can hold then you want to do as you said. But thats not what the OP wants to test. The OP wants to see if the system can hold pressure, not how much. Even at 1 psi the air will leak if he has a leak, there just wont be much air to help find the leak. 10 psi is a safe level where if the tester slips out it will wont have much momentum. At 30 psi its more like a ballistic object.
Reply With Quote Quick reply to this message
  #6  
Old 08-01-2012, 04:14 AM
Banned
 

Join Date: Sep 2008
Location: Fort Bragg, NC/Buff, NY/Midlothian, VA
Posts: 5,630
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Quote:
Originally Posted by AOx4 View Post
Um, no.

A leak will be present at ANY boost level, not just over boost. If you want to test how much pressure the system can hold then you want to do as you said. But thats not what the OP wants to test. The OP wants to see if the system can hold pressure, not how much. Even at 1 psi the air will leak if he has a leak, there just wont be much air to help find the leak. 10 psi is a safe level where if the tester slips out it will wont have much momentum. At 30 psi its more like a ballistic object.
If your gonna be an *******, at least be a correct *******. Because your wrong.

1psi of boost is nothing... thats like sticking your mouth to the IC piping and blowing into it. If you pulled your IC piping and blew into it, do you really think your body would have enough pressure to pressurize the system?

I'll help you out. No, your body wont even phase the gargantuan IC setup.

You need to pressurize to the PSI that truck typically runs at. 32psi is going to have a lot more force behind it than say, 1psi or 10psi. Thats a huge difference in pressure. When your turbo is pushing max boost and your driving down the road, the IC lines are moving, radiator/ic moving, the motor is torqueing etc... which can create boost leaks. You have to do everything you can do to simulate driving down the road to find the stubborn boost leaks.

For instance. My TDI I boost about 30psi. If I juice the IC up to 30psi w/ my leak down setup, nothing will leak. Now, simulating driving down the road, shaking the IC lines and the IC, all of a sudden I have a boost leak popping up that ONLY shows when the motor is tweaking and allowing the boost leak to show.

When you test at pressures this high, put a very heavy rag/towel over the boost fitting incase it pops off.

And lastly, if your IC is sealed off as well as it should be, there should be very little to no boost leaking out w/ the compressor shut off. The gauge should barely move on the decrease when sitting idle.
Reply With Quote Quick reply to this message
  #7  
Old 08-01-2012, 11:48 AM
Member
 

Join Date: Mar 2012
Location: Valley Springs, SD
Posts: 33
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
The early 99's have a smaller turbo than later 99-03 7.3L's. They dont run much more than 16-18psi from the factory.
Reply With Quote Quick reply to this message
  #8  
Old 08-01-2012, 12:01 PM
Banned
 

Join Date: Sep 2008
Location: Fort Bragg, NC/Buff, NY/Midlothian, VA
Posts: 5,630
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
assuming he's on stock tuning, and not boosting anymore than that, I'd still add 4psi on... so I'd test to 20psi.
Reply With Quote Quick reply to this message
  #9  
Old 08-01-2012, 06:06 PM
Compression Ignition Addict
 

Join Date: Jun 2012
Location: Denver
Posts: 323
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Thanks for all the info and opinion. Ill be doing a leak test this weekend and cleaning all my IC fittings. Considering doing a CCV mod too, depending on how much oil I find.

Sent from my DROID RAZR using AutoGuide.Com Free App
Reply With Quote Quick reply to this message
  #10  
Old 08-03-2012, 10:41 AM
Compression Ignition Addict
 

Join Date: Mar 2011
Location: Lowville, New York. Studying Mechanical Eng. @ Suny Canton
Posts: 586
Thanks: 6
Thanked 6 Times in 6 Posts
Feedback Score: 0 reviews
you could have a leak in your up pipes. I had lower bost then I was suppose to and went looking and found a hole in the up-pipes.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 09:30 AM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors