Extremely low boost pressure
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Junior User
Joined: Jan 2008
Posts: 61
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Extremely low boost pressure
I have a E99 F250 with a 4in turbo back exhaust, 6637 mod, quadzilla gauges and a DP Tuner. I have never seen more the 12 lbs of boost out of this truck since I have owned it but recently after towing a few more trailers and bigger ones then i used to, I noticed how high my EGT's were getting (around 1200-1300 at half throttle or less and the same at 3/4 throttle unloaded). so I made a boost leak tester and checked it with 22 psi and found a pretty good size leak in one of the boots. so i took it apart and it turns out that one of the welds or casting seams from ford was so tall it would not let the boot seal, so i filed it down smooth, hooked everything back up and tested again. this time no leaks, so that was good. Then i took it for a test drive and still cannot get anymore than 10 psi at WOT in 140hp tune.
I looked for soot on the fire wall but didnt really see any, turbo is tight with no play in the shaft. So now i just dont know where to look for what may be causing this. Any suggestion or help would be appreciated.
Thanks
I looked for soot on the fire wall but didnt really see any, turbo is tight with no play in the shaft. So now i just dont know where to look for what may be causing this. Any suggestion or help would be appreciated.
Thanks
you can't fix stupid!
Joined: Mar 2008
Posts: 1,906
Likes: 2
even with leaking uppies you should see more boost than that....did you get the spyder lined up correctly? i be you have a serious leak in your uppies though....can you reach up from underneath and move them around with your hand? when mine went south as soon as i unbolted them from the manifolds the up pipes literally fell out onto the floor....the crush donuts up top i think were totally gone....i dont know how much you want to spend but a set of bellowed uppies are very nice and will ensure you will have no more up pipe leaks...since youre running an e99 youre gonna hate the cost of them....
Postmaster
Joined: Apr 2012
Posts: 2,613
Likes: 8
From: North Georgia
Both my upps are leaking at the collector and all i see WOT pulling a hill is 10psi
No other leaks in my system.
6637 air filter
4" turbo back
400k miles stock everything else.
About to dump about 4k into my motor so i can make that cool mill.
Gonna do injectors, frx, t500 hpop, dp f6 this round...
And the bellowed internationals..
Hoping i will see better boost numbers with the upgrades...
Xtof
No other leaks in my system.
6637 air filter
4" turbo back
400k miles stock everything else.
About to dump about 4k into my motor so i can make that cool mill.
Gonna do injectors, frx, t500 hpop, dp f6 this round...
And the bellowed internationals..
Hoping i will see better boost numbers with the upgrades...
Xtof
Post Fiend
Joined: May 2009
Posts: 5,470
Likes: 3
From: Pea Ridge, AR
Don't dread the solution, decide what you want to do with the truck, then consider the options, stock pipes new from Ford aren't that expensive then throw some new Chevy donuts, and be happy for another 200k IMO. Or pull the pipes, use a pipe expander to slightly flare the pipes, and new donuts, and be done that way too.
Hotshot
Joined: Jan 2011
Posts: 18,849
Likes: 179
From: Puget Sound
I had low boost and the leaks were everywhere. That sucker spouted serious soot and the decibles at daybreak were definitely disruptive. New manifolds (notice the "s" there), new ups, and new collector were the only reliable cure for my issues - so it can always be worse than just ups.
I feel I can now speak with some experience to the matters of exhaust leaks. The driver-side manifold is usually a suspect, right next the outlet to the up-pipe. When the truck is running, but not yet hot, feel around manifolds and listen. I was on a creeper behind the wheel to get the rear and I reach through the tire well (wheels turned hard) to reach further forward. I could hear the leak and feel the heated exhaust blowing on my hand between the bottom-rear of the manifold and the engine block - both driver side and passenger side. I don't do broken manifold bolts, so I scheduled the repair with a mechanic. Before I took it in, I shot all the manifold bolts with PB blaster 2-3 times a day for 4 days. The mechanic said he had no issues with the bolts and the bill reflected this.
When I got the truck back, I "accidentally" spun the wheels on a hard accel out of the driveway - much to my (and the neighbor's) surprise. Oooo... power-er, smokeless-er and quiter. Cool. Boost could eek out 22 PSI in stock. Ah... "Powerstroke"... got it.
I feel I can now speak with some experience to the matters of exhaust leaks. The driver-side manifold is usually a suspect, right next the outlet to the up-pipe. When the truck is running, but not yet hot, feel around manifolds and listen. I was on a creeper behind the wheel to get the rear and I reach through the tire well (wheels turned hard) to reach further forward. I could hear the leak and feel the heated exhaust blowing on my hand between the bottom-rear of the manifold and the engine block - both driver side and passenger side. I don't do broken manifold bolts, so I scheduled the repair with a mechanic. Before I took it in, I shot all the manifold bolts with PB blaster 2-3 times a day for 4 days. The mechanic said he had no issues with the bolts and the bill reflected this.
When I got the truck back, I "accidentally" spun the wheels on a hard accel out of the driveway - much to my (and the neighbor's) surprise. Oooo... power-er, smokeless-er and quiter. Cool. Boost could eek out 22 PSI in stock. Ah... "Powerstroke"... got it.
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Elder User
Joined: Jul 2008
Posts: 569
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From: Buckenderra
have you checked the intercooler, the stock coolers run plastic tanks with orings to seal to the header just like your radiator. a blown oring or cracked tank would loose boost easily and not easy to spot either being partly hidden...
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Of the next Riffraff East
Joined: Oct 2004
Posts: 8,679
Likes: 2
From: Concord NC
Make sure waste gate is working right, then check seating at spyder and turbo. Will look seated until everything heats up and twist just enough for them to seperate a little and loose boost. Jim, Megawatt had that happen to him after a turbo swap a few years back. Took a while to find it as it looked and felt good. Mine had a high pitched whistle when I put mine back and didn't get a good seat on the two. Not even sure it would show on a boost leak test without turbo spinning and causing it to open up.
Senior User
Joined: Jul 2006
Posts: 395
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From: New Hampton, IA
I found boost leaks in places I was not expecting when I did my boost leak check, I just found them by accident. The AIH threads were leaking and I have a big leak at the clamp from the turbo compressor housing to elbow. When you check for leaks check EVERY part from the turbo (including the turbo) to the intake. You might be surprised where you find leaks.
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Junior User
Joined: Jan 2008
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well after looking around on it today i found a couple more leaks in the boots so im ordering a boot kit from riffraff, im also ordering the 99.5 3" plenums, figure while im changing boots may as well upgrade those. the up pipes are tight and after crawling around and inspecting the manifolds and up pipes i cannot find any soot. i noticed the ends on the green and red vacuum lines are dry and cracked so i will be replacing those, even though the red one is unhooked from the wastegate. so im hoping that after replacing the boots it may correct some of the issue but if it doesnt at least i know they are new and good to go. i will post any changes as soon as they get here and i get them on.
Thanks for all the input and suggestions.
Thanks for all the input and suggestions.
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