Anyone ever hear of a back pressure problem - Diesel Forum

jelmore · 06-03-2005, 05:54 PM

My truck had a EGR valve replaced last month. The valve was stuck but the computer code showed a high back pressure. In fact the top hose blew off. After the EGR was replaced, the truck would have a turbo flutter every time you let off the throttle. It got to a point last night going up a small grade with the AC on, I was getting the flutter with a steady throttle. Also power was way down when trying to pass. Took to the dealer this morning. They replaced the VGT control valve. The truck seems to be better now but they say it still shows the high back pressure code. My exhaust is a Magnaflow 4" turbo back dual with no cat. So the only way there is a exhaust back pressure problem is if the muffer or the Y pipe is clogged. Any ever herd of this? We will pull the muffer off next week and look for any problems. But I just wonder if this is the problem or something else. Also when I say turbo flutter I am refering to the womp womp womp sound ( at least thats the best way to describe it)

jelmore · 06-03-2005, 05:57 PM

Also forgot when the EGR was replaced, the truck was flashed to the lastest and greatest.

mudguppy · 06-03-2005, 08:18 PM

so your dealer worked on your truck that is having exhaust back pressure and vgt problems, knows you have an aftermarket exhaust, and looks the other way!?!?!?! [img]/ubbthreads/images/graemlins/eek.gif[/img]

that's so cool. [img]/ubbthreads/images/graemlins/smirk.gif[/img]

why can't i have dealers like that where i'm from.... [img]/ubbthreads/images/graemlins/vulnerable.gif[/img]

bvit88 · 06-03-2005, 08:28 PM

I have the same problem. I took it to the dealer for a no boost issue, they replaced the ebp sensor, egr valve & vgt relay & another reflash. Now it is low on power & every time I let off the throttle it flutters through the intake & shows no codes. The tech said he would like to try a new turbo bit Ford will not authorize it. Any advice would be appreciated.

MoeB · 06-03-2005, 08:40 PM

Maybe the EBP sensor is giving false readings? There's at least one TSB about EBP sensors failing. The fix is replacement with updated unit.

jelmore · 06-03-2005, 09:16 PM

I don't know why the EBP sensor was not replaced when the EGR was. I thought both went together. And yes this dealer is very mod friendly.

Got_One_Too · 06-03-2005, 10:58 PM

You need to tell your service department that your truck has no power. You don't state what year your truck is or how many miles it has on it. I presume your truck is still under waranty. Tell your service department your truck would not top 30 mph getting on a busy freeway entrance ramp and that your vehicle has become unsafe. Now you have put the ball in Fords hands for your safety and well being.

You have a bad turbo charger. What I mean by bad is the vanes are sticking. Turbo flutter is not a nornmal sympton for our 6.0 trucks. I have read numerous comments on this web site that turbo flutter, fart, rubbing is a normal sound when in fact it is not. If your service department will not work with you seek out one that will. Your truck is broke [img]/ubbthreads/images/graemlins/frown.gif[/img]and should be repaired. Good Luck [img]/ubbthreads/images/graemlins/biggrin.gif[/img]

djshum · 06-03-2005, 11:19 PM

As stated, sounds like vanes stuck in turbo. This is probably the most common problem when having lack of power. Have them monitor ebp, mgp, vgtdc. If your ebp is reading 52psi and vgtdc is reading 15%, with overboost condition (usually will show 27-29psi boost) vanes are stuck, if the vgt did not fix it. You can remove plug on back of vgt housing and check plunger movement with a magnet. If the plunger doesn't move freely with pen magnet, vanes are stuck.