LR Mike Posted January 11, 2007 Share Posted January 11, 2007 Good morning, all! I know I've read this on here somewhere before, but I can't find it. I have an 03 F550, 77K miles. It won't boost 90% of the time, and the VGT LRN is NO. Once, I hammered it hard, it blew black smoke, no power, then grabbed and had boost like normal. Operated OK for less than 5 minutes, then back to nothing. Checked and tried to clean the turbo - very oily, and rusted under the vanes on the housing - new turbo installed (with drain tube). Rechecked EGR - clean and clear (less than 8K miles old) light deposits in intake, but nothing blocked. I tried the EGR test on IDS, but it fails for low MAP every time (under 15psi KOER). The MAP and BARO match. Substituted anoth MAP - no change. T fitted a gauge to MAP line, and it indicated exactly what the PID displays - a vacuum idle! The fitting is clear, and I can feel boost at the elbow - even the CAC tubes move and the boots swell when RPM pushed up! Now I'm at a loss - I'm thinking intake plugged, but where? Any ideas or am I missing something stupid? /forums/images/%%GRAEMLIN_URL%%/crazy.gif Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted January 11, 2007 Share Posted January 11, 2007 EGR throttle plate? Quote Link to comment Share on other sites More sharing options...
LR Mike Posted January 11, 2007 Author Share Posted January 11, 2007 Good idea, I already checked an it has a 'fake' - just an open hole! Maybe nothing, but the truck had a dead cluster when it got here (not a complaint, of course) blown fuse. replaced it to clear all the DTC's and try to get the VGT to learn. P0603 when it got here, but I don't remember seeing it since. Quote Link to comment Share on other sites More sharing options...
ktmlew Posted January 11, 2007 Share Posted January 11, 2007 IAT2 fouled with crap? Need more PID info... Quote Link to comment Share on other sites More sharing options...
blown99 Posted January 11, 2007 Share Posted January 11, 2007 What are you ford guys calling an EGR throttle plate?? Quote Link to comment Share on other sites More sharing options...
m-mathus Posted January 11, 2007 Share Posted January 11, 2007 it has a throttle plate to lower the pressure in the intake to help egr gasses to flow. the pcm commands it closed when needed. i'm guessing that this is a ford only option and not used on navistar trucks. Quote Link to comment Share on other sites More sharing options...
Alex Bruene Posted January 12, 2007 Share Posted January 12, 2007 This may be a stupid question, but have you removed the MGP fitting from the intake and checked/cleaned it? How about trying to perform a KAM reset and VGT relearn? Quote Link to comment Share on other sites More sharing options...
Alex Bruene Posted January 12, 2007 Share Posted January 12, 2007 Hah... now that I've actually taken the time to read your posts, I see you have done all that... I figured I'd post that I noticed how stupid my question actually was, instead of deleting that previous post... sorry. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted January 12, 2007 Share Posted January 12, 2007 T fitted a gauge to MAP line, and it indicated exactly what the PID displays - a vacuum idle! This is the part of your post that should get the attention. I vaguely recall chasing my tail on something similar to this but I do remember that at idle a small vacuum reading CAN occur due to the restriction of the air filter and the charge air cooler. A high vacuum reading in the manifold on a diesel engine can only mean that there is a restriction somewhere in the intake system. You didn't mention what the reading was but if it's high I would be inspecting the entire air intake system from the air inlet before the air filter all the way to the manifold inlet. Then, If there is no restriction found I would remove the charge air cooler and turn it on it's side to see if it is loaded with oil or caked with dirt. Oil is easy to detect because you can collect it into a clean drain pan. To see blocked passages from dirt or debris (you never know) you will need a good light and a mirror or a boreoscope. Before you discredit that, remember that you stated the turbo was "very oily." Remember the 2003 trucks with the injectors that leaked fuel into the oil and damaged the oil seals in the turbo? Read this! Quote Link to comment Share on other sites More sharing options...
LR Mike Posted January 12, 2007 Author Share Posted January 12, 2007 OK, baro and MAP at KOEO indicate 14.9 PSI, KOER at idle MAP is 14.5 or so. Maybe I'm reading too much into this part, but with this figure the truck won't complete the IDS EGR test - it needs to see a little of 15 to run the test. I made an adaptor to measure pressure at the intake to cold side tube elbow, only about 1/2 lb of boost at 1200 RPM, VGT 85%. We pulled the CAC cooler this AM and inspected - not restricted, no oil no unseen leaks, so back to the board! I'm pulling hte down pipe now to retest, not sure what I'll see.... As for the injectors, oil level is correct. Ever so slightly over the full mark, but we use bulk oil here and the lube dudes havea tendancy to not recheck after they fill, so not surpprised. Maybe we'll end up there, but the turbo I took off still spun freely, just a lot of oil in the exhaust side. I'll check the IAT2, but not sure how this will effect the boost? Also, fuel filters were replaced - haven't check fuel pressure yet, but would this give me the low boost? Quote Link to comment Share on other sites More sharing options...
ktmlew Posted January 12, 2007 Share Posted January 12, 2007 Review this thread. Maybe something here will jump out at you? http://www.forddoctorsdts.com/forums/ubbthreads.php?ubb=showflat&Number=3436&page=1#Post3436 Quote Link to comment Share on other sites More sharing options...
LR Mike Posted January 12, 2007 Author Share Posted January 12, 2007 That was one of threads I was looking for! Thanks! I checked everything over top to bottom again earlier, from under the truck there is soot evident on the left head, so I'm in the process of removing the y-pipe now. Fingers crossed! Quote Link to comment Share on other sites More sharing options...
LR Mike Posted January 12, 2007 Author Share Posted January 12, 2007 UNREAL! A small (and I mean small) hole in the Y-pipe! Installed a new Y-pipe, let it warm up, KOEO and make sure no DTC's, and began to learn right away! Test drove and boost all day long! It passes the EGR test now, too - 15.5 on the MAP during the idle section of the test vs 14.5-14.7 before. /forums/images/%%GRAEMLIN_URL%%/banghead.gif /forums/images/%%GRAEMLIN_URL%%/laugh.gif /forums/images/%%GRAEMLIN_URL%%/crybaby2.gif Think I'll head home and /forums/images/%%GRAEMLIN_URL%%/drinkingdude.gif Thanks for all the help guys - I'll see if I can get a pic of it on Monday. Quote Link to comment Share on other sites More sharing options...
DamageINC Posted January 13, 2007 Share Posted January 13, 2007 Wow - I'm glad you got it all figured out. I would have loved to suggest something but everyone else here already beat me to any ideas I'd had, lol. Either way, it'd be interesting to see a pic of this. How big would you say the hole was???? Dave Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted January 13, 2007 Share Posted January 13, 2007 It does not take much of a hole at all to cause these engines to go into a tizzy. Usually the VGT Learn will occur but the check engine light will soon come on with a P132B but you never got that far. I am interested in how a tiny leak in the exhaust system can negatively affect the MAP reading? This was a good one and I will remember the correlation between exhaust and MAP readings even though I don't quite understand it. /forums/images/%%GRAEMLIN_URL%%/crazy.gif Quote Link to comment Share on other sites More sharing options...
No Wiper Blades Posted January 13, 2007 Share Posted January 13, 2007 No air out will = no air in. Exhaust restricted? Quote Link to comment Share on other sites More sharing options...
DamageINC Posted January 13, 2007 Share Posted January 13, 2007 I am interested in how a tiny leak in the exhaust system can negatively affect the MAP reading? This is exactly what's going through my head too, I don't quite see how a small exhaust LEAK is going to bring manifold pressures DOWN. The next time I encounter any small pre-turbo exhaust leaks, I'll check my MAP at idle just for grins. Dave Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted January 13, 2007 Share Posted January 13, 2007 One thing that backs this up in theory is that the diagnostics for the MAP sensor and code P132B include exhaust leaks as a possible cause. Hmmmm....perhaps what little air the turbo moves at idle is enough to make up for pressure drops through the air filter and the charge air cooler? So a leak in the exhaust will cause less energy to drive the turbo... nah! This also effects backpressure. A small leak? I'm really reaching for it, ain't I? /forums/images/%%GRAEMLIN_URL%%/rofl.gif Quote Link to comment Share on other sites More sharing options...
DamageINC Posted January 13, 2007 Share Posted January 13, 2007 See, I thought that maybe by the impeller spinning too slow, it could possibly act like an intake restriction and *maybe* create a low MAP reading at idle. But, the compressor side of the turbo, even NOT spinning, really is still a relatively free-flowing design and it really would be surprising to me if that was the actual cause of the MAP readings. Perhaps a slowly rotating impeller is actually worse than a stationary one??? Dave Quote Link to comment Share on other sites More sharing options...
LR Mike Posted January 15, 2007 Author Share Posted January 15, 2007 Here's the pic of the leak. This sooted up the back of the head and little else (until I looked close after I found it, of course) The basic idle reading on the MAP didn't actually change that much, BUT the EGR test now showed a full 1PSI increase, and the difference at idle was enough to allow the VGT to learn properly! I believe the fact that the VGT was unlearned had some effect on the EGR test, though I can't prove it. I can't see how this caused the turbo to slow that much, but maybe Anyway - on to the next headache! - next up another LCF..... Thanks again everyone - awesome response! Quote Link to comment Share on other sites More sharing options...
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