RyanG Posted February 2, 2015 Share Posted February 2, 2015 truck came in with p252f, checked oil, slightly overfull like they all are. checked high pressure pump leaking from oil pan, ran high pressure pump at 24000 with raised rpm, no oil level rise. coolant level good. checked for excessive oil in cac, no issues. noticed excessive crankcase pressure from oil fill, ran test, showing high 20,s to 30 in h20. fuel trims ok except cylinder 2, creeping up to +15 when warming up. relative compression shows cylinder 2 down sometimes as much as 6%. ran manual compression test, all cylinders bank 2 around 360, cylinders on bank 1 are 380 and 390. tech line is telling me turbos for crankcase pressure issue possibly pressurizing crankcase, checked turbos don't have excessive play, don't see oil. im stumped. have not done in depth diag on these engines except for the usual catastrophic failures, radiators, front covers etc. any insight would be appreciated. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted February 2, 2015 Share Posted February 2, 2015 I catch those high pressure turbos leaking all the time from the compressor seal. You might not have oil in the intercooler yet but the compressor outlet will be coated in a thick black sludge. If that seal is bad it could easily be the source of your crankcase pressure. Quote Link to comment Share on other sites More sharing options...
RyanG Posted February 2, 2015 Author Share Posted February 2, 2015 thanks for the input. did notice sludge build up, I have seen worse at high pressure outlet. another question I have is this truck has a tuner and dpf delete, ran relative compression, cyl. 2 is showing down 4%. ran manual compression test again at operating temp, all cylinders bank 2 at 365 psi, all bank 1 cylinders at 380-385 psi. pressure is within 25 psi max separation spec. relative compression test on 6.4 not reliable? like I said im getting +12 to +13 on stft on cyl. 2 with no contribution codes. throw in an injector? possibly the cause of p252f? Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted February 3, 2015 Share Posted February 3, 2015 Now that you mention it I have heard of performance tunes causing that code with the new strategy but I'd have to dig into it a little further to know anything more. You may want to have your customer e-mail or call their tuner and see if they know anything. The relative compression and short fuel trims are concerning to me, especially given the nature of the #2 cylinder. 9 out of 10 times I see a problem with #2 it is shortblock time. The other 1 time I switched an injector with #4 and the miss actually moved. If you have some time and diag hasn't already beat you to death I'd switch that injector with another cylinder and clear your HPFP adaptive tables. Check the rockers and valve train movement while your in there. Quote Link to comment Share on other sites More sharing options...
amailloux Posted February 3, 2015 Share Posted February 3, 2015 I would pop the left cover and take a fuel sample from the rail and check it closely for debris. Swap 2 and 4 like Matt said and recheck trim. Sounds like it may be short block time, and maybe a fuel system. The last couple trucks in with trims creeping up, I found glitter in the rails. One had 8200 hours and I did the relative compression hot, cold, and anywhere in between and it was always zeros. checked manual compression and had 350 at 5200 feet. Anytime I see 2 or 8 down on relative compression, with excessive crankcase pressure It needs the head to come off. Quote Link to comment Share on other sites More sharing options...
RyanG Posted February 3, 2015 Author Share Posted February 3, 2015 well guys ran manual compression test one last time cyl.1 - 400 cyl.2 - 360 cyl.3 - 380 cyl.4 - 380 cyl.5 - 360 cyl.6 - 380 cyl.7 - 380 cyl.8 - 365 im gonna pull valve covers and look at rockers. this truck has a fairly good service history up until a year ago, came in with napa oil filter. wondering if I have polished cylinder walls. I'll let everyone know what I find. when you guys saw fuel trims creeping up on 2, what was the outcome when you pulled the head? polished cylinder walls, burnt rings? this may be a stupid question, on the crankcase pressure test, noticed boost gauge on the cluster was at 20 psi. is it normal to see boost that high with engine unloaded? ive never paid attention. like I said have not done much 6.4 in depth diag. guess Its gonna happen now that these pigs are getting older. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted February 3, 2015 Share Posted February 3, 2015 I don't know what you're controlling during the crankcase pressure test, but I can build about 23-24psi boost in the bay on a good 6.4 by using IDS to run up RPM and closing the VGT most of the way. 1 Quote Link to comment Share on other sites More sharing options...
RyanG Posted February 3, 2015 Author Share Posted February 3, 2015 that what I don't understand, I wasn't controlling vgt or with ids, I just revved the engine to 3000 and watched the gauge Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted February 3, 2015 Share Posted February 3, 2015 The majority of what I see has polished cylinder walls. A good 3-4" bore micrometer will be your friend when looking at a 6.4. Taper and out of round specs are only .002-.003" if I remember correctly. I never have any problems seeing those out of spec. Quote Link to comment Share on other sites More sharing options...
RyanG Posted February 7, 2015 Author Share Posted February 7, 2015 pulled the cac tube off of the high pressure turbo, reran crankcase pressure test and it passes. pulling heads per ford, I will let everybody know what I find. Quote Link to comment Share on other sites More sharing options...
RyanG Posted February 20, 2015 Author Share Posted February 20, 2015 Well tore the head off, we have polished cylinder walls. took a fuel sample from cylinder 2 injector pipe, fuel system has metal particles and the rockers on bank 2 have worn out tips, I would say this one is done. thanks for all the input guys. Quote Link to comment Share on other sites More sharing options...
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