blown99 Posted April 1, 2015 Share Posted April 1, 2015 2005 F-350 5.4 3v. Came in with codes p0340, p0300, p0303 p0304 Customer had it elsewhere and told him the phasers were bad due to the p0340 code The phaser is not making any noise until it is up to temp. Cylinder balance shows a cyl 1 and 5 a bit on the lower side. Relative compression shows #3,4 down around 15%. Cranking is uneven. My question is, can a cam phaser cause the compression to be low in a cylinder? I have yet to check base engine oil pressure. Engine has 95k on it, truck is well worked. Quote Link to comment Share on other sites More sharing options...
8WA Sman Posted April 2, 2015 Share Posted April 2, 2015 I would check base oil pressure then go from there. I can't think of a way cam phasers would be the cause of uneven cranking. Quote Link to comment Share on other sites More sharing options...
jw33 Posted April 2, 2015 Share Posted April 2, 2015 Usually if a phaser is causing timing issues it affects whole bank not just 2 cylinders Quote Link to comment Share on other sites More sharing options...
forddieseldoctor Posted April 2, 2015 Share Posted April 2, 2015 I would check base oil pressure then go from there. I can't think of a way cam phasers would be the cause of uneven cranking. I've seen it. But the root cause was low oil pressure. The oil pressure dropped while the pin was unlocked and it was unable to lock the pin. Truck ran horrible and when I went to restart it you could hear that the compression wasn't right. Quote Link to comment Share on other sites More sharing options...
blown99 Posted April 5, 2015 Author Share Posted April 5, 2015 Well, the base oil pressure was low. Down to 20 psi at 150 degree oil temp. You can here the rod bearings clattering around just after start up. Quote Link to comment Share on other sites More sharing options...
jw33 Posted April 5, 2015 Share Posted April 5, 2015 Thought spec was 15 psi hot Quote Link to comment Share on other sites More sharing options...
forddieseldoctor Posted April 5, 2015 Share Posted April 5, 2015 Spec is 15. Quote Link to comment Share on other sites More sharing options...
sneakypete Posted April 5, 2015 Share Posted April 5, 2015 but you need at least 25 psi for proper vct operation. Quote Link to comment Share on other sites More sharing options...
jw33 Posted April 5, 2015 Share Posted April 5, 2015 Can't remember part number but thought I read the new vct solenoids were made to operate at 15 psi that's why spec was lowered to 15 Quote Link to comment Share on other sites More sharing options...
sneakypete Posted April 6, 2015 Share Posted April 6, 2015 that could be. I haven't heard that. very interesting. Quote Link to comment Share on other sites More sharing options...
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