Really odd behavior on long drive. - page 1 - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• Really odd behavior on long drive. by Smokey Eddy on 12 Sep, 2009 16:33
• I haven't posted in quite some time because everything has been fine ... until this past week.
  It's been 13,000km since the rebuild and it was amazing, after it broke in in about 3,000km i was getting great mileage, between 40-50mpg depending on how often i wanted to show my friends what a boost gauge looked like reading 25 psi.
  
  But over this past week i've noticed the mileage is down about 15% maybe as much as 20%. I'd go 500km on 25 litres now i sometimes have to get another 25 after 350km...
  I noticed i had to top up the oil a while ago and just thought that was normal but now every time i check the stick its lower and lower and lower even with me topping it up. I'd added about 2 litres in a thousand kilometers now. I'm using 100% synthetic oil (moly lubro or what ever it's called).  it has moly in it.
  
  Yesterday, i went on a bit of a mini trip to these semi-alpine meadows in Manning Park (for you BC guys) and on the way there i was checking the egt and the oil+water temp because it's a pretty decent hill climb to get up there and everything was fine 800-1000 degrees on the slopes. but it felt like as the entirety of the engine got hot it started to lose significant power... i needed to gear down when i didn't normally, the egt's were at least 200 degrees hotter on the same gradient and they would hang for what i felt was a long time.  reach 1200 and just sit there even at very little throttle on the crest of the hill.
  
  I got to the top, no over heating or anything. the water temp gauge read 1 line hotter than the middle at the hottest reading. and i let it sit in the shade while we walked around the meadows. It's quite high up so the air was very cold but it was a sunny day. the air felt like 15-18C but if you sat still in the sun you would feel it. in the sun it felt like 36C and i guess the air would have been a little thinner. High enough that the trees are all short and sparse. It's technically called "sub-alpine".
  
  So anyways i would have normally blamed the behavior on perhaps thinner air or what ever but the curiosity is when i started it up 3 hours later to go home it had cooled down, not fully, but it wasn't at running temp but it smoked like a mother! on idle and on the throttle just plumes of blue horrid heart wrenching smoke. Really lurchy like the timing was way way way off. I was so concern i pulled over & popped the hood to see if the pump was loose... nope solid as a rock... not super hot or anything... the engine looked fine and SOUNDED very quiet. Much quieter than normal... I looked for leaking oil anywhere... nope clean as a whistle.
  
  I know that the cold side of the turbo had previously been letting oil into the intake but i read that was normal (to an extent)
  The tail pipes don't have raw oil dripping out of them (to indicate that the hot side of the turbo isn't blowing the oil out) but the exhaust around the inside is not dusty like i would have thought. it's sort of ... i dunno it's like a deposit on the bottom of the pipes im tempted to say clammy. Needless to say the oil im 99% sure is leaving the car in the exhaust in some manner.
  
  Thanks guys.
  I'm thinking oil getting into the cylinders through the cold side of the tubo. Thoughts? Solutions? (I really want to change the seals and what not on the turbo for this reason but im not sure where to get them and im also afraid of not being able to take the turbo apart of fear of shearing the bolt heads off)
• #1 by jtanguay on 13 Sep, 2009 06:06
• this is really out there, but with all the boost pressure you're throwing at this thing, maybe the rings have re-positioned themselves? IIRC, Dave (935racer) had that problem with his low budget sleeper.  all the rings had their gaps aligned so compression was down, and there was blow by.  i think he used total seal rings though, and that it was the total seal end gaps that were aligned with the ring end gaps. a leakdown/compression test should reveal if this is the case. the quieter running could be the reduced compression?
  
  have you taken the car out today? does it still act like it did yesterday?
• #2 by Smokey Eddy on 13 Sep, 2009 13:50
• I drove it last night and it didn't smoke anywhere NEAR as much but it's still rough after a start for quite some time. It was 30+ degrees yesterday so it's not like it was cold or anything. It starts perfectly, idles ok (a little smoky) but when i start to drive its really smoky (blue-ish white) and really lurches unless its WOT.
  I made triple sure when installing the pistons that the rings were all out from each other.
  Could the timing be too advanced?
• #3 by rallydiesel on 13 Sep, 2009 14:18
• Seems more like it's too retarded? Among other issues. The oil consumption is worrying. Are you sure the cam gear didn't move? From the grey smoke, gummy exhaust, hot EGT's, irregular revs it seems that it would point to not enough advance. What's the history on the pump? Of course, that doesn't explain the oil consumption at all.
• #4 by Smokey Eddy on 13 Sep, 2009 20:32
• Yes, the belt would have had to have slipped somewhere for the timing to retard because i had it extremely advanced.
  The history on the pump is ...
  
  i changed all the seals and brass washers and all that crap, i changed the shaft bearing, i solid shimmed the governor which never gave rpm problems when i did it. The idle is higher than it should be but i didn't think that would matter.
  The flue screw is turned all the way in. and my LDA pin is at a mediocre setting.
  
  
  
  Edit: I suppose i'll check all the timing marks tomorrow afternoon and at the same time i'll look into the intake to see if it's just pooling with oil.
• #5 by rallydiesel on 13 Sep, 2009 22:08
• After reading your first post again, I would have to agree with you that it's the turbo seals failing. Just be careful you don't have a runaway. What turbo are you running? I opened up a can of worms when I rebuilt my turbo. An exhaust stud broke off and I ended up having to find a turbine housing to replace it after a stud extractor broke off in the housing  . But then you really can't drive around with a blown turbo for long without tempting fate.
  
  I got a really good rebuild kit from http://www.adpdistributors.com/turbochargers.html.
• #6 by Smokey Eddy on 13 Sep, 2009 22:33
• I have a Garett T3
  
  wow that's pretty close to me. Perhaps i should drop in there.
• #7 by Smokey Eddy on 26 Sep, 2009 22:51
• Anyone have any tips, walk throughs, DIY's for taking the turbo apart to do a rebuild kit?
  
  Thank you,
  
  Ed
• #8 by rabbitman on 27 Sep, 2009 00:01
• You have an intercooler don't you? Maybe it's puddling up with oil from the turbo.
  
  I think the engine will quiet down when it has to burn oil. Hope you can get it sorted......I hate it when stuff burns oil.
• #9 by Smokey Eddy on 27 Sep, 2009 01:24
• I don't have the IC installed yet, but i bought one.
  
  edit: and yes im assuming it would puddle with oil.
• #10 by Doug on 30 Sep, 2009 15:13
• Is your egt post or pre turbo? That will determine just how much heat has been developed in the combustion chamber. After reading and thinking about this I really think that you have overheated the combustion chamber leading to a failure of the rings by annealing due to the excessive boost pressure and heat. Note that it was the long heat event of climbing the grade that caused the symptoms of oil visibly burning. I seriously doubt that turbo seals would fail that dramatically. When rings on the piston fail they allow extra oil which behaves like fuel into the combusion chamber which drives the egt higher again as fuel generates heat. Rings on most pistons will rotate in the lands. They will not leak appreciably even if the gaps are aligned at some point. Only 2 cycle engines with port induction use ring land pins to prevent rings from rotating and getting caught in the ports at some point. 25 psi boost must be about 3 times the standard boost that the engineered factory turbo generates.
• #11 by Smokey Eddy on 01 Oct, 2009 00:48
• That is a VERY good theory. very very very good.
  Hmmm. If it wasn't my dd i'd for sure take the pistons out and have a looksie.
  The amount of oil coming out of the turbo is extreme now though.
  
  My egt probe is PRE turbo. at the union of the runners.
• #12 by Doug on 01 Oct, 2009 05:42
• What does the blowby situation look like? Is the crankcase ventilation hose plugged into the intake manifold? If it is, disconnect it to atmosphere driving it for a while to see if the turbo looks less wet with oil. Remember that oil looks wet for a good long time. If there is significant pressure on the vent hose I'll bet that the rings are not working. If so it may be a simple glaze over the walls of the cylinder caused by extreme boost pressure driving oil past the rings cooking it on the walls. Your engine is still quite new with only 13K on it. Was the rebuild a bore job fitted with new pistons? If only a honing with new rings I will guarantee that it will take longer for the rings to conform to the previous wear of the cylinder. With synthetic oil it may never happen!
• #13 by Smokey Eddy on 01 Oct, 2009 13:07
• Quote from: libbybapa on 01 Oct, 2009 07:33

  Boost does not cause increased heat, fuel does.  That being said, Eddy, if you are not intercooled, there is very little point in boost levels above 15 psi or so.  Above that point, unless you are getting rid of the heat of compressing the air, you're not getting much gain at all.  Really just blowing hot air...  
  
  Provided your exhaust valves are not leaking, if your EGTs never got above 1200°F pre-turbine and your engine did not overheat I doubt your rings got hurt.
  
  Also, boost will not push past rings, it will create higher cylinder pressures and push the rings more firmly against the cylinder walls.
  
  Really, if broken in correctly, the rings should mostly seat within the first hour and fully seat within 1,000 miles.  That said, I seem to recall a fair amount of idling after the initial assembly...  
  

  Yes i know boost over those numbers is pointless that's why i don't ever really go over 10 psi. my intercooler will be in my garage in 3 days now though.
  I only idled it to get coolant in the rad. After that i drove it like a normal car.
  I pulled the hose off the breather on the cam cover and it wasn't excessive by any means it was totally clear. Just warm on my hand. I'll try cleaning the turbo up good and run it with the breather off.
  
  I sway away from break in not being done properly because this is a new issue... not like it was like the rings never seated and always let oil passed. For about 7,000km i didn't have to add a drop of oil. thats when i changed it to synth.
• #14 by Smokey Eddy on 29 Oct, 2009 14:48
• So i tore everything apart last night.
  Drove it into the garage
  Set up my work space
  And got crackin'
  
  I shaved all the gasket material and soot off the surface here with a razor blade. Everything looked really nice. The soot came off very uniformly EXCEPT for 1 of the cylinders - which was very gooey... didn't seem very "right". I quickly learned why...
  The valve stem seal for the intake valve on this cylinder had come free and was right up in the springs. I guess I hadn't pressed it on hard enough? These came from prothe so I'm weary of the quality.
  
  This still doesn't explain my rough cold starts (which aren't even that cold...) and the rings arrived just over the border today so I just gotta run across the border and pick them up.
  It's funny, what took me WEEKS to accomplish last time took me about 4 hours last night after dinner. And I took my time.