smoke at startup

[bobc]

Hey guys, funny (ok not funny 2me) way to introduce myself as a new guy here...

 

I enjoy this forum and have been lurkin and reading thru the archives regarding all sorts of topics.   Unfortuntely now I have a problem that just popped up and figured I'd toss it to the collective.

 

6 weeks ago I bought a 2001 Silverado LT 1500 2WD w/5.3 motor.  I must say the new truck feels more like a Cadillac in comparison to my old Ford truck and I've been really enjoying it... until today at lunch, when I started the truck and found myself engulfed in a cloud of oil smoke.    

 

Truck has 44k on it, I don't have an extended warranty.  Now I know why the guy sold the truck.

 

Anyone have any similar experiences or know of any TSB's?  For that matter has anyone had any luck getting TSBs honored out of Factory Warranty?  

 

Thanks in advance.  First round is on me!  

 

Bob

[RyanbabZ71]

My suggestion

 

Change the pcv valve.  Cost is less than $3 and this is supposed to be the fix to smokey startups (this was common on the 01s i believe so they updated the pcv valve)

 

Easy to change also takes less than 5 min (after you find it)

 

If that doesnt work then try the dealer

[RyanbabZ71]

I also had oil consumption problems early on with my 5.3. There is a TSB (technical Service Bulletin) number 01-06-01-029 that deals with higher than expected oil consumption. It has you replace the PCV with a smaller "fixed orfice" PCV. I did this on my truck at about 1500 miles, after the low oil light came on after a trip. It was 2 quarts low, but, I never checked it from factory to see if it was full. The truck did smoke on start up before I changed the PCV, now I dont notice it as much. The truck now has 6000 miles on it with no noticible oil consumption. Not sure if it was the PCV or just engine break-in that cured it. The PCV was $2 at the dealer, so it was easier for me to buy it myself and install it rather than take the truck in and have them do the TSB. I will look in my garage today and get you the exact part number of the PCV you will need to do the TSB

 

This quote is from another topic about oil consumption/smoke at startup.  My truck doesnt experience this but i did change the pcv valve a few wks ago

Part number is 12572717

[bobc]

Hey Ryan,

 

Thanks for the quick response!     I'll check this out and get back to the list with the result.  I recall reading something that has me thinking the PVC is located near the airflow sensor.  Right?  

 

I'll probably still drop it off at the dealer where I bought the truck becuase it was sold with a 2mo, 2k warranty.   That'll provide a CYA just in case it's a deeper seated problem.  I have not noticed any oil consumption to date, then again I've only had it for 6 weeks/ 900 miles on the truck so far.  The *only* thing different about today that I can think of is that it's getting colder in the morning and I let the truck warm up for about 5 mins while waiting to be able to defrost the windshield, (which revealed to me that the defroster seems to only blow out of 2 of 3 vents...)

 

You can bet I'm going to be watchin the tailpipes (cat back flowmaster duals) closely for a while now.

 

This would be very very SWEET if this turns out to be the problem.  So far I've been really happy with the truck.  

 

Thanks again for the assist!  

 

bobc

 

(no sig yet...)

[RyanbabZ71]

the pcv valve is located (standing in the front of the truck) on the drivers side (right hand side) next to the block.

 

I have a picture from Tom and can email you when i get home later tonight

[bobc]

Thanks Ryan.  Much appreciated.

 

I'll have to create another post about noisy quarter windows... seeing as I have that problem too.  doh!

 

later!

bob

[bobc]

Ryan,

 

No need to send the pic.  I ran across the PVC valve pic you mentioned.  Then I went out and looked at the PVC and it's definately the 'old' style, not the newer fixed orifice type.   I'll change it if the dealer doesn't...

 

While I was under the hood I also checked the oil level and it appears to be high which is not good, imho.  But these long snaky dipsticks are not the easiest to read so I'm not sure how much too full it is.     Probably should drain the oil and replace with proper qty for good measure.

 

We shall see what the dealer has to say.  Maybe I'll buy an extended warranty on the way home tonight.  

 

later

bob

[99silveradoz71]

Welcome aboard.  I used to have blue smoke at start-up on my 92 Jimmy  It was caused by oil leaking at the valve seals.

[bobc]

Thanks 99,

 

I too have had the smoke at startup on my older vehicles.  In fact I've personally r/r'd heads on 3 seperate vehicles over the years for worn guides or tired seals.   I guess bottom line, I don't believe a 2001 truck with 44k miles on it should have worn guides yet.  Of course what do I know.  I was driving a '77 ford 4x4 for 16yrs...  Kinda new to all this high newfangled hands off disposable technology.  I'm used to looking at the problem and seeing the cuase, not looking at what the computer says.  

 

The strange point about this situation IMHO is that it only happened this once since I've owned the truck.  The cloud was huge, but stopped, and not a puff since.  I'm watchin the pipes closely now.   Usually valve seals don't fix themselves, although if a seal popped off and then reseated itself... well, it wouldn't be fixed.. but I'm sure it will pop off again!  (and no I haven't been over reving the motor. :-D )  I'm inclined to think there is some possible for the motor to accumulate oil in the intake, a cylinder, or via some type of plumbing like the PVC.  However the PVC line is lower than the intake and higher than the oil 'waterline'.   Older BMW motorcycles are notorious for smoking on start up when you park em on their side stands becuase the oil level would be high enough to drain into the lowest cylinder.   This is closer to the behavior I'm seeing.  

 

Anyway...  

 

At this point I plan to buy an extended warranty and wait it out.  Hard failures are easy to deal with, intermittents suck rocks.  Logging this at a dealership at this point could do more harm than good (unless it's an easy fix of course) becuase I don't want an extended warranty company denying my claim becuase it's a documented "pre-existing" condition.   Of course this all assumes that I'm going to have someone else do the work on this truck.  Time will tell.  If I figure this out I will definately pass along the pertinant details.

 

 

See ya,

bob

[BlueRado]

bobc,

 

Agree w/ Ryan on the PCV being the most likely, and I think you're right to assume an LS1 derived engine w/ 44K miles shouldn't have worn valve stem seals.  Not that it can't happen, I guess.

 

Did the cloud appear to be oil definitely combusted in the engine as opposed to dropping onto hot parts and burning?  Either way, if you suspect that the engine is overfilled, and can't verify for sure, I'd change it, and the filter, run it for a few miles, let the oil settle out for 1/2 hr, then check on level ground to see where it falls on the dipstick, so this mark now becomes your new full mark. (Hope this doesn't sound remedial!! )  I've known engines to push out excess oil (overfilled), but not usually, to my knowledge, through the cylinders.

 

Good luck, and keep us posted!  

[RyanbabZ71]

what color smoke was it?  At around 20K once when i started my truck it wanted to die and a PUFF of white/greyish smoke came out of the tailpipe then the truck died.  Started right up after that and has run fine since

[bobc]

Hey Guys,

 

Thanks for additional interest in the problem.  I'm definately going to drain the oil and refill this weekend just to be safe.   The oil is showing well above the holes and cross hatching of the dipstick.  Better safe than sorry.  Overfilling seems most likely to blow out the main seal... and I don't want that either!  No worries BlueRado regarding "remedial" comment.  I'm a new guy and for all you know I may not know the difference between a Ford and a Chevy.  

 

 

I actually have quite a bit of mechanic background but mostly with motorcycles.   Have been wrenching on my own cars, trucks and motorcycles since 1980 or so.  BUT I will admit being new to Chevy's and working on any of the new gen auto's/trucks.  Was quite amazed to see the intake manifold was plastic on this truck!   =:-o

 

Ryan, the smoke was very slightly blue white.  Smelled of oil and definately came from within.  Truck had been sitting for 5 hrs and was stone cold.  Smoke was immediate and slowly died out, which is why I suspect pooling somewhere, cylinder, intake or ? over worn guides.  Ran fine, didn't stall or anything.  Only clue to a prob was visual.  Smoke volume tapered off within maybe 1-2 mins.

 

Not even one puff since.  Must be Fixed!  ;-)

 

later!

bobc

[bobc]

Latest update.

 

After about 8 clean starts over 1.5 days, the plume was back late yesterday.  

 

Picked up the TSB specified PCV, which is actually marked "fitting" vs PCV.  I'll give that a shot over the next few days and see what difference I encounter.  A friend of mine suggested documenting the problem with a video cam, seeing as it's so intermittent.  If anything that may come in handy if I get the run around at the dealer...  

 

I'm also noticing a pretty chunky/rough idle.  So I'm thinkin I'll pull a couple plugs too see if they are getting oil fouled.

 

I hate buying used...  It's not like people sell vehicles becuase they love them.

 

later!

bobc

[BlueRado]

Thanks for keeping us updated bobc.  Sounds like a challenge!!  

 

Here's a good thread regarding the PCV on this site, in case you missed it:

 

Click Here

 

I'd definitely be sure you got the new "fixed orifice" PCV and adjust the oil level then see how it fares, but also check your PCV hose to see it's not clogged.

 

Fraid I'm about out of ideas @ this point!  ???

[bobc]

Thanks BlueRado,  I found that thread while trying to get more info about the PCV when Ryan brought it up the other day.

 

Oil change is planned for the weekend, (assuming the dealer doesn't have it).  One other point re: oil.  I've definately noticed that cold startups are considerably louder in the past week.  The morning temp is now in the mid to high 40's this week for me so I think that is contributing to the clatter.  According to Helm manual 1.5 minutes of clatter is to be considered normal.  Nice.  The joys of EPA mandated Fuel Efficient oils, read that as THIN oils.  Some cars now are being spec'd for 0W30!  NO thanks.  I'll probably switch to 10W30 or 10W40 at the next change.

 

I *hope* the new clatter is not related to the oil.. then again if warranty (3 weeks left) wants to drop a new 6.0L in there I won't bitch.  

 

later!

bobc