2011 Tahoe White/Blue Smoke on Startup, Dealer Says New Engine

[comfreak]

Noticed within the past few weeks when we would start the truck cold in the garage, we'd get a puff of white smoke, minor blue hue, but very white. It billows for about 10-15 seconds, then goes away. The truck runs perfectly fine. No temperature issues or overheating. I performed a combustion leak test, found no exhaust in the coolant which appears to be at the normal level.

It's a 2011 model year with the Z71 package and 146,000 miles.

Noticed that it was low on oil, very low. Was due for an oil change and took it to the dealer we normally use and are comfortable with.

They diagnosed as follows and said the engine needs replacement:

"TECH BEGAN DIAGNOSIS WITH COMPRESSION TEST & VERIFIED NO EXTERIOR MOTOR LEAKS CAUSING LOW OIL PRESSURE. UPON FURTHER INSPECTION TECH VERIFIED THE OIL RINGS / PISTON RINGS IN MOTOR WERE FAILED CAUSING INTERNAL OIL LEAKS . TECH RECOMMENDED TO REPLACE MOTOR. CUSTOMER DECLINED REPAIRS AT THIS TIME."

Quoted me $6,400 for a new engine out the door including some coolant hoses.

Question 1: How long can I drive this truck if I just keep checking the oil level and making sure it's good? It runs like a beast and we love it.

Question 2: Would some additive possibly help the issue? I see some Rislone products that are supposed to help seal the piston rings.

Question 3: Is it worth a second opinion? Does this diagnosis seem reasonable?

Not sure where to go with this. The vehicle runs fine, it's in great condition, we don't want to get rid of it, drove it 9 years. Any ideas or experience in this, TIA!

 

[Jason in DLH]

Second opinions are always good and would find a dedicated engine shop in the area to see what they would charge to overhaul the engine.

 

[ls1frc]

Could easily be something as simple as worn valve seals.

If it were me, I'd do a DOD delete and keep driving it. I bet it's fine.

If you are looking into additives, the Liquimoly line of products actually work. I am using their MOS2 additive to quiet my cammed engine down and it actually does work.

You could try their engine flush then do an oil change, then add the Moly additive

https://products.liqui-moly.com/additives/oil-sludge-flush.html
https://products.liqui-moly.com/additives/truck-series-oil-treatment.html

 

[Doubeleive]

As long as you keep oil in it you can drive it till the wheels fall off, the problem can be fixed for less, gm dealers just don't want to, you can take it to a independent shop that you trust.

 

[wsteele]

Definitely get a second opinion. Ideally try and find a highly respected local shop (even better, one with ACDelco signs on the side of the building). Have them do a diagnostic just like the dealer did and see if they come to the same conclusion. A compression check and leak down will tell you a lot. 146K doesn't seem right for wearing out rings. My Yukon (5.3L LMG AFM/Flex) needed new pistons/rings at 95K miles, but that was due to some design flaws that should be fixed in your model year.

As far as driving it, if you can put up with the smoke at startup, keep it topped up with oil and keep an eye on misses that may start cropping up from fouled plugs (something you can deal with in any case if they do show up), running it like you are should be fine for a long time.

If it does end up needing a rebuild, the price they quoted you might not be out of line for a dealer swap for a genuine GM reman, if the shop rate is high enough. You can definitely do better than that from a reputable independent, even with a GM reman. If you go with one of the many other reman choices, you would probably bring it in more like $4500. A rebuild by a local builder should be less than that. If you pick the right independent shop and they find the same thing the dealer did, they will likely provide you with a whole range of options, all coming in less than the dealer.

Good luck.

 

[iamdub]

Noticed within the past few weeks when we would start the truck cold in the garage, we'd get a puff of white smoke, minor blue hue, but very white. It billows for about 10-15 seconds, then goes away. The truck runs perfectly fine. No temperature issues or overheating. I performed a combustion leak test, found no exhaust in the coolant which appears to be at the normal level.

It's a 2011 model year with the Z71 package and 146,000 miles.

Noticed that it was low on oil, very low. Was due for an oil change and took it to the dealer we normally use and are comfortable with.

They diagnosed as follows and said the engine needs replacement:

"TECH BEGAN DIAGNOSIS WITH COMPRESSION TEST & VERIFIED NO EXTERIOR MOTOR LEAKS CAUSING LOW OIL PRESSURE. UPON FURTHER INSPECTION TECH VERIFIED THE OIL RINGS / PISTON RINGS IN MOTOR WERE FAILED CAUSING INTERNAL OIL LEAKS . TECH RECOMMENDED TO REPLACE MOTOR. CUSTOMER DECLINED REPAIRS AT THIS TIME."

Quoted me $6,400 for a new engine out the door including some coolant hoses.

Question 1: How long can I drive this truck if I just keep checking the oil level and making sure it's good? It runs like a beast and we love it.

Question 2: Would some additive possibly help the issue? I see some Rislone products that are supposed to help seal the piston rings.

Question 3: Is it worth a second opinion? Does this diagnosis seem reasonable?

Not sure where to go with this. The vehicle runs fine, it's in great condition, we don't want to get rid of it, drove it 9 years. Any ideas or experience in this, TIA!

What doesn't add up, IMO:

Maybe it's just the way they wrote the notes, but it reads like they started out with a compression test to check for EXTERNAL oil leaks. You don't run a compression test for this. Furthermore, unless you had a busted head or block (which would shower oil everywhere) an external oil leak wouldn't cause low oil pressure. You didn't mention you had low oil pressure- do you? Did they record the results of the compression test? No mention of spark plug condition? Maybe they're just not good at being concise. But, to me, it sounds like they're being awfully vague and unclear for condemning an engine with "only" 146K miles.

Badly worn rings would burn oil all the time, especially during acceleration. White puffing at a cold start could mostly be condensation which is common this time of year and may be worse due to the recent weather- where are you located? The light blue puffing is oil, and if that's only at a cold start, then it's likely worn valve guide seals. You could be experiencing beginning symptoms of AFM-related failures. Any ticking at startup? Yours, being a 2011, should have the latest updated equipment. But it could be an early 2011.

I'd pop off the driver's side valve cover to see if it's the updated design and to gauge the presence of varnish/gunk buildup inside the engine. I'd check the records to see if it has the AFM pressure relief valve deflector installed, either after purchase or from the factory. I'd perform the procedure as outlined here: https://static.nhtsa.gov/odi/tsbs/2014/SB-10065822-9133.pdf, maybe twice. You can use a much cheaper chemical than the GM stuff: Motor Medic. @donjetman might have more to add to this. After all of that, I'd add a catch can and let 'er rip, keeping a close eye on the oil level.

Instead of bothering to investigate the presence of that valve deflector and to eliminate (or at least stave off) a failure point, you could have AFM disabled in the tune for about $65ish.



Questions here for organization:

1) Do you have low oil pressure?

2) Where are you located and did you recently move there from a vastly different climate?

3) What oil do you use and how often do you change it?

4) Any odd noises, particularly at startup?

 

[Bill 1960]

I wouldn’t do a thing quickly, just monitor the oil consumption rate and start shopping for a second opinion. Smoke on startup could be rings or valve seals, however a low compression test result is indicative of rings not valve seals. Did they give you the compression numbers? Post them up. If they didn’t give you the data, you didn’t get the diagnostic facts you paid for.

Also, a low compression result is typically followed up with a wet compression test where oil is injected into the cylinder to help the rings seal. Was that done?

The dealer knows most owners are not spending that kind of repair money and I’m sure they’d like to motivate you to trade it in on a new one.

 

[comfreak]

UPDATE SINCE ORIGINAL POST: Dealer performed oil change on Sunday (1/14) before they started diagnosing the problem so at least it's now full. Brought it home yesterday, sat overnight in cold garage, started this morning, and ZERO smoke. Nothing, nada, zilch.

Could it simply be low oil level causing the smoke? I'll feel dumb but better.

Questions here for organization:

1) Do you have low oil pressure?

2) Where are you located and did you recently move there from a vastly different climate?

3) What oil do you use and how often do you change it?

4) Any odd noises, particularly at startup?

1) I did have low oil pressure before I realized that the oil was practically empty. Up until this point, have never had low oil pressure and never checked oil level between changes because never had an inkling that there was an issue. Let this oil change go a little longer than normal.

Timeline:

Noticed the smoke about 2 weeks ago. Did combustion test, nothing in the coolant. 3 days ago (1/13) checked oil stick, saw it very, very low (almost nothing) but didn't realize how low. Went to dealer 2 days ago (1/14) and received low oil pressure warning upon leaving driveway. Turned around, added the half a quart I had in the garage, the low oil pressure message went away, drove to dealer without issue (20 miles).

2) In Virginia. Having cool weather but nothing out of ordinary. No recent moves, been here a decade. Parked in garage every night which is usually above freezing.

3) It's DEXOS 1 5w 30, whatever dealer puts in. Changed usually around 4000-5000 miles. This time let it go a little longer due to laziness/schedule.

4) No odd noises, starts and runs like a champ. After driving for so many years, you can tell when something is "off" but nothing seemed out of ordinary.

 

[3JFamily]

Do the valve cover check. I have a 2006 but it also had a thick puff of smoke on start up. 152K miles.
I added half a can of Seafoam to the crankcase and it seems to have done a good job of clearing the smoke problem so far.
It has only done once again since adding the Seafoam.
I am due for an oil change and I'll add the other half of the can when I do the change.

 

[comfreak]

Do the valve cover check. I have a 2006 but it also had a thick puff of smoke on start up. 152K miles.
I added half a can of Seafoam to the crankcase and it seems to have done a good job of clearing the smoke problem so far.
It has only done once again since adding the Seafoam.
I am due for an oil change and I'll add the other half of the can when I do the change.

Is there some specific way to check the existing one? I have ordered the replacement driver side valve cover and intend to replace the existing one myself and then monitor the oil levels.