2020 6.2L: misfires, lifter issues and engine replacement - SOLVED

[persistent]

my wife's 2020 tahoe started giving episodic check engine lights and had a rough idle a couple weeks ago. i do basic maintenance on this car and change the oil every 5k mi and oil filter every 20k mi. engine oil level looked fine, and when i used a scan tool (launch x431) it didn't show any notable engine-related trouble codes. as a result of having so little to go on for diagnostics, i had her take the car to a nearby dealership last friday.

the dealership takes 4 business days to make a substantive diagnostic response, where they eventually note some historical misfires, that they're checking spark plugs and fuel injectors, and a cylinder has low compression and is being tested for leaks. after 5 buiness days, they say "we removed the valve cover and found some sludge built up" and "there is a stuck lifter in engine. recommend replace engine". the quote to replace the engine is $14k.

based on what i know about the 2020 tahoe, i am to understand that stuck lifters that require replacement is not an uncommon scenario, but suggesting a wholesale engine replacement seems ridiculous. i did some searching here on the forum and found this recent thread where it sounds like a similar scenario has led to the (questionable) suggestion of an engine replacement from a dealership. as a result of what i read in that thread, i plan to get a 2nd opinion from an independent shop.

i appreciate any input here, thanks for reading.

 

[Fless]

What oil filters are you using that last 20k miles?

 

[Rygrego]

I've got to know why you wouldn't change the filter at every oil change. Such a minimal cost compared to 8 quarts of quality synthetic motor oil. The standard dealer response is engine replacement with a stuck lifter due to the probability of the camshaft being damaged also.

 

[15burban]

What oil filters are you using that last 20k miles?

Fram xg line says they're good for 20k and their fe line says 25k but why someone would go that long especially when changing the oil multiple times throughout that period.....

I use their fe line in my vehicles but it gets changed every 5k with the oil. Oil and filters are cheap compared to cam and lifters or a new motor.

 

[Marky Dissod]

... "there is a stuck lifter in engine. recommend replace engine." the quote to replace the engine is $14k.

There is something fundamentally wrong with an engine's INITIAL design specs,
such that when a SINGLE lifter gets stuck, the pound of cure is to replace the engine entirely.

In an ideal world, replacing that stuck lifter alone should be enough.
Do keep in mind, especially given the GenV 6.2L suicide issues lately,
that the fix you should be considering is to replace the two-mode lifters
with the lifters used in the 6.6L L8T (yes, this would require an ecm tune).

 

[B-train]

Holy crap! Oil filter every 20k????? REALLY??

Not trying to be mean, but come on man, you're down there anyways. This is probably the most worrysome post I've read in a long time. "I do my own maintenance every 5k, but NO filter."

You dealership diagnosis of SLUDGE is 110% correct. That filter isn't doing anything after 5000 miles normally. Then almost nothing at all after your oil change. Then almost nothing after the first 500 miles of your current schedule of filter change.

You need to be very careful at this point......change the oil AND filter with new. Then add some ATF or SEAFOAM and run for 500 miles. Change oil and filter. Do again for 1000 - 1500 miles. Change oil and filter. Do again for 3000 miles. Change oil and filter.......

Then stick with 5k, or less, with oil AND filter and you should be good. Your "cost savings for a 20k filter" just cost you WAY more. Don't belive all the filter advertised hype......it's a bunch of BS by marketing people who know Jack S H i T about engines.

Sorry to be so harsh, but this is reality if you want to be a DIY guy. 30 yrs experience speaking....

 

[Marky Dissod]

i do basic maintenance on this car
and change the oil every 5k mi
and oil filter every 20k mi ...

"we removed the valve cover and found some sludge built up"

I freely admit to not reading this slowly enough the first time.
If it makes you feel better, find THE ABSOLUTE CHEAPEST oil filter,
and change it every time you change the oil.

Engines cost more than oil. Engines cost more than oil filters.
Q.E.D.

 

[ivin74]

Holy crap! Oil filter every 20k????? W T F ??

Not trying to be mean, but come on man, you're down there anyways. Do you trip over $100 bills to pick up dimes too? This is probably the most absurd post I've read in a long time. "I do my own maintenance every 5k, but NO filter."

^X2
He should not be doing any oil changes period.

 

[ReaperHWK]

For sure the sludge was caused by the 20k mile oil filter changes. Wow! I bet if you cut one of those open after 20k miles it would be packed with crap and sludge. No good man.

Common sense says no matter what a filter says it will have the old oil and crap lodged in it just contaminating the engine.

 

[persistent]

What oil filters are you using that last 20k miles?

K&N.

i was just going off the packaging that said they were good for 20k mi. if the service interval should be every oil change, that's easy enough to adapt to in the future.

i'm really surprised at the amount of crap i'm catching for not changing the filter more often. my recollection of every car i've ever taken to a dealership is that they definitely would not change the filter every time the oil was changed. telling me i'm an idiot for not changing the filter more often does literally nothing to help me make a decision about the repair.

 

[Fless]

If it helps, the 2020 owner's manual states to change the filter when changing the oil (at least once a year).

 

[persistent]

ok, so everyone shows up to tell me i'm an idiot for not changing the filter often enough. i will be changing the oil filter with the oil from now on. my wife put a lot of miles on this car, so the oil filter has been changed at least once a year, albeit not at every oil change.

what about what i actually posted about - the 14k quote for replacing the engine? i'm legit shocked that the solution to the first clear sign of a problem is to replace the entire engine, rather than replacing some components, e.g. lifters.

 

[persistent]

after having a look on youtube, i found a video that i think is pretty informative in the context of my current problem.

if a lifter fails or gets stuck, it can damage the corresponding lobe on the camshaft, which requires replacing the camshaft. the video works out the cost of the replacement parts and the labor required, as quoted by a dealership, as roughly 2k in parts and 5k in labor (30 hrs). i also see that it is common for dealerships to advise full engine replacement, presumably to avoid customers being angry that a partial fix did not work and to maximize profit for their shop.

the video is only 1 year old, and the comments are rich with content from people who have had the same problem. i see several accounts of similar quotes to what i got to replace the engine, 12-14k.

 

[the 18th letter]

ok, so everyone shows up to tell me i'm an idiot for not changing the filter often enough. i will be changing the oil filter with the oil from now on. my wife put a lot of miles on this car, so the oil filter has been changed at least once a year, albeit not at every oil change.

what about what i actually posted about - the 14k quote for replacing the engine? i'm legit shocked that the solution to the first clear sign of a problem is to replace the entire engine, rather than replacing some components, e.g. lifters.

It’s a board of mostly enthusiasts so the posts about the oil filter got everyone going. Coulda been less harsh on you lol but at least the point was made and you get it now. Moving on, the lifter can sometimes be unstuck using Marvel mystery oil and Italian tune up trick. You can search it on the board and hopefully someone more versed will chime in. 14k seems high In the end.

 

[15burban]

If it's not within warranty I would recommend finding a known good smaller shop. If you can't do the work yourself for a job costing this much I would get multiple quotes if of course you don't know of a shop that does great work.

 

[ReaperHWK]

Well the issue like you said is dealer labor. It’s $220 an hour at my location. I had the dealer recently reprogram my stabilization control module and blind spot modules that I replaced and it took them 15 min each(30 min total). They charged me $450 since each job is 1 hour labor on their charge guide. Wow. So replacing some engine internals would get up there with an engine replacement unfortunately. Now if I was you I would:

1) take it to a small shop mechanic, they may be able to do the rebuild at a lower cost that makes sense

2) if you have an extra car she can use, I’d do the job myself in the garage. You can’t F it up any more lol. Pull heads, replace lifter and other parts on the top end. Then pull the cam (not sure on a Tahoe but I know most cars can do that with the engine in the car). Probably $1000 in parts if you buy them from online discount sellers.

 

[B-train]

Listen to @the 18th letter this is a good, cheap, option. Aka: the Tennessee Tune-up as well. LOL

1. Change the oil and filter
2. Add approximately 1/2 quuart of Sea Foam, MMO, or ATF (Ratio is on the cans of Seafoam and MMO).
3. Let engine idle with new mixture until it gets warm
4. Run in neutral at rpms of about 1200 to 1800 (think massaging the mixture into the system)
5. Take the truck out and do some moderate pulls through the gears (not WOT).
6. Listen to the motor - is it quieter or noisier?
7. If it seems like improvement is being made, then give it some more rpm and longer pulls. Then coast for a bit and let the decell cycle pull oil up and around under vacuum.
8. Make a long run to Costco on the freeway. Buy more oil and filters
9. Let truck cool and sit overnight. Fire up in the morning and see if noise is gone. If gone, change oil and filter. If still slightly present, repeat the process and change the oil hot afterwards.
10. STOP using 0w-20 and go with 5w-30 Dexos.

This may or may not fix it depending on how bad the lifter issue is, but I'd be willing to bet it will work.

As far as the engine price, that's a major amount of suck, but seems common in this market. An independent shop may be a better option. They can still put in new GM engines with the warranty as well. 3yr/100k miles - done many over the years as an independent

 

[Foxy]

I would recommend getting a new Camshaft and lifters. My wife's Tahoe had the same issues and I just replaced the Camshaft with a TSP afm/dod delete stage 1 Camshaft and lifters. You'll need a tune from HP Tuners and new hi-flow oil pump, plus the dod delete kit and your tahoe will be good as new with a little extra power. Price should only cost you $10,000-15,000 for parts and Labor depending on your location. A lot cheaper than replacing the whole engine.

 

[persistent]

Listen to @the 18th letter this is a good, cheap, option. Aka: the Tennessee Tune-up as well. LOL

1. Change the oil and filter
2. Add approximately 1/2 quuart of Sea Foam, MMO, or ATF (Ratio is on the cans of Seafoam and MMO).
3. Let engine idle with new mixture until it gets warm
4. Run in neutral at rpms of about 1200 to 1800 (think massaging the mixture into the system)
5. Take the truck out and do some moderate pulls through the gears (not WOT).
6. Listen to the motor - is it quieter or noisier?
7. If it seems like improvement is being made, then give it some more rpm and longer pulls. Then coast for a bit and let the decell cycle pull oil up and around under vacuum.
8. Make a long run to Costco on the freeway. Buy more oil and filters
9. Let truck cool and sit overnight. Fire up in the morning and see if noise is gone. If gone, change oil and filter. If still slightly present, repeat the process and change the oil hot afterwards.
10. STOP using 0w-20 and go with 5w-30 Dexos.

This may or may not fix it depending on how bad the lifter issue is, but I'd be willing to bet it will work.

As far as the engine price, that's a major amount of suck, but seems common in this market. An independent shop may be a better option. They can still put in new GM engines with the warranty as well. 3yr/100k miles - done many over the years as an independent

just spoke to the service rep and was told that the 6.2 L engine is on backorder from GM, with no estimated lead time. he told me it would take about a week to swap the engine out once they had the engine, but it could be 1 week or a couple months until the engine was available. given that it has taken 9 business days to get to this point, i'm inclined to pick up the vehicle and try out your suggestions. there is no telling how long i would have to wait for the engine swap to occur, considering the sluggish response time from the dealership. it feels like it is being slow walked as a game to get me to trade it in and buy a new car.

 

[Greaser007]

How about a Reman long-block from AutoZone ?