My dealership odyssey and claimed carbon buildup

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Vector

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I need some sound advice on a current dilemma I have with my dealership, and them wanting $$$ to fix something that should have been covered under my factory powertrain warrantee before it expired.

I had my 2015 in for service to determine why I was having a hard to slamming shift in late May 2020 and they replaced a control solenoid/valve and trans control module assembly, found a leaking shock, replaced various things under my powertrain and aftermarket warrantees. The engine was running very good back when I brought it to them in my view, but the check engine light was intermittently coming on.
I assumed the tranny might be helping to cause it to come on.
Anyway, they determined my bank 2 cylinder 6 lifter collapsed. So they replaced all the lifters on the right side. I remember asking them why they didn't do all 8 instead of just 4 on one side, and they said via camera I didn't need it.
They had it for 2 weeks until mid June, but I was happy they fixed it before my warrantee ran out.
I didn't pay anything for that job, as my powertrain warrantee covered the job.

So I get it back, and now it was running rough with the engine light still coming on. I brought it back to them, and they kept it another few weeks, and eventually said my high pressure fuel pump needed to be replaced because it was leaking into my crankcase. So they replaced it without charge to me under the warrantee.
They asked if they could drive it for 20 miles to make sure everything was ok, and I said yes, but when I picked it up, it was still running rough and the check engine light came on within a few hours.

I called them back and said I wanted to bring it back in, but they didn't have a loner for me. Furthermore, since COVID was occurring they said they were short on mechanics and would call me when I could come back in. I expressed my concern about my warrantee running out, but they said no to worry. Needless to say they never called me back, and when I called them every couple of weeks, I was put off.

In the mean time I took it to Autozone and their computer said the code was P219A Bank1 Air Fuel Ratio Imbalance. They said it was likely an Oxygen sensor that needed replacing, but who knows.

Anyway, I finally got them to agree to take it back in, and give me a loaner. Several weeks passed without them contacting me, and when they did, it was to tell me that I supposedly have heavy carbon buildup on the valves and they need to tear the heads off and polish all the valves to do the job correctly.

They said the job would cost about $3,500, and they were going to "do me a favor by putting it on the GM calculator and I would only have to pay $1,600 which was about 40% of the job".
When I asked them why it was not being covered under the powertrain warrantee, they said it had run out, otherwise it would have been covered. :banghead:
When I pointed out they should have discovered this problem back when I had brought it in the previous two times with my warrantee still valid, they said the buildup must have occurred in between. This was absurd, as only about 140 miles had been put on it, 20 of which they did during the "fuel pump break in".
When I balked at paying, then they tried to tell me that so few miles being put on it likely caused the buildup because of old fuel in my tank for having driven it so little.
Needless to say they can't have it both ways.

However the service manager gave me an ultimatum of putting it back together running rough and I could do whatever I wanted to, or fix it with me paying for close to half the bill.
I do not want to take it back with it running worse than when I originally brought it to them, but I also do not want to pay for something that should have been properly diagnosed and fixed when my warrantee was still in effect.

So what sage advice can you'll give to me as to how to proceed?
 

mb1500

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Take it back, don’t pay anything. Go somewhere else and get a 2nd opinion.

Usually in a situation like this the dealer will go to bat for you if you’re slightly over warranty. Looks like your dealer is trying to screw you over...
 
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Vector

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Take it back, don’t pay anything. Go somewhere else and get a 2nd opinion.

Usually in a situation like this the dealer will go to bat for you if you’re slightly over warranty. Looks like your dealer is trying to screw you over...

They still have it, will likely be doing the work, and expect me to pay 40%.
As to them screwing me over, they seem to view it as doing me a special favor based on the calculator since my miles are so low for a 2015.

I tried to do a search on carbon buildup for these motors, as the SA said they are known for it based on the variable 4 to 8 cylinder issue.
Anyone else have experience with this phenomenon?
 

mb1500

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Build up, by definition means over time. It is not possible for a normally functioning engine to accumulate any meaningful amount of carbon buildup in 140 miles. Period.

Carbon buildup is not a result of the AFM system, it is a characteristic of DI only engines. However this is blown out of proportion by many and is not a serious issue with these engines under normal operating conditions.

By reading your story in my opinion they did not fix your original issue and put it off until you were out of warranty. IMO you are still dealing with the original issue.

Your engine code could be a bad sensor OR it could be doing it’s job and alerting exactly what it says. AFR imbalance on the #1 cyl bank. Fuel, air, spark. Might have an injector issue. Running rough = misfire. Might have dropped another lifter. Mode 6 data would help identify if you have an obvious problem in a cylinder...
 
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Vector

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Build up, by definition means over time. It is not possible for a normally functioning engine to accumulate any meaningful amount of carbon buildup in 140 miles. Period.

Carbon buildup is not a result of the AFM system, it is a characteristic of DI only engines. However this is blown out of proportion by many and is not a serious issue with these engines under normal operating conditions.

By reading your story in my opinion they did not fix your original issue and put it off until you were out of warranty. IMO you are still dealing with the original issue.

Your engine code could be a bad sensor OR it could be doing it’s job and alerting exactly what it says. AFR imbalance on the #1 cyl bank. Fuel, air, spark. Might have an injector issue. Running rough = misfire. Might have dropped another lifter. Mode 6 data would help identify if you have an obvious problem in a cylinder...

That is what I was thinking also, but that is the lame verbal excuse my SA gave me. If the problem they are claiming is the reason for it running rough and causing the check engine light to come on, they missed in the first 3 times I brought it in to them. Also when they replaced the lifter on the one side, why didn't they notice the problem when they were in doing that work a few months ago?

I am not sure what I can do about it now, as they have my vehicle and have given me the choice of fixing it with me paying 40%, or they give it back to me running worse than when I first brought it into them?
 

mb1500

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I would push the dealer to make it right or take the vehicle elsewhere.

Contact GM directly with your issue and let them know that it is an ongoing issue that was not fixed properly.
 

sealandsky

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I need some sound advice on a current dilemma I have with my dealership, and them wanting $$$ to fix something that should have been covered under my factory powertrain warrantee before it expired.

I had my 2015 in for service to determine why I was having a hard to slamming shift in late May 2020 and they replaced a control solenoid/valve and trans control module assembly, found a leaking shock, replaced various things under my powertrain and aftermarket warrantees. The engine was running very good back when I brought it to them in my view, but the check engine light was intermittently coming on.
I assumed the tranny might be helping to cause it to come on.
Anyway, they determined my bank 2 cylinder 6 lifter collapsed. So they replaced all the lifters on the right side. I remember asking them why they didn't do all 8 instead of just 4 on one side, and they said via camera I didn't need it.
They had it for 2 weeks until mid June, but I was happy they fixed it before my warrantee ran out.
I didn't pay anything for that job, as my powertrain warrantee covered the job.

So I get it back, and now it was running rough with the engine light still coming on. I brought it back to them, and they kept it another few weeks, and eventually said my high pressure fuel pump needed to be replaced because it was leaking into my crankcase. So they replaced it without charge to me under the warrantee.
They asked if they could drive it for 20 miles to make sure everything was ok, and I said yes, but when I picked it up, it was still running rough and the check engine light came on within a few hours.

I called them back and said I wanted to bring it back in, but they didn't have a loner for me. Furthermore, since COVID was occurring they said they were short on mechanics and would call me when I could come back in. I expressed my concern about my warrantee running out, but they said no to worry. Needless to say they never called me back, and when I called them every couple of weeks, I was put off.

In the mean time I took it to Autozone and their computer said the code was P219A Bank1 Air Fuel Ratio Imbalance. They said it was likely an Oxygen sensor that needed replacing, but who knows.

Anyway, I finally got them to agree to take it back in, and give me a loaner. Several weeks passed without them contacting me, and when they did, it was to tell me that I supposedly have heavy carbon buildup on the valves and they need to tear the heads off and polish all the valves to do the job correctly.

They said the job would cost about $3,500, and they were going to "do me a favor by putting it on the GM calculator and I would only have to pay $1,600 which was about 40% of the job".
When I asked them why it was not being covered under the powertrain warrantee, they said it had run out, otherwise it would have been covered. :banghead:
When I pointed out they should have discovered this problem back when I had brought it in the previous two times with my warrantee still valid, they said the buildup must have occurred in between. This was absurd, as only about 140 miles had been put on it, 20 of which they did during the "fuel pump break in".
When I balked at paying, then they tried to tell me that so few miles being put on it likely caused the buildup because of old fuel in my tank for having driven it so little.
Needless to say they can't have it both ways.

However the service manager gave me an ultimatum of putting it back together running rough and I could do whatever I wanted to, or fix it with me paying for close to half the bill.
I do not want to take it back with it running worse than when I originally brought it to them, but I also do not want to pay for something that should have been properly diagnosed and fixed when my warrantee was still in effect.

So what sage advice can you'll give to me as to how to proceed?
That dealer is a joke - I'd take it somewhere else, anywhere else!
 
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Vector

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No guarantees the work will fix the issue, then what.

The SM said he would warrantee it for 1 year if I agreed to pay my portion, but I am not sure how legit that is. Plus if I move to some other area, the warrantee would presumably only be with this dealer.
 

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