Hello,
2015 Z51 C7

My alternator died last week and I brought it to the dealer to have it repaired. Dealer quoted $811.03 for the alternator repair, $289 for a new battery (which is lame since my battery is under 3 years old), and $359.99 for fuel induction services "due to carbon build up". Is the fuel induction service something that is required? Car has 80k miles, but don't see anything in the manual on intervals to have the services rendered. I put the highest grade fuel I can find at the pumps in Oregon, 92. Have some trouble trusting the dealers, so wanted to get a second opinion.

 

Not sure if you really need the fuel induction service, but $811 is criminal for an alternator change. I believe a new alternator is $400 so they are charging you $400 for labor to put a new one in. Crazy.

 

Damn lol. I wish I knew a bit more about the mechanical side of cars. I've had some fun cars but just never had the brain to understand what I'm looking at or doing, admittedly, so I always end up paying a shop for work.

 

Next thing they will charge you for,,,,, Shop Boy Charge, $200 driving the car into the bay, oh,,,,, you want it out of the bay? cha ching $200 more.

 

I feel you. I am blessed enough to understand how to take these motors apart and rebuild them, so I never have to go anywhere for service. I have already had my lt4 apart various times to upgrade different parts. If you wanted to do the alternator yourself, it is extremely easy and I'll bet there is a video of it somewhere. All you really have to do is disconnect the battery, Remove the intake (to get access to the tensioner), use the tensioner to remove tension and remove the belt, disconnect the two connections to the alternator, and remove the bolts (2 if I remember correctly) that hold the alternator in place.

 

Define "dealership". There are a lot of people there and I know of 1 guy doing the actual job. That is the guy you need to know if you can trust or not. If you are talking to the service advisor, IMO, they are little more than a hotel clerk booking you a room for the night. I know I can't trust the SA for anything since he lied to me. That said, he is there to book the tech I want to use. I usually discuss the job briefly with the tech and then tell the booking clerk I want John Wick to do a the alternator job. That goes well usually. When I let the SA tell me things, it usually has a problem.

GM Parts Direct has the alternator for my 16 Stingray going for $310 so it can only go up in price when you get it from the parts counter. Just for the hell of it, make a call to the parts counter and ask how much an alternator costs for your car. What is the labor rate at that dealer? What is the number of hours for the job? That tells us if the price is good or not.

Not always but I have seen a few alternators that get overworked by a bad battery and killed because the idiot owner didn't change it when he/she should have. I have also seen a good battery killed by a bad alternator. Before we sling accusations around, test the battery. 3 years means nothing. Back in 91, I bought a new F-body. A few months later, the battery died. Replaced it under warranty and a few months later, it died again. After that, it lasted quite a few years. Go figure. Each time the alternator tested good. Is it a fair precaution seeing as how the battery can cause a lot of issues when it is going out and you just had a bad alternator? Can't say I wouldn't myself.

I use Top Tier gas. Why? Because it was the most convenient. Where I work, there is a Costco that sells the cheapest gas around. How do I know? Because I saw a camera crew do a report on them from afar when the Mom & Pop gas stations were screaming about how Costco was running them out of business or hurting their profits. Well Duh! I paid for a membership and I expect some perks. That said, when I took my injectors out of My C4 after 100K, they were not flowing as good as when they were new. I took them to a tech college that had a flow bench and tested the numbers. I sent them to FIC for cleaning and testing. They gave me a report of what it was and what it runs after cleaning. I also retested the injectors I got back. All numbers were about right so I know FIC did the job. There was some varnish build up. One of the injectors tested bad for flow which FIC found out to be a collapsed basket filter. After that was replaced, it too ran at spec. Can it have varnish build up on the injectors? I believe so. That said, if all they do is hook up a can of BG44 to the fuel rail and run it for a bit, I think I will pass and wait till I take the injectors off and have them cleaned along with other parts of the intake when the day comes.

 

At 80K, I would at least replace the belt and some have said the tensioner is a weak spot? If so maybe that too? Thoughts?

 

I would guess they are doing the belt. Not sure if they are doing the tensioner since we didn't have a breakdown of the $811.03 but what is the labor rate and how many book hours is the alternator?

 

Yeah, it could never hurt to replace the tensioner at those miles as I have heard of a few failing, but probably not totally necessary. The belt as well while your there wouldn't be a bad idea. In my opinion, at those miles many serviceable items, water pump, alternator, belts, etc. tend to start showing signs of the need for replacement, os I wouldn't be opposed to replacing any of those, but I wouldn't jump down a rabbit hole replacing anything and everything unless there was evidence of actually needing it. Just my 2 cents.

 

Any fuel treatments won't address carbon build up because these cars are not port injected. They are direct injected, so the fuel doesn't come into contact with the intake valves.

Fuel treatments however can be good for keeping the injectors spraying well. You just need an $8 bottle of PEA based treatment if concerned, drop that into the tank yearly.

 

I don't know about seeing any testing for this. I have actually seen my injectors tested at 100k. Also the improvement that the flow bench shows. Never seen PEA testing other than the theory and testimony from the SOTP customer.

 

It's elective and an alternative to the dealership service thats a few thousand percent profit margin.

 

Has either proven to be as effective as actually cleaning the injectors?

 

I already answered that there is no need to do carbon cleaning through the fuel system as this engine is direct port injected. The fuel does not come into contact with the intake valves.

If the OP wishes to engage in fuel cleaning he can just buy PEA and DIY it. Whether he needs it or not cannot be determined by us over the interwebs.

 

But it can be determined by a laboratory test. That the sellers are unable and/or unwilling to show the results and methodology for critique make me call BS on their claims of efficacy.

 

There are publications out there that document carbon deposits and the impact PEA has on reducing them. You don't have to believe them.
https://www.sae.org/publications/tec...ontent/962012/
https://www.sae.org/publications/tec...ontent/952449/
https://www.jstor.org/stable/27034660

 

Wish I could read those articles but I don't have a subscription. Seems like the video states that base gas, something we will not encounter, seems to be better? I'm also curious if the articles mention testing if the build up reaches an equilibrium with pump gas. Is that equilibrium a problem or already factored in? Seems like my interpretation of what the video is saying is that if you have a serious issue, maybe a cleaning might help. But if you have no issue, you can still clean but it will build back up and reach a certain point and stop. So, is that build up at the equilibrium point harmful?

Back to the OP's question, is it worth anything to clean it? Sure, it is nice today but it will come back. If it doesn't do any harm, why clean it every 10K?

 

Sola dosis facit venenum

 

AND,,, it seems the PEA will make a new, clean, engine dirtier.

 

But if it goes to a point and stops there, what is the harm, assuming they factored it in? Is it necessary to be 100% clean except for "Show and Tell"?