My 2023 base C8 has 7,200 miles on it; and I took it to the dealer for the 5,000 service two months ago. The car runs fine and is a joy to drive. However. I now have a warning message telling me to "Change Transmission Filter immediately". How can this be after only 7000 miles?

I dont understand. I have an appointment next week but wonder...is this rare, and is it covered under warranty.

Sounds serious to me.

 

The service to change your transmission filter is at 7,500 miles not 5,000. You can change the filter before that BUT GM recommends changing the filter again at 7,500 miles in order to be in compliance for your warranty.

Did you use your "Free" service for the oil change and transmission filter when you had 5,000 miles? If you did, you will have to pay for the transmission filter change at 7,500 miles and I believe that charge is around $600.00. (There are a few threads on this within these forums. Do a search and you will see what others paid).

Here is a link form a recent post from last week regarding changing the transmission filter too early and than again at the 7,500 mile mark.

https://www.corvetteforum.com/forums...at-7500-a.html

 

I heard GM extended the 1st service out to 2 years, or 7500 miles. This way the DCT filter and 1st oil change gets done for free. Don't go beyond 7500, because then it'll be on your dime.

 

Please describe what the "5,000 service" is since it does not appear on the maintenance schedule. I assume that you had your first service done prematurely at 5,000 miles where they change the engine oil and filter and the transmission filter and switch the tires side-to-side.. Since the transmission is producing contaminants during break-in up to 7,5000 miles, GM expects the transmission filter to be changed at 7,500 miles - even if was changed earlier.

 

Your dealer didn't reset the DCT filter change interval at your 5K mile service? That is if they changed the DCT filter at 5K miles.

 

GM extended the expiration date of the first free service from 1 year to 2 years, and there is no stated mileage for expiration. But - that in no way changed the maintenance requirements of the C8. Engine oil must be changed at 7500 miles, or 1 year, or when the oil life monitor says so. The DTC external canister filter must be change at (or near) 7500 miles.

 

Your post answers a question that I have been asking for a while now! For the 2023 C8, which have the DCT filter life monitor, at what mileage does the message to change the filter appear? This would help to answer the question of how close to 7500 miles is close enough. Did you get the message at exactly 7200 miles? Did it really say change the transmission filter immediately? And what was the percentage of DCT filter life when the message first appeared?

 

And, based on the fact that he got this message at 7200 or thereabouts, and it said change it immediately, we now know that 7200 is close enough to count.

 

I’m just surprised it gives such a dire warning "Change Transmission Filter immediately" that clearly can scare the sh-t out of owners and no need for it! The warning light should simply be “DCT Filter Change Due”.

 

The idea that if you changed your DCT filter at 7000 miles that you need to change it again in 500 miles and can't go at least another 7500 miles (if not more) before changing it again just defies logic.

 

I know, I asked him to confirm exactly what it said - but have not see a response yet. The Owners Manual says the message will be:
'REPLACE TRANSMISSION FILTER SOON". I'd like to know exactly what it said, the miles when it appeared, and the percent filter life when it appeared.

 

First, and I said this before, GM screwed up that engine oil/filter change from my two C7s that ONLY said change when the OLM says change! The OLM in the C7 & C8 takes care of miles, engine revolutions, oil temp being insufficient for a long enough time to evaporate much of the water that gets past cold pistons etc. etc.

They confounded the 7500 DCT filter requirement with the much clearer Engine Oil/filter requirement, when the OLM says!

I also agree with RKCRLR that changing the DCT filter at 5000 miles (for whatever reason he changed at 5000) then again at 7500 is irrational BUT meets the GM requirement. Guess he could have "paid for" the engine oil/filter at 5000 miles IF it was OLM driven and at least got the free DCT filter (and flush) at 7500 miles.

I know some have said they must be combined to be free but I sure would have tried to get both covered separately if below 2 years. BUT if the dealer doesn't get reimbursed can't blame him for not doing!

As I said in prior posts need some what ifs from GM!

 

My mistake. The exact words are "Change Transmission Filter Soon". The car has precisely 7500 miles on it today and I believe the message started around 7200.

I deal with a small dealership in a rural town and they did in fact change the oil around 5500 miles for free, but at that time I did not inquired about the filter .

This could go one of two ways. When I take it in the service advisor will see that the car is less than one year old and I am entitled to a free filter.


Orrr they could say we changed the filter for free at 5500 and now you need a new one for ($600. ?)

As you can see, im a rookie when it comes to Corvettes. I just dont want to spend $600 unnecessarily

Bill

 

What service is listed on your bill? It should list if the transmission filter was changed or not.

 

Either only changed the engine oil & filter or changed the engine oil & filter and also changed the DCT filter. GM only has a single reimberement code for the first service so the dealer got reimbersed for the full service (whether or not they changed the DCT filter) if they didn't charge you for the first service. It will be betwen you and the dealer now if the dealer decides to help you out. Also, an important part of the DCT filter change is to perform a hydraulic system flush prior to changing the DCT filter which many dealers overlook.

 

Sorry I do not have the bill. I guess I am just worrying about something that may or may not happen. If the answer is that they changed the DCT filter at 5500 I am not going to change it again at 7500.

 

Just remember that the change of transmission filter at 7,500 miles is required by GM to keep your warranty in good standing. That could be an issue down the road if you didn't follow their service schedule and especially when the transmission is not fully broken in until the 7,500 mile mark as per GM.
Either way, good luck with the dealer and hopefully they will take care of you.

 

If you don't change it again, and something happens to the transmission, you are SOL. GM requires it to be changed at ~7500 miles, even if you had it changed earlier. This is because the transmission/clutch packs are still breaking in up to the 7500 miles mark (or so GM says). So between 5000 miles and 7500 miles there is potentially still some excess debris being produced and being trapped by the DCT filter. It might have been different had you had it changed at 7000 miles.

You admitted you are a rookie at this. The transmission itself is a $20k item. Don't make a $600 mistake that could cost you thousands down the road. If you don't care about your warranty (5 years for drive train I believe), then by all means, ignore the service requirements. Either way, even if they didn't change the DCT filter at 5000 miles it will most likely be on you unless you argue with the dealer as there is only one free service provided by GM - and you already had one.

 

Here's the thing. GM reps, on at least two occasions have stated that if you have the filter changed "early", that wear in debris will continue to accumulate up to 7500 miles and you must have the filter changed again at 7500 miles. It begs the question though - how early is too early? In one case they used the specific example - if you change at 3000 miles you must change it again at 7500. The caution about changing early is now in writing in a Tech-Link article, at this link

https://gm-techlink.com/?p=17254

which says "If a customer elects to have the filter changed before 7,500 miles (12,000 km), it should be changed again at 7,500 miles (12,000 km)."

The article also never says how early must it be to require changing again at 7500 miles.

But, thanks to you , we now have an additional data point - the message to change the filter soon appeared at 7200 miles. The manual says change it as soon as possible after that message appears. So we know 7200 miles is not too soon. But is 5000 too soon? I'm just not sure. I would probably change it again at 7500 (mine was changed at 2500 and I do plan to change it again at 7500). It is not just a warranty issue - there really is wear in debris accumulation between 5000 and 7500 miles according to GM. But if you are comfortable ignoring those statements and rolling past 7500, at least consider that you probably do not want to go a full 22500 more miles before you change it again. Assuming the only issue is DCT filter loading, my guess, using totally made up assumptions, is that if you changed it at 5000 miles on the odometer, you might be able to go an additional 17500 miles from the filter change at 5000 miles (reading 22500 miles on the odometer). That's based on what I think is a worst case assumption about how wear in debris is shed during the 7500 mile transmission break in period. But its not what GM says, and its not what I would do. Its just one extra filter change in the life of the car, why not do it in conservative way.

 

You're making assumptions here and stating your own conclusion as facts which just isn't true.