Hello, people. My 2012 is running well with about 30K miles on it. There is a cable TV show, Auto Experts, and they do sound knowledgeable, and it has come up several times that the GM-recommended Dexos oil is inadequate for this engine, and was decided by bean-counters, not engineers.

This varies from the usual advice of following what the owner's manual says.

They say the timing chain is particularly at risk for early failure, and I have also heard of it stretching, causing loss of power.

So, I switched to synthetic, following the Auto Experts advice, with a European specification of A3B4. In my imagination the engine sounds a bit smoother. There has always been some noise under acceleration, a little like Rice Krispies, which I thought perhaps was pre-ignition, but a GM mechanic assured me it's all normal. Trying high-test gas made no difference.

Whether that noise has anything to do with the timing chain I have no idea.

I also see some hints that the timing chain was beefed up after 2010, but despite some time searching am not getting very far learning more about that.

Is there any information about the timing chain in the 5th-gen V-6 engine, and of a higher-quality synthetic oil helping?

Thanks to all.

Charles

P.S. I did a track-day recently (fabulous!), and the corner garage did a few pre-track maintenance items, but also changed the oil (without asking), which however was new at lay-up last Autumn. They used Dexos. The oil now smells burnt to me, on the dipstick. Other observers disagree. But is that possible after a day of very hard driving? I'm just going to have it changed back to synthetic.
2012 Camaro 2LT RS

 

All Dexos oil is full synthetic.

When I worked at the parts store, I worked with a guy who was a part timer but worked full time at a garage. You would not believe how many stories he had of people having issues for not using Dexos oil. GM didn't spend hundreds of thousands in R&D for the oil if it wasn't adequate to do the job.

 

Thanks, MKC,

This has prompted me to try searching again. I find that dexos 1 (gas engines) is now in its 2nd generation, which unlike the 1st generation, is all fully synthetic.

Center For QA, dexos 2015

I didn't know that dexos is not a brand, but a standard. The generation 2 specification was issued in 2015. One of the many brands is GM's own ACDelco.

Whether the 2nd generation specification allays the concerns of the Auto Experts people, I do not know. How valid were their concerns in the first place, I of course cannot adjudicate.

GM dexos
Oil Can Henry's on dexos
Edmunds on Manufacturer's Oil
Hendson: dexos1 Motor Oil...Required

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My other question remains: can hard-driven (dexos) oil develop a burnt smell? If so, should the engine get an early oil change?

Thanks again.

Charles

 

Any oil could develop a burnt smell if subjected to long periods of load and heat. There is also the possibility that it is just the new oil picking up any former sludge that had formed in the engine. You could also be burning a little oil. If it concerns you, send a sample into one of the many oil labs. They'll test your oil and let you know what kind of condition it's in.

I don't remember any Dexos oil ever not being synthetic. I state that just because an oil is not Dexos certified, doesn't mean it's not a good oil. Some companies (like Amsoil) meet/exceed the specs but don't want to pay the premium to be Dexos approved.

 

Thanks again, MKC,

I will think about oil testing.

Here is a page about "Gen 1" dexos brands, many saying "blend".

Charles