Oil for GM 3.6l famous for timing chains.

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Oct 24, 2018
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Is there an oil brand you would recommend for a Buick Enclave? It has the infamous 3.6l high feature engine that is known for timing chain issues, owing to poor crank ventilation causing issues with sludge, heat and poor flow. Is there a good oil out there that might help with this. I usually use Pennzoil Platinum or Mobil 1, but I have heard Pennzoil can be prone to sludge?
 
The Pennzoil sludge issue is an old wives tale. Any of the Dexos 1 Gen2 oils will do the job. These oils have a specification that reduces timing chain wear. What year is your Enclave? The more recent GM 3.6's have been redesigned with different crankcase ventilation systems and a different (shorter) timing chain design.
 
Here is a thread with the same question.

 
The Pennzoil sludge issue is an old wives tale. Any of the Dexos 1 Gen2 oils will do the job. These oils have a specification that reduces timing chain wear. What year is your Enclave? The more recent GM 3.6's have been redesigned with different crankcase ventilation systems and a different (shorter) timing chain design.
2010.
 
Here is a thread with the same question.

Jeez. Forgot all about this!! Lol
Well I tried, low mileage oil changes, but at 23k on the clock I am putting in a new timing chain. I am glad I see I was being proactive on this. Lol
 
Pennzoil can be prone to sludge
Here's what the inside of our 2006 Outback's engine looks like after 15 years and 96,000 miles of using nothing but Pennzoil conventional 5w-30 changed every 3-5k miles.
pxl_20200926_145927331-jpg.30200
 
That is the problematic 3.6. After they started having timing chain problems they revised the oil life monitor to shorten the oil change interval. If your engine is still in good shape I would recommend 5,000 mile oil change intervals using a good Dexos synthetic 5W-30. I personally like Castrol Magnatec or Edge. My 2017 GMC 3.6 has a quieter start up (no cam phaser startup rattle) with Magnatec.
 
Here's what the inside of our 2006 Outback's engine looks like after 15 years and 96,000 miles of using nothing but Pennzoil conventional 5w-30 changed every 3-5k miles.
pxl_20200926_145927331-jpg.30200
And people say that it's impossible to get 100k clean non sludge non varnish miles with conventional even if you change it at 3k or no later than 5k.
 
And people say that it's impossible to get 100k clean non sludge non varnish miles with conventional even if you change it at 3k or no later than 5k.
It depends on the engine design, also many "conventional" oils now have synthetic in them to help meet spec.
 
 
I doubt an oil choice will help much with factory defects. But something in 0W40/5W40 viscosity is what I would run in that engine. Maybe even 5w50, if climate allows. May not help, but is a small safety cushion that will help me sleep at night. It's not like the Dexos certs help to minimize issues somehow, and Chevrolet still can't fix it either, even though the engine has been on the market since May 2006...
 
I also have the 3.6 high feature and hope to avoid doing the chains again. The most important thing is keeping the sump full.

I have used Penn Platinum, Valvoline, Valv Maxlife, Magnatec, QSUD, and they all work about the same. The PCV system sucks about a quart of oil into the intake every 1k miles of freeway driving. Less than half that with city driving. I just check the oil every 1k and add as necessary. And change oil every 3k.

Edit: I once tried 10w30 (prior to changing the chains) and the startup noise was worse! 5w30 all the way. 0w30 may also work but I don't plan to try.
 
Used whatever Dexos M1 with the weight called for (can't remember if it was 5w20 or 5w30) & M1 filter in my ex's 2010 Traverse. No issues with the chains & it had 185k mi on it when hit & totalled. The rest of it was a giant pile though...power steering, AC, torque converter, stereo, body control module...was so happy when it was totalled 😊😂
 
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