I came across a Acadia 3.6L chain stretch (http://www.gminsidenews.com/forums/f53/acadia-3-6l-chain-stretch-98372/) thread on GM Inside News Forum. The 3.6L V6 engine in question is the SIDI 3.6L (LLT) engine but it's based on the NA 3.6L (LY7) found on the current generation Malibu and shares much of the same components including the timing chains (there're three, count 'em) and sprockets. It looks like they over-engineered the planned obsolescence by a mile. I think it's imperative that those of you with the 3.6L engine keep up with oil changes and check the oil level regularily.

30K so far and I don't use any oil between 6K changes. Using Mobil 1 though.

It has been a common thing with the 3.6L V6 for a while. There have been traverses, G6's, a lot of CTS's, and a couple malibu's that have come through the shop I work at. On the good side, once it is repaired GM says that it most likely will not need to be done again. Either there will be noise from the timing chains or it will seem fine and it will set codes. A couple guys at the shop can fix them quickly now.

I came across a Acadia 3.6L chain stretch (http://www.gminsidenews.com/forums/f53/acadia-3-6l-chain-stretch-98372/) thread on GM Inside News Forum. The 3.6L V6 engine in question is the SIDI 3.6L (LLT) engine but it's based on the NA 3.6L (LY7) found on the current generation Malibu and shares much of the same components including the timing chains (there're three, count 'em) and sprockets. It looks like they over-engineered the planned obsolescence by a mile. I think it's imperative that those of you with the 3.6L engine keep up with oil changes and check the oil level regularily.



Thanks for the info, I will start checking my oil level to be on the safe side! I am curious on how many miles were on the Arcadia? Was this a fairly new/low mileage Arcadia? Sounds like it really doesn’t matter since GM had possibly over engineered or made a error on this design issue! Again I will keep an eye on my oil level and hope for the best. Every bit of info helps us all!

Thanks :)

Sigh, it looks like they just had to fiddle around with it, something about smaller pitch and more links for noise reduction (as if the noise was that big a deal).:rolleyes: I remember other manufacturers using plastic timing chain guides (again for noise reduction, major dumb idea) with less than stellar reliability record. Well, at least the repair is covered by GM 5/100 powertrain warranty.

All the ones that I have seen fail, fail within the warranty period (earliest was 20K on a traverse). I am not sure why they had to change it though. They really don't seem that much quieter in comparison to older designs.

Thanks for the confirmation. Here's hoping those on this forum, at least wth proper maintenance, don't get bit by the problem.

Wow, that's disturbing! Sounds from most of the posts like it's a DI issue (like the Caddy has), but some of them suggest it also affects the 3.6 in any car, including the 'Bu. With all the issues we've seen on this forum I'd say we've done quite well if we've dodged that bullet, because this is the first I've heard of it, here or anywhere else.

Chrysler was great at having the nylon timing chains break down (get stretchy and skip a tooth) usually in the 80-100,000 mile mark. I got lucky and had one get over 225,000 when I traded the car off.

Some have failed at 4K, so it's a design problem, not oil.

Some have failed at 4K, so it's a design problem, not oil.

Care to elaborate how you came to this conclusion? Isolated incidents of early component failure aren't indicative of a "design problem" per se. Plus, if you neglect your oil, especially during the first 4K, you can expect problems.

@ starship,
How can you neglect oil in first 4K?

I came across a Acadia 3.6L chain stretch (http://www.gminsidenews.com/forums/f53/acadia-3-6l-chain-stretch-98372/) thread on GM Inside News Forum. The 3.6L V6 engine in question is the SIDI 3.6L (LLT) engine but it's based on the NA 3.6L (LY7) found on the current generation Malibu and shares much of the same components including the timing chains (there're three, count 'em) and sprockets. It looks like they over-engineered the planned obsolescence by a mile. I think it's imperative that those of you with the 3.6L engine keep up with oil changes and check the oil level regularily.

OK now in terms we can understand -- what is the actual failure ?

How can you neglect oil in first 4K?

I'm not sure whether this is a facetious remark but WTH (since I've already responded to the other one-liner remark). Not keeping a close eye on the oil level during the break-in and, worse, not paying attention to the Oil Pressure light would be what I call neglecting. I was once asked what the teapot sign was and why it was "flickering on my brand new car."

OK now in terms we can understand -- what is the actual failure ?

The 3.6L engine has three timing chains, with the primary chain around the crankshaft sprocket and two camshaft intermediate drive shaft sprockets. Each intermediate drive shaft then has a sprocket that drives a secondary chain for the intake and exhaust camshafts on that bank of three cylinders. One or more of these timing chains can stretch from premature wear. Like chevyguy8893 (http://www.chevymalibuforum.com/forums/member.php?u=5274) stated, "there will be noise from the timing chains or it will seem fine and it will set codes." The noise is from the loose chain(s) and the codes, to the effect of the crankshaft and camshaft position correlation problem. Of course, the latter will turn on the malfunction indicator.

It is funny because this always comes down to the GM oil life monitoring system. The problems that have happened are the cause of people going till the OLM is at 0% and then doing an oil change. The GM V8's in the tahoe's, silverdao's, impala ss, etc. end up burning oil because of sludge build up since the OLM doesn't seem to trip on the oil change warning till around 10K between oil changes for some. So, either the engines PCV systems is suldged up or the rings are stuck in the pistons and the engine has to be re-ringed.

In the case of the V6 the timing chain tensioner is pressurized by oil pressure, so, if oil sludge gets to the point where it plugs a passage way it would cause issues with a improperly tensioned timing chain. Also, it may be related to an alignment problem from the factory installation of the chains. So, keeping up with oil changes may save you this issue, but there is a chance it may be something else to cause it to fail.

I would like to get an answer to a question or two, then:

I have the V6 with about 2300 miles on it and around 60% on the OLM. I have been planning to go to about 10% and then changing it to full synthetic, then going to closer to 0% or a maximum of 1 year before changing it again.

If I keep dino oil in it would it be better to change it based on miles, and if so, approximately when?

With full syn in it I was planning to change at ~10,000 miles or 1 year max. Would you recommend a different interval?

I'm not sure whether this is a facetious remark but WTH (since I've already responded to the other one-liner remark). Not keeping a close eye on the oil level during the break-in and, worse, not paying attention to the Oil Pressure light would be what I call neglecting. I was once asked what the teapot sign was and why it was "flickering on my brand new car."



The 3.6L engine has three timing chains, with the primary chain around the crankshaft sprocket and two camshaft intermediate drive shaft sprockets. Each intermediate drive shaft then has a sprocket that drives a secondary chain for the intake and exhaust camshafts on that bank of three cylinders. One or more of these timing chains can stretch from premature wear. Like chevyguy8893 (http://www.chevymalibuforum.com/forums/member.php?u=5274) stated, "there will be noise from the timing chains or it will seem fine and it will set codes." The noise is from the loose chain(s) and the codes, to the effect of the crankshaft and camshaft position correlation problem. Of course, the latter will turn on the malfunction indicator.

Ah now thats clear -- Thank You

Buy the way guys I checked my oil this am and Im jsut at the hash marks.

I had my oil changed Nov 6th 2010. I was right next to my mechnaic when he finished th oild change. When he did the last mesurement I was in the middle hole of the hash marks. Since the last oil change i only put on 565 miles.

Lastly is anyone noticing a loud Whine like a straining transmission ???

Thanks bedbug !

You're quite welcome.:) The oil level on the dipstick can vary depending on how level the ground is and how long the car has been sitting. I check my oil biweekly or so, at the end of a work day before heading out. That way I don't have to wipe the dipstick and don't have to worry about how much oil is trapped under the valve covers.

The common source of whine is the power steering pump (will get louder when the steering wheel is turned) and transmission (will change with the engine RPM). I don't have the former (have EPS) and haven't noticed anything with the latter.

I'm not sure whether this is a facetious remark but WTH (since I've already responded to the other one-liner remark). Not keeping a close eye on the oil level during the break-in and, worse, not paying attention to the Oil Pressure light would be what I call neglecting. I was once asked what the teapot sign was and why it was "flickering on my brand new car."



Oh I see... I would call this "neglecting the engine". That is the reason it's got me puzzled.

It is funny because this always comes down to the GM oil life monitoring system. The problems that have happened are the cause of people going till the OLM is at 0% and then doing an oil change. The GM V8's in the tahoe's, silverdao's, impala ss, etc. end up burning oil because of sludge build up since the OLM doesn't seem to trip on the oil change warning till around 10K between oil changes for some. So, either the engines PCV systems is suldged up or the rings are stuck in the pistons and the engine has to be re-ringed.



10K interval should not a big deal today. Mazda tells 7.5K interval for dino oil.
@10K, if the engine has sludge issue, I would go after GM especially all changes were within OLM limits.
IMO, 3K intervals are gimmick. I go by 6K~7K intervals.

10K interval should not a big deal today. Mazda tells 7.5K interval for dino oil.
@10K, if the engine has sludge issue, I would go after GM especially all changes were within OLM limits.
IMO, 3K intervals are gimmick. I go by 6K~7K intervals.

No, it shouldn't be an issue to go 10K between oil changes. GM's fix for that is to go onto an oil consumption test which takes a while to do and then submit the info to them at the end. Then they decide if it has an issue. GM does take care of it most of the time though. I run generally around 6K on my oil changes and that puts my OLM at between 50-60% with my driving habits and about two oil changes a year depending. It is cheaper for me to maintain my car than have it fail earlier because of an OLM system.

I agree with an oil change, even if done too often, is cheaper and more convenient insurance than a repair. Gotta stay practical!

Not meaning to hijack the thread, but on a similar note, if I were to use low viscosity synthetic ATF for my A6 would that cause any issues? I read how member 05ls uses that in his '05 LS and figures it nets him a pretty good mileage increase. I'm interested in that, but also in treating the mechanism the best I can. That should lend itself well to extending the life of it since I intend to keep this one as long as I can.

Thanks for your answers already, and thanks in advance as well! :)

DEXRON VI specifications are tough to meet without a synthetic base oil component and thus your choices will be between the full synthetic variety and synthetic blend. I doubt there're any fuel economy gains to be realized here. Since some additives are sacrificial, changing it on time or earlier is what matters.

DEXRON VI specifications are tough to meet without a synthetic base oil component and thus your choices will be between the full synthetic variety and synthetic blend. I doubt there're any fuel economy gains to be realized here. Since some additives are sacrificial, changing it on time or earlier is what matters.

Thank you very much! Then that's what I'll do. When it's time for the tranny to be serviced I'll have it filled with full synthetic.

I have the V6 with about 2300 miles on it and around 60% on the OLM. I have been planning to go to about 10% and then changing it to full synthetic, then going to closer to 0% or a maximum of 1 year before changing it again.

If I keep dino oil in it would it be better to change it based on miles, and if so, approximately when?

With full syn in it I was planning to change at ~10,000 miles or 1 year max. Would you recommend a different interval?

You know, that OLM reading has been bothering me. It turns out, based on the read of Lambda forums, it looks like the OLM on the LLT (and most likely Ly7 and others) has been recalibrated for 2011. Whereas it would go as far as 10K before, the target OCI appears to be around 5K now (about in line with "2300 miles on it and around 60%"). I wonder any 2008-2010 3.6L owners who had their ECM flashed recently are now seeing the oil life go down twice as fast as before. Anyway, the bottom line is, 3.6L owners probably should not go over 5K between oil changes to be on the safe side. I know for fact that this is about in line with what Toyota has been recommending on the 3.5L (2GR-FE), 6 month or 5K. Since friction modifiers are sacrificial (used up in a linear relationship to the number of revolutions), I'd think doubling the OCI on synthetic oils is stretching it too far.

I don't religiously obey the OLM on this car.

My OLM showed 36% Oil life at 5,500 miles since the last change.

I only use Mobil 1, fully synthetic, and change the oil and the AC Delco filter every 5,000 miles. When I do, the oil comes out pretty black. I would NEVER go past 5,000 miles... I might even start changing it every 4,000 miles. Its very easy to do on the 3.6L. And it only costs me about $25 bucks since I do it myself.

Although I have noticed that if I put 5.5 Quarts of oil in the engine (which is what the owners manual says is the capacity) it shows up as half a quart too much on the dipstick. Now I only pour 5 Quarts, and it is at the top hole of the dipstick, and that is good enough.

You know, that OLM reading has been bothering me. It turns out, based on the read of Lambda forums, it looks like the OLM on the LLT (and most likely Ly7 and others) has been recalibrated for 2011. Whereas it would go as far as 10K before, the target OCI appears to be around 5K now (about in line with "2300 miles on it and around 60%"). I wonder any 2008-2010 3.6L owners who had their ECM flashed recently are now seeing the oil life go down twice as fast as before. Anyway, the bottom line is, 3.6L owners probably should not go over 5K between oil changes to be on the safe side. I know for fact that this is about in line with what Toyota has been recommending on the 3.5L (2GR-FE), 6 month or 5K. Since friction modifiers are sacrificial (used up in a linear relationship to the number of revolutions), I'd think doubling the OCI on synthetic oils is stretching it too far.

I don't religiously obey the OLM on this car.

My OLM showed 36% Oil life at 5,500 miles since the last change.

I only use Mobil 1, fully synthetic, and change the oil and the AC Delco filter every 5,000 miles. When I do, the oil comes out pretty black. I would NEVER go past 5,000 miles... I might even start changing it every 4,000 miles. Its very easy to do on the 3.6L. And it only costs me about $25 bucks since I do it myself.

Although I have noticed that if I put 5.5 Quarts of oil in the engine (which is what the owners manual says is the capacity) it shows up as half a quart too much on the dipstick. Now I only pour 5 Quarts, and it is at the top hole of the dipstick, and that is good enough.

Great input from both of you guys! The linear consumption of the additive pack and the color of the oil after 5K is evidence I can use.

SS, now that you mention it, it seems to be dropping much more quickly than my '09 V6 did, so that's a good thing for '11 as far as engine longevity goes.

Blink, I don't have the facility to be able to change the oil myself. But twice a year (I drive ~10K/year) is still affordable and cheap insurance.

http://www.blackstone-labs.com/free-test-kits.php

Here are the folks I use for oil analysis. They are quick and I like seing how the oil is performing and the engine is wearing. BTW, I have 30K on my Bu and the oil is darker but clear when I change at ~6K. I am using strickly Mobil 1 with a Delco filter.