Oil Choice for Lowest Wear On Engine Timing Chain?

[Shannow]

Originally Posted By: FetchFar
Originally Posted By: CentAmDL650
The sprocket teeth should meet the rollers on the chain cleanly and evenly. If there is striking or impact it is because the chain or teeth on the sprocket are shot.


Its kind of an angled impact. I mean, at some point there must be a meeting between the sprocket tooth and chain cross-pin. Yes the angle helps a lot.


If you understood how these things (and gears) are designed, impact is engineered out of it.

Make the sprockets too small, for compactness (e.g. my Nissan,where they try to do DI into the piston bowl and parallel valve stems), and you increase the chain tension and the contact pressures between cam and chain, then have to rely more on material properties and lubricants than you otherwise would.

 

[Shannow]

Originally Posted By: 95busa
Originally Posted By: FetchFar
Originally Posted By: 95busa
Mos2 is retarded
... based on what facts? At least two oil formulators use it, Mazda 0w-20 and Schaeffer 5w-30 synthetics, so they are retarded?

talking about the miracle in a bottle additive, not an add pack. But sure, they are windowlickers too.


Retarded in the engineering sense ?

Definition please.

 

[Ayrton]

This thread makes me leery of the 2.8 GM V6 Turbo in my 9-3.

 

[Shannow]

Tourettes ???

 

[FetchFar]

Originally Posted By: Ayrton
This thread makes me leery of the 2.8 GM V6 Turbo in my 9-3.

Yep, I know, GM put out a bulletin 2895 in Europe for that engine to put in new carbonitrided timing chains. Complaint - Customer complain about SVS on, DTC P0016(1B) and P0018(1B) set in ECU. Further investigation reveals chain elongation.
Cause - Lack of robustness in the chain material properties aggravated by ages engine oil.
Production - Improved wear resistant timing chains (material improved and carbo-nitriding) introduced as of engine number HN 055 387 (29th Sep 2010)

Anybody with that car needs great anti-wear oil properties, not just average.

 

[FetchFar]

Originally Posted By: Shannow
Originally Posted By: FetchFar
Originally Posted By: CentAmDL650
The sprocket teeth should meet the rollers on the chain cleanly and evenly. If there is striking or impact it is because the chain or teeth on the sprocket are shot.


Its kind of an angled impact. I mean, at some point there must be a meeting between the sprocket tooth and chain cross-pin. Yes the angle helps a lot.


If you understood how these things (and gears) are designed, impact is engineered out of it.

Make the sprockets too small, for compactness (e.g. my Nissan,where they try to do DI into the piston bowl and parallel valve stems), and you increase the chain tension and the contact pressures between cam and chain, then have to rely more on material properties and lubricants than you otherwise would.


An impact does occur. I'm a mechanical engineer, but you don't have to be one to know that at some point the sprocket teeth must hit the chain link pin. Its kind of like a glider (no landing gear, only skids) touching down on a runway, it impacts and slides at the same time, at an angle, causing a bunch of wear on the skids, and if there was oil on the runway, you would also benefit from having some solid sacrificial material like Moly to keep the skids from grinding away.

 

[il_signore97]

Originally Posted By: FetchFar
What would be the best choice for lowest wear on engine timing chains?

What can be done to lube those chains better? GM issued recalls on past Traverse/Acadia/Enclave/Outlook/Cadillac LLT v6's to cause the OLM to call for more frequent oil changes. I know my 2011 Camaro v6 already came from the factory with the more-frequent oil change OLM settings, as this car drives me crazy with how much it wants OLM oil changes.

So whats the best strategy?



I realize that you're really searching for the root cause of the problem, and I doubt that you'll find it without an inside source. However, I think it's more than safe to say that it was a design problem, period. They are hardening their chains properly now, and the decreased OCI's through the reprogramming of the OLM is maybe just an insurance policy for them, or maybe part of the solution. We will never really know.

Also, the chains were stretching to the best of my knowledge, and not failing due to breakage. Big difference.

However, you can also look at it this way... Previously, when GM was NOT hardening the timing chain, what really caused the issue? We know that this D.I. engine does create a lot of fuel dilution, indicated by depressed flashpoint and viscosity, and increased wear. How do we fix this? More frequent OCI's, no matter what oil you use (or start with a much thicker oil in the first place to combat the viscosity loss from the fuel dilution). The non-hardened chain could have been susceptible to stretch due to oil temperatures that were continuously a bit too high (maybe not for the other parts of the engine, but for that particular non-hardened chain).

But regardless, we all know that GM will not resort to a thicker oil, will not install oil coolers (or larger oil coolers) in their vehicles on their dime, and cannot adequately correct the fuel dilution issue that comes inherently with the D.I. engine design. So what is their solution? Redesign the chain / manufacturing process for the chain, and shorten OCI's to combat fuel dilution. Problem solved...

You can try whatever you like with your own vehicle, but it's hard to know which direction to move towards when you don't know the root cause of failure.

 

[OVERKILL]

Originally Posted By: FetchFar
Originally Posted By: Ayrton
This thread makes me leery of the 2.8 GM V6 Turbo in my 9-3.

Yep, I know, GM put out a bulletin 2895 in Europe for that engine to put in new carbonitrided timing chains. Complaint - Customer complain about SVS on, DTC P0016(1B) and P0018(1B) set in ECU. Further investigation reveals chain elongation.
Cause - Lack of robustness in the chain material properties aggravated by ages engine oil.
Production - Improved wear resistant timing chains (material improved and carbo-nitriding) introduced as of engine number HN 055 387 (29th Sep 2010)

Anybody with that car needs great anti-wear oil properties, not just average.



What additive is going to stop the elongation? There isn't one.

Sounds like the solution is the fitment of the updated chain.

 

[il_signore97]

Originally Posted By: OVERKILL
What additive is going to stop the elongation? There isn't one.

Sounds like the solution is the fitment of the updated chain.

Exactly. Stretch / elongation failure is very different from excessive wear causing breakage / failure.

 

[FetchFar]

il_sinore97, excellent summary. Its interesting all the things GM CAN'T/WON'T do to offer more help. Now they have stuck us with 4,000 mile (approximate) oil changes even though wear studies have shown this doesn't help, too frequent for me, and extra cost over what consumers were told when they bought their OLM cars (like 10,000 mile OCI). GM can't specify any other better oil but a dexos1 oil, they can't specify heavier than a 30 oil (EPA fuel economy laws), they won't test & certify an anti-wear moly additive (corporate law) or ZDDP additive (cat convertors).

Yet the consumer wants to do a little something to easily get more life out of them.

The fuel dilution thing must be looked at. I should send in a sample of oil to blackstone labs at 5,000 miles to see if thats really the case in an engine with tight rings at 35,000 miles.

 

[FetchFar]

Originally Posted By: OVERKILL
What additive is going to stop the elongation? There isn't one.

Sounds like the solution is the fitment of the updated chain.

Additives not going to help, even a little? Oh well, hard to prove either way without a properly done fleet taxi study over a year with extended OCIs, one group using Lubro Moly additive, one not. On a hunch, I'm going to bet that getting a little moly on those chain links might protect them better from wear.

Another thing I'm trying is to get out iron particles in the 0.1 to 30 micron range the oil filter misses, via using a strong magnet Dimple magnetic drain plug. If you try several small things, it ends up mattering, like in racing where a ton of small tricks add up to a win.

 

[nitehawk55]

The chain issue is more of a stretching problem .

Why worry on tiny micron iron particles ? they won't hurt anything small as they are .

 

[FetchFar]

Originally Posted By: nitehawk55
The chain issue is more of a stretching problem .

Why worry on tiny micron iron particles ? they won't hurt anything small as they are .


The stretching is from wear, not plastic deformation of the steel. Wear at each/every pin/link interface.

Engineering studies have shown they do matter at those sizes. Oil film thickness varies from about 0.1 microns to 20 microns depending on where in the engine you look. So small iron particles cause wear, tearing tiny canyons into the engine surfaces.

Now, except for using a microgreenfilter.com oil filter, or an amsoil bypass setup, I don't see any way to get hard silica (sand) out in the 0.1 to 30 micron range that slips past the air filter, oil filter, and rings.

 

[OVERKILL]

Originally Posted By: FetchFar

The stretching is from wear, not plastic deformation of the steel. Wear at each/every pin/link interface.


Curious as to what your source is for this?

 

[martinq]

Originally Posted By: FetchFar
The stretching is from wear, not plastic deformation of the steel. Wear at each/every pin/link interface.

I can confirm this having disassembled and inspected several types of worn chains. The is an initial 'stretch' after a chains is first installed and broken-in. Once the wear-points are seated the rate of wear is greatly reduced for the life of the chain.

This behaviour is similar to what we see in hydraulics, gear-cases and engines. There is a rapid accumulation of wear particles during break-in. If you can flush these out of the system then component life can be dramatically increased. Chains are no different.

 

[martinq]

I would think that any modern high-performance oil would address the wear issue. I would look for something with a good dose of Moly (or the newer trinuclear type) or something that performs as well in boundary lubrication.

Red Line, Mobil 1, Motul would be good places to start.

I believe that GF-6 is going to have a test to address chain-wear.

 

[martinq]

ILSAC to Add Timing Chain Wear Test to GF-6
http://www.pceo.com/node/262

"The one component that suffers the most from accelerated wear in GDI and GDI-T engines is the metal timing chain, which drives the camshaft(s) off of the crankshaft. Excessive wear can cause the check engine light to illuminate and could result in very expensive internal engine hardware repairs. Excess wear is evident in chain elongation which can disturb valve timing leading to degraded performance and higher engine out emissions. Researchers are not yet sure about the exact wear mechanism—it could be abrasive wear from carbon particles suspended in the lube oil or an interaction between carbon particles and the lubricant or both."

 

[OVERKILL]

Originally Posted By: martinq
ILSAC to Add Timing Chain Wear Test to GF-6
http://www.pceo.com/node/262

"The one component that suffers the most from accelerated wear in GDI and GDI-T engines is the metal timing chain, which drives the camshaft(s) off of the crankshaft. Excessive wear can cause the check engine light to illuminate and could result in very expensive internal engine hardware repairs. Excess wear is evident in chain elongation which can disturb valve timing leading to degraded performance and higher engine out emissions. Researchers are not yet sure about the exact wear mechanism—it could be abrasive wear from carbon particles suspended in the lube oil or an interaction between carbon particles and the lubricant or both."


Interesting, so this doesn't apply to port injection engines (or if it does, nowhere near on the same scale). Learn something new every day!

Yet another issue with Direct Injection.... It really does seem that we are all Beta testers for this technology, given the problems that continue to pop up.

 

[lonestar]

I have an 09 Enclave and thus have kept up with the TC situation as much as possible. I believe all of the 09 Lambda platform vehicles have been issued a supplemental 10 year / 100K mile (whichever occurs first) warranty on the TC. I know I got a letter from GM stating such. Clearly the materials used in the TCs in the pre 2010 3.6DIs were sub-par but other factors contribute to the stretching. The initial OLM programming, assuming conventional oil, was set to run out to 9K to 12K miles. The lead mechanic at one of the Buick dealerships in Dallas told me that people driving these vehicles never give their oil a second thought until the OLM light came one. Then, when convenient (no telling how many more miles they drove), they maybe would get the oil changed. The 3.6DIs use oil and the lead mechanic told me they saw many vehicles coming in down 2 or more quarts of oil when the OLM illuminated. When the oil level drops the TC in the 3.6DI does not get proper lubrication. Additionally, 9K to 12K OCIs was maybe overly optimistic for conventional oil, heck even synthetic oil, in this engine. UOAs on site supports this as well. Literally there were two types of TCs in the pre-2010 3.6DI – those that had failed and those that were going to fail.

So, the OLM was recalibrated (still assuming conventional oil) to try and accomplish two things, 1) hopefully try to keep the engines from getting low on oil due the majority of owners never checking their oil between changes, and 2) avoid oil from getting too contaminated as a result of fuel dilution.

For me my 09 Enclave car has 32K miles and will be 5 years old in Feb. 2014 and to my knowledge has none of the symptoms of the TC issue so far. However, my max OCI on this vehicle has been 4K miles, I am currently running PU, and I use the larger PF63 size oil filter instead of the OEM PF48 size. I check the oil once a week and keep the level at the full mark. In the past I have run M1 (horrible UOA in my engine), Amsoil, Kendall FS w/Titanium, and PU all 5W30.

For me, never again will I purchase a first year car or car with a first year for the engine or transmission.

 

[martinq]

Here's a nice article on chain wear:
http://www.diamondchain.com/understanding-wear-life.php

... and this chart illustrates the break-in and life-wear stages:
http://www.iwis.de/en/drive-systems/brands-products/elite/lubricants/initial-lubricants/