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'08 SRX V6
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Discussion Starter · #1 ·
I called the Dallas dealer today to set up a service appointment for the '08 V6.
The advisor told me my '08 had a new RECALL related to the timing chain stretching.
I got pretty excited, but unfortunately, he said it was just a computer re-program that was supposed to put less stress on the chain over the long run.
All I can think of is maybe something to do with the cam advance/retard programmig, or maybe lower full-throttle shift points.

When I take it in next week, I'll see if I can find out more.

At least it seems they have discovered it's a problem.

DG
 

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91 Allante (gone), 06 SRX (gone)
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.. he said it was just a computer re-program that was supposed to put less stress on the chain over the long run. ... At least it seems they have discovered it's a problem.
How much stress does a timing chain get subjected to? This sounds like the old GM - like folks that took their V8 Northstar SRXs in for a software change that detuned the engine.
 

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2007 SRX4 N*, 2004 Infinity G35 Coupe
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c5.......... "detune" is a four letter word in these parts, and this is a family friendly forum. :D Hope that is not what Wrench finds out.

PJ
 

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2005 Cadillac CTS 3.6L VVT
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the re-programming thing is the OLM interval only. For example if the OLM calls normally for an oil change between 8k miles and 10k miles, now with the update(re-programming), it will call for an oil change between 5k miles and 8k miles. I don't have the exact number but its an example.
 

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2011 SRX Luxury, formerly in 2007 SRX V6 CPO
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15 Posts
My 07 SRX went in for service today. Rep mentioned the open recall to reprogram computer to protect timing chain. He didn't sense that it was anything that was going to make a big difference. But I'm driving a brand new DTS over the weekend while a part comes in for an airbag sensor. Will try to report by seat of my pants if in fact the solution involved any de-tuning.
 

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91 Allante (gone), 06 SRX (gone)
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From a post on another forum by a GM service tech (non-Cadillac, I believe) about the FWD variant of the 3.6:

"I heard it through the grapevine GM is putting a stop to the chain replacement in lieu of a recall that reprograms the ECM to ignore the stretch. Great, now we get to put all the chains on and heads with valves."
 

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'08 SRX V6
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542 Posts
Discussion Starter · #9 ·
So.....the consensus so far is that it's just a reduced mileage on the oil change warning, or a loosening of the stretch criteria before the fault code sets? Fabulous!

I take her in tomorrow, so I'll quiz them pretty hard about what they are doing to MY car. It always upsets me when a dealer does something to my car under the guise of warranty entitlement. We all know who paid for my factory warranty, and it sure ain't GM. (Soapbox time, now I feel better).

DG
 

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2007 SRX4 N*, 2004 Infinity G35 Coupe
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I feel your pain. Changing the oil change interval (to sooner) will do nothing to mitigate any timing chain issue (stretching) and detuning to take stress off the timing chain takes away power you bought and paid for. I would also be interested in what the dealer service tech has to say about one, the other, or both.

PJ
 

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srx
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I have a 2009 SRX v-6 and at 34,000 miles I got the ECU codes and dealer replaced timing chains. Just got the recall letter this weekend. I called "Customer Assistance Line" yeah right - waited for a tech person for 6 minutes and got cut off, called again and waited 18 minutes - still no one. (also gave a call back number). This problem has been out there for years - lets fix it right!
GM vehicles I've owned:
1. 1979 Chevette - best
2. 85 S10 blazer - leaked oil like a sieve - dealer told me best think I could do e "was buy another one" - I did - Ford
3. 2002 Trailblazer - shifted into low range on its own at highway speeds - Ford again
4. 2009 SRX - Not what I expected for a Cadillac - Lincoln this time.
Should have let GM close.
Al
 

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'08 SRX V6
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Discussion Starter · #12 ·
I got my letter today also.
But, the '08 is still in the shop, they had a lot to do: cam shims, diff seal, door hinges, tranny solenoids, cruise, brake calipers, sunroof; all the usual stuff.
So, I haven't yet gotten the whole story on the software change, other than the reduced oil-change interval.

When I dropped it off last week, the service rep said the chain problem was due to people never checking the oil between the 15k service intervals, and just running almost totally out of oil before the "Change Oil" light came on. Many of the V6's do use a quart every 2-3k or so, and that's enough to get totally empty before the "change" light comes on.

So..... it's really us careless owners who never raise the hood on our cars, and let them run out of oil.
I suppose the N* engines don't have as many problems because they have an oil level sensor - as do all the other luxury CUV's in the class.

Have all you guys who have had the chain fail been guilty of letting the oil get critically low? I doubt it.

I'll see if I can get further info on the software changes when I pick it up.

DG
 

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...................So..... it's really us careless owners who never raise the hood on our cars, and let them run out of oil.
I suppose the N* engines don't have as many problems because they have an oil level sensor - as do all the other luxury CUV's in the class.

Have all you guys who have had the chain fail been guilty of letting the oil get critically low? I doubt it.

I'll see if I can get further info on the software changes when I pick it up.

DG
Wrench........the SRXs with the Northstar V8 don't have an oil level sensor that I am aware of......just an oil pressure light.

PJ
 

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07 SRX V6 AWD Sport Package
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I got my letter from Cadillac today. It says .."we have determined that under certain driving conditions, and with extended oil change intervals, the timing chain could wear prematurely and cause the illumination of the Service Engine Soon light. Timing chains wear can be affected by the age of the engine oil and driving conditions.

What We Will Do: To ensure that your vehicle will not experience this condition, your Cadillac dealer will change the calibration of the engine control module, including the engine oil life monitor, which in most cases will recommend more frequent oil changes. This service will be performed for you at no charge until February 28,2013.

So, I have just over 50K miles on the odometer, but fortunately, I have made a habit of changing the oil at 50% on the OLM with Mobil 1. My wife's '05 SAAB would probably go 15K miles between oil changes if I followed that OLM, but that has a turbo so it gets fresh Mobil 1 every 4K miles. I always thought frequent oil changes were cheap insurance, and now I have proof that maybe I was right and that doesn't happen too often. :)

The words in the letter that concern me, and several others here also expressed it, is the phrase "...change the calibration of the engine control module...". Is there a way to find out what they are doing to the ECM aside from reprogramming the oil life monitor? The 3.6 engine's power is good but I would not want it detuned at all. My SRX is loaded with options that add weight (20" wheels, AWD, Ultra View), so I don't want to lose any power. Also, "certain driving conditions" is a very vague phrase and I am not "certain" if that applies to me or not.

I love driving the SRX and hope to put another 100K on it, but I am concerned about how this will last over the years. I have gone well past 150K miles on my last 3 cars and I thought a Cadillac should be able to equal or better the lesser cars I drove in the past. Time will tell!
 

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'07 - 3.6l SRX RWD, '16 - 2.5l Subaru Outback, '95 - 4.3l S10 pu
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A lot of development went into the algorithm used to develop the OLM sytem. It appears they are saying it's wrong!
Those of you who have had the timing chains replaced..... was there any noticeable driveability or performance issues prior to the error codes? or were the error codes the first you knew of the problem?
I've got 37k on the 07. Change oil/filter at 7000 and frequently check the oil level. Usage has been less than 1/2qt between oil changes using Mobil 1 5W-50.
BTW I got the "Customer Satisfaction Program" letter also!
 

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they're not changing the calibration of the OLM on other cars... so it must be something specific to these engines, not the OLM system (right?)
 

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Chris I haven't searched to see if more than just this engine family is involved. I suspect it's related to the VVT system used. Living in Arizona (warmer climate) and with my driving habits on both of my GM cars w/OLM it's consistent that I can drive approx. 130-140 miles and the OLM drops 1%..... meaning I could go 13-14000 miles between oil changes. But I don't.
The letter suggested extended oil change intervals and "certain driving conditions" could shorten the timing chain's life. The "certain driving conditions" and how the pcm reprogram will address them is of concern.
 

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Yeah, I wish there was more specifics to the recall, but I doubt we'll get more info any time soon... and we may be debating the root causes of the timing chain issue for years to come.

And since the OLM system was brought up I thought I would re-post this quote from the forum's old guru. It's a really good description of the OLM system and in my opinion should be required reading for every forum member.
"One thing I can touch on and clear up.....the GM oil life monitor operation and my statement that ZDP (or ZDDP as you tend to call it here...most of the API literature just sticks to ZDP so I tend to use that) depletion is the basis for oil deterioration.

My spelling is poor but ZDP stands for zinc dialkyldithiophosphate which , as it sounds, is an anti-wear compound comprised of zinc and phosphorus.

ZDP is dispersed in the oil so as to be at a potential wear site if a surface asperity happens to break thru the oil film thickness causing the dreaded metal-to-metal contact. A molecule of ZDP must be present at that moment to prevent microwelding at the contact site which will cause material transfer, scuffing, scoring, wear and catostrophic failure. The concentration of ZDP in the oil will determine if there is ZDP present to work it's magic. The greater the concentration...the more likely a molecule of ZDP will be there...and vice versa.

By nature, ZDP is sacrifical. As ZDP is "used up" at a wear site to prevent micorwelding the concentration of ZDP decreases.... So...if you measure the ZDP concentration in engine oil in a running engine it will decrease at linear rate based on engine revolutions. Any given engine has a certain number of high potential wear areas where metal-to-metal contact could occur due to reduced film thickness and/or surface asperities....areas such as rubbing element cam followers, distributor gears, rocker arm pivots, push rod tips, etc...... The more of these areas the more ZDP depletion. The more often these features come in contact the greater the ZDP depletion. That is why, generally speaking, ZDP concentration in the oil, for any given engine, will decrease at a fairly linear rate when plotted versus cummulative engine revolutions. The more times it turns the more contact the more chance for wear the greater the depletion. This is as much of a fact as I could quote ever and is really not speculation or anything. It is proven beyond a shadow of a doubt in many studies. That is why it is ONE of the basis for determining oil life remaining and why it is THE basic premis of the GM oil life algorithm. It is only ONE of the things that determines oil life...but it is the one thing that can be tied to engine operation in a linear fashion and estimated very accurately by accumulating engine revolutions via a counter.

The GM engine oil life monitor counts engine revolutions and accumulates the number for the basis of the oil life calculation. It then adds deterioration factors for operating temperature, start up temperature, soak times, ambient, coolant temperature, etc... There are a LOT of factors that "adjust" or affect the slope of the deterioration but the fundamental deterioration is traced back to the ZDP depletion that is inescapable with engine revolutions. The specific rate of ZDP depletion is readily measurable for any given engine so that is the fundamental item that is first calibrated for the oil life algorithm to tailor it specifically to that engine. <<<< does that paragraph get anyone else excited besides me? laugh.gif

You would obviously like to get the oil out of the engine before the ZDP concentration gets so low that it is ineffective at being at the right place at the right time and preventing engine wear so that becomes the long term limit on oil life for that application.

The other things that determine oil life such a acid build up, oxidation, petane insuluables such as silicon from dust/dirt, carbon or soot build up from the EGR in blowby, water contamination, fuel contamination, etc.... are all modeled by the multipliers or deterioration factors that "adjust" the immediate slope of the line defined by the engine revolution counter as those items can be modeled in other ways and accounted for in the immediate slope of the ZDP depletion line.

The algorithm was developed over the course of many years by several lubrication experts at GM Fuels and Lubes, spearheaded by Doctor Shirley Schwartz who holds the patents (with GM) for the algorithm and the oil life montitor. I had the luck of working directly with Dr. Schwartz when the idea of the oil life monitor first progressed from the theoretical/lab stage to real world testing/development/validation. There were fleets of cars operated under all conditions that deteriorate the oil life for any and every reason and , thru oil sampling and detailed analysis of the oil condition, the algorithm was developed, fine tuned and validated to be the most accurate way invented yet to recommend an oil change interval by. As just one example, I have seen cars driven side-by-side on trips, one towing a trailer and one not, for instance, to prove the effectiveness of the oil life monitor in deteriorating the oil at a faster rate just because of the higher load, higher average RPM, higher temps, etc...and it works flawlessly.

The oil life monitor is so effective because: it is customized for that specific vehicle/engine, it takes everything into account that deteriorates the oil, it is ALWAYS working so as to take into account THAT INDIVIDUALS driving schedule, and it tailors the oil change to that schedule and predicts, on an ongoing basis, the oil life remaining so that that specific individual can plan an oil change accordingly. No other system can do this that effectively.

One thing is that I know personally from years of testing and thousands of oil analysis that the oil life algorithm works. There is simply no argument to the contrary. If you don't believe me, fine, but, trust me, it works. It is accurate because it has been calibrated for each specific engine it is installed on and there is considerable testing and validation of the oil life monitor on that specific application. NOt something that oil companies or Amsoil do. They generalize....the oil life monitor is very specific for that application.

Oil condition sensors in some BMW and Mercedes products are useful, also. They have their limitations, though, as they can be blind to some contaminates and can, themselves, be contaminated by certain markers or constituents of certain engine oils. Oil condition sensors can only react to the specific oil at that moment and they add complexity, cost and another potential item to fail. One other beauty of the GM oil life monitor is that it is all software and does not add any mechanical complexity, mass, wiring or potential failure mechanism.

There is considerable safety factor in the GM oil life monitor. Typically, I would say, there is a 2:1 safety factor in the slope of the ZDP depletion curve....in other words, zero percent oil life per the ZDP depletion is not zero ZDP but twice the concentration of ZDP considered critical for THAT engine to operate under all conditions reliably with no wear. This is always a subject of discussion as to just how low do you want the ZDP to get before the oil is "worn out" if this is the deciding factor for oil life. We would tend to be on the conservative side. If the oil life is counting down on a slope that would recommend a 10K change interval then there is probably 20K oil life before the ZDP is catostrophically depleted....not that you would want to go there...but reason why many people are successful in running those change intervals.

Please...NOT ALL ENGINES ARE THE SAME. The example above is an excellent practical justification of why you would want to add EOS and change the 15W40 Delvac in the muscle car at 3000 miles max and yet can run the Northstar to 12500 easily on conventional oil. You must treat each engine and situation differently and what applies to one does not retroactively apply to others. This is where Amsoil falls short in my book by proposing long change intervals in most everything if you use their oil. It just doesn't work that way. You can run the Amsoil to 12500 with no concerns whatsoever in the late model Northstar because even the oil life monitor tells you that for conventional oil off the shelf. Would I do that to the 502 in my 66 Chevelle...NO WAY. Amsoil says I can though. Wrong.


There are entire SAE papers written on the GM oil life monitor and one could write a book on it so it is hard to touch on all aspects of it in a single post. Hopefully we hit the high spots. Realize that a GREAT deal of time, work and energy went into developing the oil life monitor and it has received acclaim from engineering organizations, petroleum organizations, environmental groups all across the board. It is not some widget invented in a week and tacked onto the car.

The oil life monitor is not under the control of a summer intern at GM Powertrain per an earlier post....LOL Not that a summer intern wasn't compiling calibrations or doing a project on it but is under control of the lube group with a variety of engineers directly responsible that have immediate responsibility for the different engine families and engine groups. The idea that a summer intern was responsible for or handling the oil life monitor is ludicrous.....LOL LOL LOL"
 

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Thanks Rippy for passing on this most informative post from the forum's old guru. I strongly agree with you that it should be required reading for the forum members. Finally, one "plain English" synopsis about everything you need to know about (synthetic) motor oil and the oil life moitoring system.

PJ
 
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