Eskimo1

Haha! Unless the coach discount is 100%, I'll have to pass. I'm already looking for an apartment now since I brought my '00 back home! :P

pepperpepper

​​​​​​​It was ESP per the service ticket, and our dealership is so small that there's only two technicians and the junior of the two is a Silver level tech. They don't let the lot guys touch the cars besides washing them, so I'm fairly confident that they didn't bork up my oil change.

F SANE IL

My 06 explorer did this and typically they all suffer this since those tentioners have springs in them that go had after a while. Basically spring is in there for startup and then the hydraulic takes over once engine fires up.

Explorers are known to have timing chain issues, which is why no one wants to replace those chains and they just motor swap.

HGR

Hello to you all, experiencing the same problem with the Porsche V6 TDI. I bought my Cayenne 2014 with approximately 65K on the odometer and had a "porsche approved certified pre-owned warranty" inclueded in the purchase.
I bought the vehicle back in March-April 2018. After having driven for approximately 2k miles, I started hearing the timing chain noise.
I am very familiar with this problem, due to the fact, that I am a managing partner in a Vehicle R&D firm with a strong footing in engine design, optimization and testing. Furthermore, I have A-1 through A-9 (A-9 being Diesel Engines) ASE certifications incl. the L1 "specialist certification" beyond my Master Tech credentials.
Mercedes Bluetec Diesels, in particular the ones of the ML 350 Bluetec 2010 and onward had the exact same issue with the timing chains.

At one point, I owned a GL 320 CDI and a ML 350 Bluetec--at the same time. The only thing different on these two engines are the piezo common-rail injection pressures (engine management system-ecu) and the exhaust aftertreatment system. What I mean by aftertreatment system is the DEF / SCR (selective catalytic reduction) which is only present on the bluetec and not on the cdi, in the case of the 08 GL and 11 ML of mine.

Here is the kicker, my ML started doing the noise at around 90 k miles vs. the cdi never started making any noise clear up to when I sold the vehicles at around 160-180 k miles.

Why does the ML Bluetec have such issues, as is the case with the Cayenne / Audi (not porsche diesel)? Well the answer is simmple, it has something to do with the active and passive regeneration of the DPF (diesel particulate filter) and the SCR filter. The SCR filter, which costs $ 3k for an ML 350 Bluetec also has a tendency to plug-up and cause back pressure, which in turn complicates things for vehicles with an SCR Filter. Why does it plug up, well the Urea or DEF injected in it, at low temperatures (diesel scandal) and slow driving speeds (low engine rpm and heat) does not evaporate and thus accumulates in the SCR.

The Nox sensors and quantity control injector (UREA / DEF) of the SCR system which injects urea into the exhaust system sit underneath of the car (open to water spray and the elements) of the ML 350 Bluetec (major issues with Nox sensors and the electronics). That problem is less of an issue with the porsche/audi diesel since that all happens pretty much by the firewall of the engine bay rather than underneath of the car. Regardless of the difference in location of the components, they still have the basic BOSCH aftertreatment strategy---meaning if the pressure differential sensor which mounts before and after the DPF in the exhaust stream measures a high enough deviation, the car will go into a exhaust/dpf regeneration.

What do I mean by regeneration? The engine changes fuel mapping, fuel injection timing, turbo boost, cooling parameters (in the spring or fall you will hear the cooling fan run, even though it isn't too warm yet for it to have triggered the fan to have come on , etc.) to increase the combustion and exhaust temperature from approximately 300 C to 800 C during normal highway driving.

That is not a problem right, because a gasoline engine already runs at approx. 800 C in the exhaust stream during heavy driving. Yes and NO. For a diesel to attain such high temperatures in the exhaust stream, upstream of the turbocharger, the combustion chamber temperature is literally exceeding WOT temperatures of a gasoline engine's max temp.

This active regeneration process, which I have described above, causes the engine block, pistons, valves, head, and especially the engine oil to heat up tremendously. The engine oil thins out, carbon deposits from wihin the oil separate out of the oil matrix and start to clump within the sump and engine block, which in turn starts blocking oil passages, etc. and potentially making check-valves, or oil control valves not fully operational--(people using CHEAP oil in these engines literally expedite engine failures 10 fold).

The thinning of the oil and the ACTIVE REGENERATION PROCESS that almost every modern EURO 5 diesel engine does a "couple" of times during its lifetime, is the cause of our "timing chaing problem". Which in reality, it is not the timing chain which is the problem, but the timing chain tensioners.

The cayenne diesel has multiple timing chains, depending upon model year, you can have as many as four timing chains in that engine. The oil pump is actually driven by a standalone chain--LOL. The timing chains are not at the front of the engine, but at the back of the engine, towards the firewall. Each timing chain has a tensioner and chain guides. The chain guides are made from metal and nylon. The timing chain slap, which is what we all hear during startup, is the timing chain banging on the tensioner and or guides. That will cause excessive wear on the tensioner and guides, potentially damaging a nylon guide, to the point that it will break off and end up in the sump.

For anybody starting their vehicle more than twice a day and hearing that noise during every startup, is 100% at risk of imminent engine failure!

Now you ask, why are we here in the US having more issues than anywhere else in the world, say Germany or Europe? The answer is simple and comes back full circle with Active and Passive Regeneration. In Europe in particular Germany, where the Autobahn has stretches of no speed limit, the vehicles are driven much harder, which in turn causes the exhaust temperature to naturally be higher than 300 C more towards 450C and the CFM (air throughput) Exhaust Volume is much higher being pushed through the exhaust, because the engine is revving higher than in the case with our 70-80 MPG Highway speeds. At these conditions, the exhaust, DPF, burns the soot out by itself, leaving the Pressure Differential Pressure Sensor from sensing substantial back pressure for a long time, which only if there is a high enough back pressure (differential in the dpf) does active regeneration occur. The Mercedes that I owned got documented by my staff, that the ECU did even more worse things to the engine, etc. which I am not going into further details here, but Mercedes Bluetec engines are the worst.

Even in the US, Sprinter Cargo Vans have hardly any mechanical engine problems (they do have Nox sensor issues, etc.)--why is that? Simply put, a Sprinter Cargo Van has a top speed of 80-85 MPH, therefore the gearing and rear end ratios are speced for towing and not comfort. That in turn implies that the engine is already revving beyond 3000 RPM going 65/70 MPH--hence these type of applications do not rely solely on active dpf regeneration, thus keeping the engine temps in the normal range, for a longer duration of time.

For the Mercedes the Star Diagnostic Program which is the MB TECHS Scanner can show how many miles the vehicle has driven since the last active regernation. The ECU in the ML Bluetec 2011 for instance thinks it is normal to actively regenerate every 300 miles--- which is total nonsense. If that is happening and you are using the dealer's oil or a lower grade oil, the engine is literally destroying itself.
The ECU light should come on, if the engine tries to regenerate sooner than say 1000 miles. In reality, dependent on driving, the car should not actively regenerate for several thousands of miles--that is the case in Europe. That is why, if you pull up an owners manual for a 2011 ML 350 Bluetec, it states that you should drive the vehile for around 100 miles at highway speeds every 600 miles (if memory serves me well)--total nonsense, MB was banking then on the fact that the exhaust would passively regenerate.

To conclude this post, at this time, I am having substantial issues, even for a person with my credentials and background to get my Dealer in OHIO, where I bought the car, to either remove the engine and replace all chains and tensioners along with the chain guides or just swap a new engine in---under my warranty.

I own over four Porsches a 964 Carrera 4 1990, a 1997 993 Bi-Turbo, 1967 911 S, and this not so great Porsche Cayenne. I do a lot of work in Germany, hence my connection with the Porsche Dealership at Stuttgart Flughafen. I have an ENGLISH email from my Service Rep. there, from his dealership e-mail address and his dealership letterhead, that states that this noise is not normal and the cayenne should not make such noise upon startup, but the Porsche Customer Service Hotline and Dealer Network in the US do not want to do anything.

I have accumulated over 20 K miles within the past 10 months; had the car serviced at the dealership every 3k miles; and have to say: I am very, very, very disappointed at the potential stupidity, ignorance or just lack of customer service at these dealerships in the greater OHIO area.

Whatever they are telling you, that this is normal--I have hard evidence beyond my know-how and experience owning porsches--that contradicts such input.

I already wrote a letter to Porsche USA, but never heard back from them. Right now, I am evaluating how much more time I want to invest in this, but since finding this thread, I thought to give this entire problem the justice it deserves.

Should somebody here want to start a class-action lawsuit, I would be more than happy to supply my knowledge and expertise.

I am new to this forum and have yet to get the hang of it, but I might upload videos and pictures at a later time.

HGR

I hate to break it to you, but the noise that you are all hearing is not “normal” or should not even be heard, during the first 150k miles of any vehicle, that has undergone reasonable care and was endowed with proper oil.

I am a managing partner of a R&D Firm that specializes in the automotive industry. My extensive “know-how” in this field (incl. my ASE Master Tech A1-A8 & A9 –Diesel Engines- and L1 certifications) gives me insights into the abyss of the workings of this TDI engine. The V6 TDI that we all here have in our cayenne diesel is actually a VW/Audi product.

As a prelude to what I am going to say and in summary for those that do not want to read my lengthy monologue, I have it black and white from my Porsche Dealer in Germany –Stuttgart Flughafen Dealer—that the noise that I had recorded from my TDI Cayenne upon startup is indeed NOT NORMAL, and should “in accordance to my service reps. own words: Never be hear”.

My company does extensive work in Germany and in the states. I own a 1997 993 Indish Rot Bi-Turbo, a 1991 964 Carrera 4, Indish Rot and a 1967 911S Bahia Rot of which some of these cars are in the care of the Flughafen Stuttgart Porsche Dealership.

In the states, I just recently purchased a 14 Cayenne in White. At the time of purchase the vehicle had some 65k miles on it and was sold by the MAG dealership in Columbus, OH. Within two months of driving, and having accumulated during that time some 3-5k miles, I noticed that the vehicle from time to time made a timing chain noise, much similar to my 2011 ML 350 Mercedes Bluetec. Due to the many problems I had with the Bluetec, I immediately knew that this was not a GOOD Sign. Nonetheless, I hoped for the better and knew that I had unlimited MILEAGE warranty on the rig.

At the first oil change, I already notified the service rep. at MAG that the vehicle was making the timing chain slapping noise indicative of a failed hydraulic timing chain tensioner. My dealer and rep. did not want to have anything to do with my complaint and just shrugged the shoulders, stating that no check engine light is equal to no problem. As anybody can think, this did not sit well with me. I approached two other dealership during my many extensive drives and they too, gave me the silliest and unprofessional remarks concerning the problem.

Fast forward, the timing chain rattle/slapping has gotten progressively worse. I now own the car for less than a 11 months, have accumulated 20k miles and have to endure this harsh unpleasant noise almost every second startup.

The noise is not what disturbs me, but what is happening in reality behind the scenes. What do I mean by that? Simply put, the V6 Audi/VW Diesel is an impressive fuel sipping, torquey mule, but has one major design flaw: It has dependent upon the build year up to 4 timing chains. Yes, you heard that correctly: 4 timing chains. The oil pump itself is driven by a dedicated chain drive!

There are timing chain guides and tensioners for the chains. The guides are either made of metal and are coated with a nylon compound or made entirely from a non-metal material. The rattle/slapping upon start-up doesn’t cause the chain to loose tension exactly because the driver sprocket on the crank or intermediate driven gear sprocket keep the tension in the pulling direction, but the slapping happens on the loose, tension-less side of the assembly. Think of it like your ten speed on your bike. If you pedal, the top of the chain stays tight and the bottom is relaxed or firm. Why is it firm? The spring loaded tensioner/ derailleur keeps the chain from slacking. In the case of the hydraulic/oil tensioner, this is no longer happening in our cars, which can have catastrophic failure in case the chain links do not seat properly on the sprockets and thus causes the timing chain to jump, thus potentially risking a valve and piston collision.

The slapping and rattling causes also excessive wear in the coated chain guides along with potentially breaking “all-plastic/nylon” guides. Where does all that end up? It ends up in the oil pan and contaminates the engine more and more, damaging the rest of the engine, while the problem persists.

For those of us that start their engines more than twice a day, the wear and risk increases exponentially.

Here comes the technical aspect of things:

The timing chain tensioner is comprised of a spring, check valve, in some instances a locking mechanism, etc. (I am not sure if this audi engine has a locking mechanism –the tensioner extens and locks, every time it extens a set amount, similar to a ratchet mechanism). In our engines, the check valves, maintaining oil pressure (peak pressure from the oiling mechanisms operation), are no longer holding pressure.

Why is this the case? The oil has been contaminated for too long or the oil was just the wrong oil grade, or the engine management, ECU Programming, is not adequate.

Well, I would recommend using T-6 Engine Oil in these sumps, but as I have done –following dealer recommended oil change criteria—I let the dealer put into it, what they “think” is the correct oil.

The oil change interval of 3k miles, that the MAG dealer forced upon me, is reasonable.

Here is now the kicker though: All of our TDIs have a major ECU programming fault /design flaw. What do I mean by that? Forget the Diesel Gate Scandal and focus on the technology here. Our Prosche Diesel TDI engine has an oxidizer, DPF and SCR exhaust assembly. The DPF is the diesel particulate filter, the SCR is NOx catalyst and so on. The DPF/oxidizer traps soot particles in it during the normal operation of the diesel engine. When the DPF Pressure Differential Sensor, which is reading in front and after the DPF the exhaust back pressure , senses a too high discrepancy from upstream to downstream, the engine goes into an ACTIVE DPF REGENERATION MODE. What does an ACTIVE Diesel Particulate Filter Regeneration mean? The engine programming should have recorded a “high” trigger value and have stored such in the ECU. Once the engine reaches operating temperature the next time or within that “drive cycle” for some pre-defined mileage travelling over approximately 50 MPG, the engine starts its regeneration—the engine starts running rich—more fuel is injected—the boost is increased, injection timing altered, valve timing altered, the cooling fans are running, when they really should not.

All of this combines to increase the in-cylinder combustion temperature from a normal highway cruising temperature of 300-400 C to almost 800 C during the same driving condition. That high temperature in the combustion chamber, causes the exhaust upstream the DPF to heat up extensively.

All of this puts tremendous load and stress on the valves, pistons, turbocharger and exhaust components! The engine oil also increases a good 20C during this process. Diesel run sooty, we all know that, that is why the engine oil is immediately black again after an oil change—there is so much soot and carbon suspended in the oil and metal surfaces within the block, that the fresh oil just turns black again within minutes of an oil change.

That high carbo/soot content in the oil clumps and interlinks when the diesel engine reaches these high Active Regeneration temperatures. These chains of molecules then build-up around components like piston compression rings, piston oil control rings, “chain tensioner check valves” etc. Here lies the fundamental problem—the engine management layout/mapping.

These EU Diesel cars –Mercedes Bluetecs are really the worst--- are designed and programmed to rely heavily on PASSIVE REGENERATION. Passive Regeneration occurs when engines are operated in the x> 3000 rpm range and under X>50% load, for an extensive period of time. You have high CFM throughput (high engine rpm), higher temperatures (max only 470 C) for say 20 minutes of driving: the Soot just vaporized itself along with being properly exhausted/vented from the DPF and SCR.

In Europe these diesel engines from Mercedes and VW /Audi do not experience the same failures or problems we experience in the US. Our speed limits and cruising speeds almost entirely prevent the exhaust from passively regenerating.

Mercedes Bluetec Sprinters in the US also don’t have any of the problems that their cousins the ML or GL 350 Bluetec from 2010 through 2014 had. The Sprinter cargo van operates at 70 MPG at around 3k to 3.5k engine rpm with an above 50% engine load. There the exhaust system passively regenerates.

The SCR and Urea injection even further compounds the problem. That is why the Diesel Gate Scandal even occurred. Porsche, VW and Audi (I say Mercedes too), who knows about BMW (It is to be noted that Bosch supplies all of them with ECUs and sensors, food for thought), eliminated the injection of UREA or DEF (Diesel Exhaust Fluid) below a threshold of ambient environment temperatures. Why you ask? Well simply the exhaust temperature downstream the urea injection nozzle would have been too cold for the urea to fully evaporate. If the DEF / UREA does not fully evaporate in the exhaust stream, within the SCR or selective catalytic reduction filter, then the DEF will crystalize therein and cause the filter to plug up. The engine management system however is not smart enough though to realize when and at what point the SCR filter is getting plugged (no differential sensors there, only temp sensors and upstream and downstream of the SCR NOx sensors).

I have not had any NOx sensor go bad on the Cayenne yet, however on my 2011 Bluetec, I had at least six NOx sensors installed over a course of 120 k miles. The AdBlue, also called DEF or Diesel Exhaust Fluid Tank/Reservoir in the ML 350 Bluetec also failed twice.

Let’s backtrack here:

The active regeneration method/mode of programming also compounds the life and regen cycle of the DPF (diesel particulate filter). When the engine runs hot during the active regeneration, the oil gets approximately 20 C hotter, overall. The oil getting squirted onto the bottom of the pistons by means of the oilers causes the oil to evaporate during said cycle---yes oil can evaporate. The oil gets then drawn and vented from the crank case ventilation into the upstream of the turbocharger cold air stream (vacuum side of the turbocharger in between the air filter box and the compressor housing inlet of the turbocharger). That is why you see oil laying around the turbocharger air inlet grommet. The more often the engine goes into an active regeneration, the more oil you have in the turbocharger, intake, combustion chamber.

Because you are now pushing oil into the combustion chamber, the combustion process and exhaust gasses get dirtier (sootier) and therefore cause the DPF to plug up even sooner then before.

Mercedes recommends explicitly in the owner’s manual of the 350 ML Bluetec to drive every 600 miles for an extensive period of 20 minutes at HIGHWAY speeds ( MB is hoping on passive regeneration).

In short, our diesels are programmed to self-destruct! Class Action Diesel Engine Failure Lawsuit?

In the meantime, I would recommend driving the Cayenne or any EU diesel (especially the Bluetec) in lower gears, when not on the Highway to keep the exhaust temp and exhaust CFM (cubic feet per minute) high to invoke passive regeneration.

On the Mercedes Star Diagnostic System the ECU can be read and determined how many miles the vehicle has driven since the last active regeneration.

In the US a good mileage number would be 2000 miles! Keep in mind though the ECU Check Engine Light or CEL or MIL only comes on if two active regenerations occurred within a 150 mile driving interval. That is ridiculous!

I am currently working at getting either the engine replaced or the timing chains, timing chain tensioners and timing chain guides replaced ---under my Porsche Certified Pre-Owned Warranty. My recommendation is that you do TOO.

P.S.: The Porsche and Mercedes Dealers in OHIO, that I have been to so far, are all inadequately trained or equipped or just want to sell Porsche drivers as IDIOTS, I included, because they think they can get away with it.

chsu74

^ I currently also own a GL320 and CD so frustrations are shared.

The OM642 is known for plugging up PDFs and runs hot with the engine tray killing oil cooler seals. I am currently fighting a bank 2 intake manifold valve closed P2007 code. Tore the motor all the way down and replaced the oil cooler seals again even though it was done 2-3 years ago under CPO warranty. Still the code came back after 3-400 miles of driving. Folks have had luck deleting PDG/EGR/SCR with the motor and it is much happier. You can buy a scan guage to show PDF accumulation levels and trigger passive regen driving around in a lower gear to get above 3K RPM.

I don't know much about the VW/Audi TDI motors yet but thought they had two generations. The US Audi/Cayenne diesel motors only has 3 chain and earlier gen had more chains in earlier Tourag TDI models was bought back.

In short, these diesel motors are designed to use a different oil for a long healthy life. However, all these emission components forces a lower ash producing oil to be used which compromises reliability and longevity. Yeah.. more frequent oil changes help for sure.

pepperpepper

Thanks for the detailed response HGR. As I stated above, I believe that a check valve in my timing chain assembly has failed and can be attributed to the chain noise that I am hearing (it seems like you are corroborating my suspicions). I have broached the issue with my dealership multiple times and the best response I've gotten out of them was that they were able to reproduce the issue in multiple other Cayenne Diesels. That, in their minds, means that the sound is normal.

They also claim to have called the PCNA "Tech Line" at my behest and they claim that PCNA reinforced their position that the timing chain noise is normal. I also called PCNA myself in an attempt to get their help with my dealership's reluctance to help me. I spoke with a customer service representative who was rude to me to the point of being combative, he actually yelled at me several times during the call. He insisted that whatever the dealership determined was the final word on the subject, and that PCNA absolutely refuses to intervene in disputes between owners and dealerships.

Now, I happen to believe that there is something wrong with my car and that eventually there will be a failure of the chain tensioner and/or the chain itself and then we will have a serious problem. The only thing I can hope is that my car will still be under warranty at the time of failure and that PCNA will have to buy me a new engine.

One thing I have figured out so far is that, for whatever reason, PCNA and my dealership both seem to think it's appropriate to treat me as though I am some sort of second class citizen. I have had issues with attempting to get my dealer to attend to warranty issues on my vehicle multiple times and when I asked them why they were reticent to address a problem I was having the Service Manager told me that PCNA doesn't pay them much to do warranty work and therefore it's not a priority for them. The last time I had the Cayenne in for service, the dealership had it sitting there for almost a month for reasons I honestly don't understand.

So, I'm faced with a quandary. I really do like my Cayenne, it's by far the best, most versatile vehicle I've ever owned. I would really like to keep it for as long as it is practical. But my dealership and PCNA's behavior toward me is making it very difficult to see the point in keeping it if they won't fix the vehicle when it's broken. I understand that the dealership (and many people in our clubs and forums) believe that since I don't have a sports car with a flat six that I'm some sort of heretic. But just because I don't have one now, doesn't mean I won't in the future (unless they keep treating me like crap).

Anyway, if you're able to get any traction with getting your timing chain problem addressed by your dealership or PCNA, please let me know. I will be going in sometime in the next couple weeks to have the whole mechanism for the tailgate replaced, as soon as the parts come in from Germany. I will be complaining again about my tensioner noise and I'd love to have something to support my argument when I go.

Eskimo1

HGR, thanks for lending your expertise to the forum, but there's something about your below statement that doesn't add up based on my observations.

During a regen, yes, the #3 and #4 EGT probes get much hotter than normal.. 1250°F vs. the normal 500-700. However, to say the combustion chamber temps get that high - the logs just don't support it. The #1 EGT probe (pre-turbo) reports hotter than normal, sometimes 1000-1100°F during somewhat normal driving, but not 800°C, which I only ever see on an extended WOT run. In fact, the post-turbo EGT doesn't get very hot either. However, #3 & #4 (in the DPF area) are what get hot enough to burn off the collected soot.

I'd imagine the EGR system does more to kill the oil than a regen does..

HGR

Hello there--everything I have been saying adds perfectly up. Here the CDI regeneraton observation from my ML 350 Bluetec using the DAS/XENTRY system from Mercedes Benz. The regeneration process --active regeneration-- is the same for the MB CDI or the Audi/Porsche CDI--all the components and modules are supplied from BOSCH.

If the upstream turbocharger temp would not increase from the combustion injection and timing, etc. then the temp downstream the turbocharger would not increase enought to cause an ignition of the soot particles.

The EGR has nothing directly to do with the oil temps increasing to the point where oil starts to evaporate/soot particles start to clump.

The active regeneration, as shown by the pic, can only occurr between 2000 rpm and 3000 rpm--so no WOT condition pertaining to the temp values.

........

HGR

Here the timing chain noise--audibly during a warm engine start up.

HGR

Here the letter from the Porsche Dealership in DE/Germany

that services my 993 bi-turbo and 964 carrera 4, upon hearing my audio file.

HGR

I typed this up on the 1st of Feb. After submitting it, it still had not showed up in this thread nor in my USER POSTS. I honestly figured it was lost.

Since this state continued until the 5th of Feb. I pretty much thought, to having been forced by this portal's programming and bugginess to retype everything, hence two detailed posts about the timing chain issue.

Now, I come to find out that it actually posted, too---did a "PROCLAIMED ADMIN" pull the strings here, for no reason........

Eskimo1

My comment about EGR is that it really kills the oil by reintroducing the exhaust gas into the intake, not that it affects temps.

M2-6MT

My 2015 CD with 41K miles just started this chain rattle noise at cold starts. Not every time but recently noticed it few times. I wonder if the emission fix have caused a premature wear on these engines.

hotrod2448

Additional info, I have a rattle on startup sometimes. I assumed it was the timing chain noise discussed in this thread but, my dealer says it is a lifter that has bled down and that this is common on the diesel and the hybrid. Thinking it through this does make sense (I don't see the correlation with diesel and the hybrid doing it but, the noise does fit) but, still does not seem to be normal operation. Listening to it closely the last few days I can hear the rattle at start up for 2 seconds it then goes away but, there is a lifter tick I can hear that then goes away maybe 3 seconds after the rattle ends. Taking it in this Friday so hopefully there will be something that comes from that.