Engine knocking noise - Cayenne S 4.5

[deilenberger]

I think 'common' is perhaps not accurate. It's happened, People have reported this happening, but dunno how much of the reports I've seen are multiple reports of the same failure. Offhand - I can recall 3 where they appeared to be unique vehicles (not the same owner complaining on multiple forums in multiple posts.)

I suspect the rumor might be that the cylinder wall coating wasn't up to the job... I believe Porsche is using nicasil or alusil on the aluminum cylinder walls. BMW had problems with the nicasil coating on early V8's due to high sulphur content in the fuel. They later went to Alusil and the problems went away.

IIRC Alusil is an etched surface created by etching away the soft bits of the aluminum cylinder wall, leaving silicon crystals behind as the wear surface. Nicasil is an evaporated coating of metals - only microns thick, but very hard. FWIW - there are BMW motorcycles out there from the mid '80's that used Nikasil cylinders - running around with 300k+ miles on them, and the engines have never been touched.

Did a bit of looking - the Cayenne V8 uses Alusil: http://en.wikipedia.org/wiki/Alusil http://www.kspg-ag.de/index.php?fid=209&qid=&qpage=0〈=3&query=cayenne

Other Porsches may use Nikasil: http://en.wikipedia.org/wiki/Nikasil

[mcbit500]

To be accurate the entire block is cast from the alloy Alusil in a low pressure die-casting process. The cylinder honing process exposes the primary silicon crystals which are distributed throughout the alloy and as such no additional hardening is necessary. My own feeling is that since the majority of these occurences seem to occur in isolated single cylinders that the problem may actually be due to the introduction of foreign bodies through the spark plug orifice.

[RFM]

I agree concerning the allu./silic. mix in the entire engine block, some of the water cooled flat six engines are suffering with the same issue. What was remarkable about the problem is that it always was one of the front cylinders showed that issue, not random, both the V8, mostly Turbo, and the flat six. I have seen about eight or nine of these till 2009 when i retired. However, i would be surprised if it was ever caused by foreign bodies. I think they know more on this issue in Stuttgart.

[wvicary]

I have only personally seen one of these failures and it happened after the customer ran the engine so low on oil that the low oil pressure warning light was coming on and the low oil level warning had been on for months before hand.

[Larry735dn1]

Hi again, Season's Greetings!

Has anyone had any positive interaction with Porsche re these problems? In my case Porsche has been uncooperative despite the scoring happening shortly after the car came back from Porsche main service (they had not filled enough oil - the dipstick was dry, the oil pressure monitor was failed -they did replace this free of charge, and they had left air locks in the cooling system following the change of coolant pipes in the "V").. Nothing to do with them, they say... Have not found an acceptable solution yet. The car runs fine except for the knocking at lower rev's but I'd like to find a reasonable solution. I clearly think the is something Porsche should have sorted out under goodwill and am still inclined to sue them.

Any good news anywhere?

[911gt700]

I recently purchased a 2008 Cayenne turbo from the east coast and noticing the same sound at idle. It has 45K miles so still under warranty but my question is it has extensive power package from Evoms (there 700 turbo upgrade kit) would the porsche dealer or porsche usa have a problem with that even though under warranty?

[mudman2]

no question it would void the warranty

[royxaxa]

I too have the knocking noise. not as loud though. i thought it was quite common. at least most of the CTT i saw had this issue. more or less. :(

[911gt700]

no question it would void the warranty

I figured. Thanks

Being its under warranty for the moment would it be wise to replace everything back to stock then stop by local Porsche dealership? I just don't want to do all the work for nothing.

[Doug Perkins]

i have rebuilt 7 of theese engines in the last 7 months. there is a definitte problem with cam followers in theese engines, but this is not the main problem with the engines. The cylender walls become scuffed by poor quality pistons from factory. I have as mentioned have rebuilt severall of theese engines with no problems, with much less cost than Porsche,,, 10 grand our end...20 or more from Porsche

. ..

[SA321]

are there cam followers on Turbo? what is the sound they produce?

[Loren]

are there cam followers on Turbo? what is the sound they produce?

32 of them on the Cayenne V8 engine.

[SA321]

o, tappets. got it. so what could go wrong with them so that they can start making knocking noise? I am now going to ask a very stupid question. Idle RPM is 560-600 so 10 piston movements/second. so how could it be a scored cilinder if the knocking sound that I have (and most other people with similar problem) is at much lower rate 120-180/minute or thereabouts. what could it possibly be? my knocking is in the area of cyl 5-6 (i have 4.8 Turbo)

Edited March 7, 2012 by SA321

[pkurzenhauser]

I'm new to the Renntech forum as a poster, but have used it for looking up stuff. Unfortunately, I also have experienced the cylinder scoring problem in my 2008 Cayenne S, with less than 48,000 miles on it. Here are the details:

Back in January, my wife noted that her car would run rough once in awhile, but when I drove it, I didn't notice the problem. In February, it started misfiring significantly, and the check engine light came on, flashing, which the owner's manual says to stop driving it as soon as possible because the catalytic converter can be damaged. She was just pulling into the driveway when it came on flashing. Note that the warranty on this car (4 years/48,000 miles) ran out of time almost a year ago, even though it was still under the mileage limit. The car has been maintained by Porsche dealers at all service intervals.

So, I took it to my local Mercedes and foreign car shop in Great Falls because that's only 2 miles away (the CEL was out when I restarted the car, but came on about a mile down the road). They read the trouble codes, found that the #5 and #6 cylinders were misfiring, pulled the plugs and saw that they were carbon fouled, and thought that the coil packs were bad. Since they were only $60 each, I agreed to try that. They also replaced all the plugs ($25 each, ouch). They also found that the air filter on the left side was not correctly installed, letting air get past the filter at the bottom edge, which they then correctly installed (the filter had been changed by the Porsche dealer in my area 10 months before when I had it serviced). I drove it for a week and it started misfiring again. Back to the shop. They pulled the codes, saw #5 misfiring, and pulled all 8 plugs and saw that most of them were fouled again. At this point, they said I should take it to the Porsche dealer, so I called a tow truck and had it taken to Tysons Porsche.

The dealer mechanics read the codes, found misfiring on #5, and intermittently on others, and all the plugs were carbon fouled (it had not been driven more than 100 miles since the plugs were replaced). They contacted "Porsche Tech" who advised them to try several things, including replacing the injectors. The mechanic working on my car thought that was excessive, and I agreed. If one or two cylinders had fouled plugs, I might have agreed to replace just those injectors, but all eight shouldn't be bad at the same time. No, something else was going on. The mechanic recommended doing the BG-44 treatment, including spraying into the tops of the cylinders through the spark plug holes, and he scraped the carbon off the piston tops as best he could (through the spark plug hole). He drove it and it was running normally, but still didn't seem quite right, but the service manager suggested I take the car and drive it for a week, including some spirited highway driving to clean out whatever deposits remained, and report back to him. I did that, but by the end of the week, it started misfiring again.

After it started misfiring again, I pulled the spark plugs and found that #5 was not just fouled, but OIL fouled. The other plugs had more carbon than I would expect for new and recently-cleaned plugs, but not too bad. Now suspecting a major engine problem, I cleaned #5 and swapped it with another plug and continued driving it a few more days. It then started misfiring again, and again #5 was oil fouled, but this time, I pulled out my compression tester and measured the compression. I measured around 260 psi on most of the cylinders, about 250 on #6, and only 230 on #5, which was more than 10% lower than the average.

Lemme repeat that: about 260 psi was the AVERAGE, which would be the result of almost 18:1 compression ratio!! That's diesel compression territory. I thought my gauge might be inaccurate, but not that far off. I went back to my local indy shop and asked the owner's advice. He was very surprised at the measured CR, so he lent me his Snap-On compression tester to measure again. With his gauge I measured an average of 275 psi! Is it possible that carbon fouling in the cylinder head/piston tops could raise the CR that high? I suppose it's possible, but extremely unusual.

I then went online and searched for this problem, and found multiple references to scored cylinders and people needing engines replaced at low mileages, particularly on the Renntech Porsche forum. It appeared from that reading that some engines have a defect in the engine block casting that causes one or more cylinders to score, usually #5. Keep in mind that these are aluminum blocks and cylinders which I understand are Alusil and not rebuildable except by specialty shops.

I took the car back to the Porsche dealer and told them about the unusually high compression measurements and oil fouling on #5. I suggested they do a borescope, based on the internet info I had discovered. They did so, and found scoring in the #5 cylinder. They reported that to Porsche Tech, and said they would work with Porsche to get me a new engine as a goodwill replacement. After a month of processing, Porsche agreed to provide a remanufactured engine, but it took another month and an half to get it, and then several more weeks to get it installed because the special "engine holder" was in use on another Cayenne that had its engine damaged, supposedly for a different reason. Anyway, I finally got the car back at the end of May.

I had a long discussion with the service manager, whom I know from the Porsche Club around here. He said they had replaced 5 Cayenne engines that had the same problem as mine, and in those cases it was the #5 cylinder that scored. The scoring was always on 6-o'clock position of the cylinder on the left bank, which is where the piston presses when it is heading down on the power stroke. He and I discussed the likelihood that the block had a defect in manufacturing due to the molten alloy cooling too far before it fully filled the casting molds (#5 is the left front cylinder), but he didn't have any more info from Porsche than I looked up on the internet. I was thinking of keeping the old engine for parts, and also to pull the head off and see what happened in there (I'm an engineer and analyst), so I asked what the core charge on the old engine was, and he said (wait for it) $30,000!! What?!? The core charge was actually MORE than the price of the remanufactured engine, which was "only" $25,000!!! The only conclusion I can draw from this is that Porsche does not want anyone outside the factory to take apart and figure out what is wrong with these engines, and start a recall campaign or class action suit.

To wind up this story, I still have unanswered questions (why the scoring, why the extremely high CR), and I guess I won't get them answered anytime soon. Even though Porsche supplied a replacement engine, and the dealer contributed something to the goodwill replacement, it still cost me $6000 out of pocket for the initial work at my local indy ($700) and at the dealer to pay for the labor to troubleshoot and then install the new engine. At least it comes with a 2-year warranty, so I guess that's worth something, but I have to say that this never should have happened in the first place. It certainly appears that there is a serious latent defect in a substantial number of these engines.

Note, the Porsche V-6 and V-8 engines used in the Cayenne are also used in the Panamera sport sedan, so if you are considering any of those, caveat emptor! And, I wouldn't buy a Cayenne again, except from a Porsche dealer WITH the Porsche used car extended warranty. In fact, this experience makes me much less favorably inclined to buy any Porsche model in the future, including the 911's because they use the same technology. Too bad, because my previous experiences with Porsches of several descriptions were very positive, and I still have a 1973 911.

I also should note that the Consumer Reports reliability ratings on the Cayenne that came out in January 2012 rated the Cayenne "much worse than average" in many categories, which was a substantial drop compared to the ratings in 2010 when I bought the car.

Buyer beware!

[trady]

Hello

Have read through this tread, and I have the same problem - actually 4 cylinders are gone on my 06 Cayenne S. I was wondering if you have any tips (preferably in Europe) of shops you could either rebuild or better sort out 93m3 cylinders (+0,5mm from the originals). I really cant buy a new engine, so looking for other "innovative" solutions..

thanks,

(from germany of all places..)

[ActiveLife]

Sorry to bring back an older thread....

I was an early poster to this thread back in May 2011 when I purchased my first 05 CS. At that time there wasn't any issues with it and I was loving every moment of ownership... HOWEVER, now almost 2 years later, my engine has the knocking noise 88k miles.

Maybe there is a different thread that I missed that goes into more detail about the issue? I would rather not replace the engine but that seems to be the only solution I'm reading about. My wife wants to walk away from the car and never go back to Porsche... but I don't want to give up so easily.

Can this be a "re-hone" and rebuild fix?

The noise is embarrassing to say the least, it sounds like it’s a diesel. It makes me cringe with the feeling the engine is just going to give up.

Any thoughts or knowledge?

[Andrei Marton]

I ran into this problem a few times. I have 4 friends with V8 Cayennes , wich had their engine replaced. 2 where turbo's and 2 where S's. I must mention that these are all V8 4.8 engines, so we are talking about the 957 model.

In every case the issue was solved by relplacing the engine.

Still, one of them had the same problem again with the new engine, Cayenne S, BUT, only because he was a moron, and after 30.000km he was still runing the original oil. So, no oil and filter change in 30.000km.

Funny thing, is that know this problem with these engines, i bought one of these cars. the other "S". I had full service history, knew the guy, knew the problem. Still, having a close relationship with my Porsche dealer, asked about this issue, they told me that this problem, appears, at least on 4.8 engines, when you do the following:

- miss the oil change interval

- use bad oil ( i use only Mobil 1 0W-40 full synthetic) - althought i am very tempted on Motul. BUT, i addmit, i'm Affraid.

- drive with the engine cold in winter

- hard on the gas pedal without the engine oil hot - 90 degrees Celsius.

- also mentioned about performance fuels: i NEVER use 100 octane fuels. Only 95 or max 98.

Also the dealer mentioned that after 2010 , they changed the alloy the engeines where made, so i should not encounter these problems anymore.

So, i only drive away after the water temp reaches at least 50 degrees celsius, and hard on gas, only at 90 degrees oil temp.

[simong0201]

I recently bought a Cayenne Lumma wide body 4.5s and guess what? It's developed that knocking noise we all talk about. Porsche suguest another engine. That sounds a bout right. 12000 car needing a 10000 engine replacement. Not sure I will get my money back on this one haha. I have just had major service and he said it was crack in cylinder. The ticking I can cope with but it looses power quite alot when warm. I was hoping there would be some kind of filler you could pump into system like on radiators. That goes to show my mechanical capabilities. The other noise is a knocking down at the right hand side, like a track rod or something. The **** who serviced it said they had put wrong spacers in and they were not sitting correctly on hub. BOLLOCKS. If that were case why would it not make noise all the time. It seems to make it when you set off quickly. Any ideas. My only thought was that we all met up and built one good Cayenne out of all of ours? Let me know if any ideas about knocking. Good luck with all your cars. Simon. God bless. P.S I only run mine on high octane expensive fuel and oil and its gets through alot of both. At moment I am getting 11mpg. Good oil should always be used, but should I go back to normal cheap octane?

Edited January 13, 2014 by simong0201

[roach2012]

Same situation here Cylinder # 5

Trady have you found any innovative solutions that work or at least seem promising ?

To the best of my quite limited understanding, the whole block is Alu-Sil, so re-honing would be a simple job (to those who can).

[MajidSyed01]

Hi,

I have a 2004 Porsche Cayenne S v8 4.5l 200000 km in Calgary, Alberta - Canada and have the same issue with the knocking noise. The knock is coming from the 8th cylinder, I have checked / swapped knocking sensors, replaced crankshaft followers, spark plugs and ignition coils as well but no luck. Everything online has been pointing to a scored cylinder; have anyone been able to get it fixed by any means other than replacing the whole motor?

Any recommendations to who can actually rebuilt the engine in Alberta, Canada?

Thanks & Cheers,

Syed

Edited April 24, 2014 by MajidSyed01

[bekks]

Bringing up this thread again.

 

I have a new to me '05 Cayenne S with 200,000 km on it. It is noticeably "ticking" away. I don't have any maintenance history, but it "looks" well cared for. 

 

My questions is, has anyone ever NOT replaced the engine? Mine is not consuming oil, I notice no driveability issues. It's just noisy. The cost of an engine replacement will be well over the price I paid for the vehicle, so I intend to keep driving it. Has anyone had a major failure after their ticking started?

[ekstroemtj]

Hi . Just my experience. The ticking went from a little bit to very loud now. Depends which rpm your are driving. My S started to use oil. But still not as much

As my turbo engine. Lol. As oil consumption increase the plug in the effected cylinder gets bad because of burned oil I guess. Have to change it frequently. From time to time I have a check engine light.  Codes are pointing to a problem with O2 sensors what I believe is related with the scored cylinder too. Burning oil effecting the reading of the sensors I believe

 Besides the noise and the oil consumption the engine works well. But that's not a must be. I read some scored cylinders ending up in a fatal engine failure. 

I am still thinking about a overhaul

. Here in Europe we have companies doing a good job for 3500 Eur.

Good luck

 

[TDHeller]

Here too looking for any repair info on this issue.

I just bought an 08 Cayenne from an indy dealer -As is No Warranty - They wouldn't offer one.

Engine ran fine on test drive of about 10 miles - no problems evident anywhere - vehicle looks factory fresh from top to bottom.

Drove about 65 miles home with only one large puff of blue smoke on launch from light- ran fine save a slight miss at times.

Next day changed oil Mobil 1 0w40 with Mahle filter and vehicle close inspection - looks better than suspected everywhere.

Following day drove around town 20 miles or so low RPMs and city traffic developed a serious miss and performance issues.

Checked and replaced coils (BERU) and plugs (Bosch) before extended drive following day - after 60 miles developed same miss and heavy oil consumption (#8 & #1 cyls.). Parked it and boroscoped  Cylinder 8 and found scoring from photo attached. also only 150 psi compression on 3rd hit.  

Looking for an effective solution short of total engine replacement. Anyone have luck with re-honing cyls and re ring engines here?

[JFP in PA]

Welcome to RennTech

 

Unfortunately, you are not going to be able to hone out that amount of liner damage, and even if you could, the pistons would be so loose in the bores you would have even larger issues.

[ekstroemtj]

19 hours ago, TDHeller said:

Here too looking for any repair info on this issue.

I just bought an 08 Cayenne from an indy dealer -As is No Warranty - They wouldn't offer one.

Engine ran fine on test drive of about 10 miles - no problems evident anywhere - vehicle looks factory fresh from top to bottom.

Drove about 65 miles home with only one large puff of blue smoke on launch from light- ran fine save a slight miss at times.

Next day changed oil Mobil 1 0w40 with Mahle filter and vehicle close inspection - looks better than suspected everywhere.

Following day drove around town 20 miles or so low RPMs and city traffic developed a serious miss and performance issues.

Checked and replaced coils (BERU) and plugs (Bosch) before extended drive following day - after 60 miles developed same miss and heavy oil consumption (#8 & #1 cyls.). Parked it and boroscoped  Cylinder 8 and found scoring from photo attached. also only 150 psi compression on 3rd hit.  

Looking for an effective solution short of total engine replacement. Anyone have luck with re-honing cyls and re ring engines here?

 

 

Feel very sorry to hear this. Very bad luck.

wondering you didn’t hear anything during test drive. Surprised it happens so suddenly. No extreme driving, no extreme driving.  

Maybe they have used a extremely heavy oil to push down the knocking noise when u had your test drive.

which engine is it? How many miles?

Edited October 12, 2017 by ekstroemtj