Engine knocking noise - Cayenne S 4.5

[Larry735dn1]

Hi All,

Have followed the forum occasionally and now have a question re a current problem ..

My wife's Porsche Cayenne S - 2004 with 65k miles - owned from new - has developed an engine noise which initially sounded like valve ticking, but is now a more distinct engine knock. The symptom is a distinct ticking or knocking noise on every second rev (car idles very low at some 580 rpm at moment, giving some 290 knocks/minute. The knocking disappears at higher revs (> 1,500-2,000) but does not go away entirely when engine warms up. The knock appear to come from the right hand top area, but couldn't rule out "piston slap". Other than this the car runs smooth with full power and no misfire, no smoke, oil and coolant fine. Last year we had to replace the silly coolant pipes in the V of the engine after the plastic ones cracked with loss of coolant, and Porsche also did a full service at the time. Car came back from service very low in oil (about min on dipstick) and with a faulty oil pressure / temp sensor, which we discovered a little later.

Wife took the car to Porsche outside London, where they did some simple diagnostic (without the use of endoscope or camera) and declared that one of the cylinders was scored and that a new engine was the prescription - hand over £14k plus VAT please.. Not fun at all, and the diagnosis seem questionable...how can you verify scoring in the cylinder by peering through a small spark plug hole without an endoscope...

Took it to another dealer for a listen-to, and the technician there thought it was likely top related (Cam, valve bucket..), whereas the service manager suggested piston slap. Car going back tomorrow for some more diagnostic, perhaps the cam cover has to come off... So the meter is running..

I wonder if in your aggregate wisdom you would have some advice for me. I've heard everything from Cam / valve buckets through water pump to piston slap, but given the symptoms is one or the other more likely? I certainly intend to pursue the issue with Porsche UK to try to get some goodwill contribution (not easy when car is 7 years old and out of warranty. The car had major cooling pipe replacement and associated engine oil sensor issues less than a year and 5k miles ago at the main dealer (Porsche in their wisdom used plastic coolant pipes in the V of the V8, and these pipes are prone to cracking which happened - as described in detail elsewhere on the forum.

If worst case is confirmed, where can one source a good engine, given that a new engine is gong to be uneconomical relative to the cars residual value...

Thanks for your pointers..

[bigbuzuki]

At minimum they should insert a borescope into the cylinders with plugs removed to confirm the alleged scoring.

Even if you have scoring, why change the engine if you have no other issues besides the ticking noise? If the problem gets worse your still up for a replacement engine anyway.

Seems like you are not alone on this one. Some links below with similar symptons.

http://forums.rennlist.com/rennforums/porsche-cayenne-forum/567200-cayenne-engine-replacement.html

http://www.6speedonline.com/forums/cayenne/158047-ticking-noise-normal.html

Edited April 21, 2011 by bigbuzuki

[RFM]

Probably cylinder wall damage, some M96 engines (flat 6) also suffer with the same issue, they use the same allusil metal composition, 69% allu.-31% silic. Cayenne rebuild V8 engines are also available as a naked bloc, which means without cylinder heads, injection, etc. So look good which ultimately is the cheapest. Good luck.

[Larry735dn1]

Thanks both for your response. It seems that in most cases like this a scored cylinder has shown up. However, several experienced guys (Indys) I've shown the car to are pointing to a Cam or valve bucket related issue. The knock disappear over 1500 - 2000 rpm, which could suggest that oil pressure on idle isn't sufficient to get enough oil into this area (as rpm increase so does the oil pressure)..?? Or is that wishful thinking... Have you seen the Cam area being the cause of something like this?

I'm in London where everything is a rip-off (except the Pound at the moment)... are there cheaper sources for a short engine on the Continent (they quoted £16,800, which is about US$ 28,000!! Pretty much what the residual value of the car is and not an option... And do these alusil blocks / cylinders not have linings at all and therefore the whole block must be replaced?

Thanks

Edited April 21, 2011 by Larry735dn1

[wvicary]

I had a customers engine make a noise which I thought was a failing valve lifter which went away off idle but as they put more milage on the vehicle the noise was constant. I replaced the lifters for that bank and it didn't help so we assumed it was a failing piston/damaged cylinder wall. I did use a scope to inspect the cylinder wall but could see no damage, engine ran fine and used no oil. As the cost of the engine would exceed the vehicle value it was determined they would continue to operate the unit and it's been over a year and the nothing has changed.

Before all this happened, the vehicle did lose a good portion of it's engine oil due to the PCV valve freezing up and the customer continued to drive the vehicle for several weeks before bringing it in for service. It had all the lifters rattling by then and I only recovered approx 3 litre of oil when I drained the crankcase. And Yes, several warning lights were on but they choose to ignore them.

[RFM]

I would contact an O.P.C. in Belgium which are probably the cheapest in West-Europe for parts and repair, the nearest to you with a good reputation is in Sint-Martens-Latem (Carrera Motors +32 9 2822422)

[Larry735dn1]

Thanks - will do over Easter... do you have any experience with this company...AWS GmbH, Auf'm Rottland 5, 57577 Hamm/Sieg...they apparently have a used engine with 76k km...risky business perhaps..

[RFM]

I have no experience with the company from Hamm, regards the risk, there are not so often engines with this problem. Whatsoever there will be always a degree of risk, also exist for other things. Maybe you can go for a robust warranty?

[Larry735dn1]

OK so the feedback from the Porsche service centre is that cyl no 3 is scored...very bad news. Their suggestion is new engine needed, whether a short or half engine... The price rel to car residual value means this is not a sensible option, unless I can get some contribution from Porsche.. So I need all the ammo I can get. Does anyone know of successful goodwill applications to Porsche (US, UK, EUR) in similar cases (6-7 year old car, 65k miles, owned from new etc..)?

Also wonder what may have caused the scoring to occur; whilst it can be a tolerance issue it should not just show up all of a sudden... suppose something might have caused the piston ring damage and things have gotten worse from there.. any suggestions?

Any other advice ? I suppose if we leave it as is we will risk that the engine locks up at some point far from home...

[SA321]

bad engineering is one reason for scored walls. the number of cayennes with this problem is large enogh to start a class action except in Europe that doesnt exist and in the US you have 4 year warranty so nobody complains. i realize it is not going to help you

[mazhukas]

Hello. for Porsche Cayenne S

piston slap, ticking noise, engine replacement

have the same problem in Switzerland, Cayenne S 2004 (today 120'000 km) - about 2 years ago (beg 2009) at 80'000 km, the "ticking noise" started...

went to the dealership - their solution: "CHANGE THE ENGINE".

went to some other Cayenne servicing garages - the explanation is: "bad/defective alloy (mix of steel-aluminium-other metals) at production causing defective pistons/cylinders".

Wrote a letter to Porsche Switzerland - their answer: "goodwill lies with your dealership".

wrote to dealership asking about "goodwill": no news...

have been driving with the "ticking" for 2 years now... apart from the annoying noise - the car is perfect!

am not sure what to do next, but it seems that more and more of these cases are coming up...

i shall write again - will keep you posted

ALSO, it happened to a friend of mine in Geneva 2 years ago (he just changed the car)....

Edited May 4, 2011 by mazhukas

[ActiveLife]

I have recently read quite a few posts about this engine issue, which has me nervous as I just bought an 05 Cayenne S that I am picking up from the dealer tomorrow.

Just a thought... if this problem does show up in a couple of years, and I don't want to pay for a short block... is it possible to just rebuild the motor instead of replacing it? Bore or re-sleeve the cylinders and put new rings and/or pistons in? Please correct me if this isn't feasible, I am mechanically inclined enough to do the work, its the insane (out of warranty) dealer costs that I'm reading about that is practically half the cost of the initial purchase... I'm just looking for a more financially reasonable way of fixing the issue should it occur.

Your thoughts?

:help:

-Cameron

Edited May 6, 2011 by ActiveLife

[Larry735dn1]

Hi, A lot of Cayennes must have been running without major issues... However there are some really poor solutions that should not occur in a car of this perceived quality. One is the dreaded Coolant pipes.. The coolant pipes in the "V" of the engine are made of plastic, goes brittle and are prone to crack with a sudden drop of coolant. It is a $ 1500-1800 job to replace with the aluminium replacement kit, although possible to DIY.. The other is this cylinder scoring issue - the AluSil alloy is evidently not a good enough material, and/or the coating on cylinder walls and pistons are not up to the job. Porsche typically advise new engine when the scoring occur.. They seem to want to wash their hands of these clear manufacturing faults (in materials choice), which is really poor. The coolant pipes alone should have had a recall.. The 911 (997 and 996) are apparently even worse, with lots of engines blowing)... There may be other issues I have not encountered yet.. No wonder they are a very profitable company with all the engine replacements needed at extortionate prices..

[ActiveLife]

Larry,

Agreed, these problems should be addressed by Porsche. My recent used Cayenne purchase has included the aluminum plumbing kit, which I will be installing myself in about a week. The engine alloy issues however should have never passed Porsche standards and pre-production testing nor should the 996 and 997's problems. Seriously, this is PORSCHE... since when did they start selling junk cars?

I have found a source for a new "short block" Cayenne 4.5L engine here in the US for roughly $5,000usd. Although expensive for a short block... I believe that this price is reasonable enough that if this issue should occur with my recent Cayenne purchase, I would just replace the engine myself as the dealer charges far too much.

Larry,

Have you had your engine replaced yet?

[Larry735dn1]

Have not gone ahead with engine replacement yet. So far I have been quoted prices that make the new engine route non-viable...Complete engine @ $ 21,700 and Short engine (more labour) @ $ 17,600 equivalent... Incl VAT (sales tax) but still extortionate relative to residual value of the car... Am pursuing Porsche for contribution and will take that all the way, as both these problems are unacceptable to push over on the client when all maintenance, oil changes etc have been meticulously adhered to. Only 65,000 miles after all... If all else fails I think replacement engine may be the way to go, or sell the car to somebody who wants the DIY project.. If Prosche does not sit up and contribute, this will be my last Porsche. And many Porsche owning friends will be put off too..

BTW, your short block source....is that a proper new short engine? I was quoted $9,700 equivalent for the short block from Porsche here... might make sense to ship it over.. that's rip-off UK dealers for you anyway..

Edited May 7, 2011 by Larry735dn1

[Davidsj]

Hi Larry,

I have just read your post, sorry to hear but I am in the same boat

I own cayenne 2004 s v8, purchased from opc, fully serviced by opc so it would have no problems, however never had the warranty.

It began shuddering, mis firing, I took it to opc they did a compression test and confirmed that cylinder 7 was showing no compression. TO continue investigating they need to strip the engine down and see if piston, bore, scoring or valve damage. They have said that it is possible it may need new engine, like you hav pointed out, the cars value and new engine value are not far apart, so what do you do?

Have you found the underlying problem with yours, did porsche offer any goodwill?

Have followed the forum occasionally and now have a question re a current problem ..

My wife's Porsche Cayenne S - 2004 with 65k miles - owned from new - has developed an engine noise which initially sounded like valve ticking, but is now a more distinct engine knock. The symptom is a distinct ticking or knocking noise on every second rev (car idles very low at some 580 rpm at moment, giving some 290 knocks/minute. The knocking disappears at higher revs (> 1,500-2,000) but does not go away entirely when engine warms up. The knock appear to come from the right hand top area, but couldn't rule out "piston slap". Other than this the car runs smooth with full power and no misfire, no smoke, oil and coolant fine. Last year we had to replace the silly coolant pipes in the V of the engine after the plastic ones cracked with loss of coolant, and Porsche also did a full service at the time. Car came back from service very low in oil (about min on dipstick) and with a faulty oil pressure / temp sensor, which we discovered a little later.

Wife took the car to Porsche outside London, where they did some simple diagnostic (without the use of endoscope or camera) and declared that one of the cylinders was scored and that a new engine was the prescription - hand over £14k plus VAT please.. Not fun at all, and the diagnosis seem questionable...how can you verify scoring in the cylinder by peering through a small spark plug hole without an endoscope...

Took it to another dealer for a listen-to, and the technician there thought it was likely top related (Cam, valve bucket..), whereas the service manager suggested piston slap. Car going back tomorrow for some more diagnostic, perhaps the cam cover has to come off... So the meter is running..

I wonder if in your aggregate wisdom you would have some advice for me. I've heard everything from Cam / valve buckets through water pump to piston slap, but given the symptoms is one or the other more likely? I certainly intend to pursue the issue with Porsche UK to try to get some goodwill contribution (not easy when car is 7 years old and out of warranty. The car had major cooling pipe replacement and associated engine oil sensor issues less than a year and 5k miles ago at the main dealer (Porsche in their wisdom used plastic coolant pipes in the V of the V8, and these pipes are prone to cracking which happened - as described in detail elsewhere on the forum.

If worst case is confirmed, where can one source a good engine, given that a new engine is gong to be uneconomical relative to the cars residual value...

Thanks for your pointers..

[Davidsj]

Hi Larry,

I have just read your post, sorry to hear but I am in the same boat

I own cayenne 2004 s v8, purchased from opc, fully serviced by opc so it would have no problems, however never had the warranty.

It began shuddering, mis firing, I took it to opc they did a compression test and confirmed that cylinder 7 was showing no compression. TO continue investigating they need to strip the engine down and see if piston, bore, scoring or valve damage. They have said that it is possible it may need new engine, like you hav pointed out, the cars value and new engine value are not far apart, so what do you do?

Have you found the underlying problem with yours, did porsche offer any goodwill?

[Larry735dn1]

Hi, sorry to hear that... clearly there are some weaknesses with these engines. Several friends have had to get new engines for their 997s and 996s too, Porsche should sit up and address the issue it clearly has with engine weakness.. I have approached Porsche Uk for goodwill. I am also going after the dealer who returned the car with faults after changing the coolant pipes and doing a major service. They returned the car without filling enough oil, with a faulty oil pressure monitor, and with air locks in the coolant system....which is likely how the damage occurred in the first place. Have not had a reply yet, but will escalate soon to make them understand I'm serious..

BTW our car still runs nicely, except for the knocking on low revs (which will only get worse of course). No misfire, and no noticeable loss of power... The dealers have not done compression tests however, which they should have done..

Will try to post back as case develops.

Good luck..

[ActiveLife]

Have not gone ahead with engine replacement yet. So far I have been quoted prices that make the new engine route non-viable...Complete engine @ $ 21,700 and Short engine (more labour) @ $ 17,600 equivalent... Incl VAT (sales tax) but still extortionate relative to residual value of the car... Am pursuing Porsche for contribution and will take that all the way, as both these problems are unacceptable to push over on the client when all maintenance, oil changes etc have been meticulously adhered to. Only 65,000 miles after all... If all else fails I think replacement engine may be the way to go, or sell the car to somebody who wants the DIY project.. If Prosche does not sit up and contribute, this will be my last Porsche. And many Porsche owning friends will be put off too..

BTW, your short block source....is that a proper new short engine? I was quoted $9,700 equivalent for the short block from Porsche here... might make sense to ship it over.. that's rip-off UK dealers for you anyway..

Larry,

I have confirmed the price of the short block from a Porsche dealer here in the USA @ $5,000usd. Plus sales tax and shipping of course. I'm not sure of the expenses of shipping a short block over the pond, but never the less, if it will save you a few thousand, it may just be worth it.

All my best,

-Cameron

[bigbuzuki]

These guys in the USA have the short block for USD $4555. They do ship internationally. Edited May 30, 2011 by bigbuzuki

[Larry735dn1]

Thanks for these pointers guys - could come in handy... Still hope Porsche UK will do the right thing and will pursue the dealer who may have caused the damage as far as it will go..

BTW One scored cylinder (only cyl 3) must be caused by something (like snapped piston ring perhaps?)... Strangely enough the dealer didn't do a compression test, but how likely is it that a new piston or piston rings may solve the problem, at least temporarily - it obviously does not remove the scoring, and how big a job is it to get the piston out anyway? Do you need "engine out" to change piston rings? Anyone know / done this?

Edited May 30, 2011 by Larry735dn1

[Sam_You_L]

Hello Larry,

I have the same issues. I purchased a 2004 Porsche Cayenne S literally two days ago, and have engine knocking sound. The dealer that sold me the car said it would fix for maybe $2,000 US, but I took it to a certified Porsche dealership and based on the sound alone they said there is internal motor damage and I need a new engine. Not sure if that is the case, well hoping it isn't. It appears that there have been plenty of issues with the Cayenne. I love the car, it is truly amazing, just that darn knocking noise and the fear of the vehicle not working, or worse dying on me when I drive.

I am trying to the return the vehicle since it has only been two days since my purchase, I shall see how if it works.

Below is a video of my Cayenne. Is that what your wife's Cayenne sounds like? If anyone has any suggestions regarding the noise, or how to possibly return the vehicle please let me know.

Thanks so much,

Sam

[Larry735dn1]

Hi Sam,

Sorry to hear that. Yes the heavier knocking sounds like what they call piston slap. In my case a bore scope inspection showed scoring in cyl no 3. Scoring shouldn't in itself cause knocking, so more likely there is a tolerance issue or perhaps broken piston or piston ring causing both the knocking and the scoring... From what I can ascertain, Porsche prescribe a new engine block due to all the labour involved in repairing the bore, but it is less clear why one could not replace the offending piston/rings and live with a little scoring..?

Porsche seem to wash their hands of the problem (I have asked for goodwill contribution), although clearly there is a weakness in materials and /or design. We have owned the car since new, and it hads been meticulously maintained throughout by official Porsche dealers. And after last service some 4k miles ago the car came back with very low oil level, a faulty oil monitor and air licks in the coolant system... yet they say it is notthing to do with them !! I'm going to sue them... Just like with the coolant pipes which are designed with unsuitable materials. It is unacceptable that a top end marque should get away with this, and I for one will never buy a Porsche again. I shall go out of my way to discourage friends to buy one too.

As for your purchase, I do not know on what basis you bought the car. If it was "as is" you may have a weak legal standing. But if it was from a reputable dealer it would be surprising if you did not have a case, unless you received a discount allowing for the problem.

Wish you Good luck.

[mazhukas]

Hello

have the same KNOCKING problem with my Porsche. In Switzerland.

The Porsche center does not want to do anything about it.

I am thinking of driving to Germany to try to fix it.

It is scandalous that they are refusing to even discuss the matter.

Have you had any progress??

[Yidgaling]

Hi All,

Just got my Cayenne S back form an engine overhaul, scored piston liners at 60,000 miles.

I used a company in Yorkshire called ProPorsche.

Now £8K lighter with a new short motor fitted.

I understand that these are a common fault with the 4.5 V8 engine.

The rumour is that the piston lining in the casting was not up to the job ??

does anyone have any more information or similar problems with their car.

Andy