metallic noise - tap tap tap - CTT05 - bad lifter?

[gunzie]

I'm having this metallic noise at idle ( tap tap tap) in my 05 CTT (90.000km or about 60.000 miles); when the engine is cold it's allmost unhearable, but when it's at operating temperature it is very distinctively there. (suspecting thick (cold) vs thin (warm) oil is having an effect; that's why I immediately started suspecting a bad hydraulic lifter)

When making more rpm's, frequency of tap tap tap increases also, and around 2000 rpms it either disappears or is drowned out by overall engine noise.

when decelerating rpm's, and the idle pick's up again, it seems to be gone for an instant but then is there again. I can hear the noise also during decelaration.

I've used a stethoscope and according to me the sound is the clearest around the valves on the driver's seat bank, first cylinder from the front. Then again I'm not sure if it might not be the variocam system on that side.

I should admit a number of weeks ago I first starting hearing the noise a couple of days after full load conditions (about 240km/h and accelarating when certainly the engine icon started flashing). In my memory I somehow link the two together.

I've tried teflon additives on recommendation from my Porsche dealer, and also a lifter clearing additive, but all to no avail.

Seems like the only solution, according to my Porsche dealer, is to take the engine out of the car (because you cannot dismantle valves/lifters/camwheels with the engine mounted)

and that will take about a week...his rough estimate was about 5000 euros (that's about 9000$ I guess)

My dealer claims he has been asking around with other dealers and the importer and I seem to be the first one with this problem. No fault codes were found.

Oh, and did I mention my Porsche 2nd hand warranty just expired the month before? Just my luck!

Can I have your opinions please? Are there more diagnostic tests which can be done prior to dismantling? Is it true the engine has to be out of the car to be able to replace/inspect the hydraulic lifters? Does 1 week sound right to you for that? (my dealer argued it is a turbo..)

Any other known common sources of this kind of noise? (I've been reading about a pulley producing a more plastic clack clack noise, but this is clearly a metallic noise...)

Should dismantling of the engine be the only option, would you recommend to change anything else? (thinking about bearings, piston rings, etc)

Your feedback is greatly appreciated!

Cheers, Gunther

[RFM]

It works a lot easier with the engine out of the car, they need the car for 1 week but they works not continually on it i assume. Let check the noisy cylinder liner inside/piston with a devise before dismantling the cylinder head, there are Turbo's with cylinder liner damage well known and it is the same noise as a faulty lifter. Hope the best for you.

[gunzie]

Thanks RFM!

They will indeed check each cilinder with a microscope via the spark plug hole prior to taking the engine out.

If liner damage is the case then I guess I would better go for new cilynders + pistons etc (complete revision), no?

The car is going in on August,18 for 2 weeks straight. I want inform myself on beforehand off course.

Thanks for your swift reply!

Cheers, Gunther.

It works a lot easier with the engine out of the car, they need the car for 1 week but they works not continually on it i assume. Let check the noisy cylinder liner inside/piston with a devise before dismantling the cylinder head, there are Turbo's with cylinder liner damage well known and it is the same noise as a faulty lifter. Hope the best for you.

[RFM]

Cylinder liners are not available separately, it means a new cylinder block. Wait for the dealer's advise and rapport back later on what the real trouble and the solution is.

[porha]

Hello,

this is something like our Cayenne S,read topic Knocking during the cold start.

Our knocking: When making more rpm's, frequency of tap tap tap increases also, and around 2000 rpms it either disappears or is drowned out by overall engine noise.

when decelerating rpm's, and the idle pick's up again, it seems to be gone for an instant but then is there again. I can hear the noise also during decelaration:

Like yours,but not the same engine

Edited August 4, 2008 by porha

[SeattleBum]

I had a similar metallic clicking sound in my CTS-V. I had it modified with a supercharger, headers, exhaust and a bunch more. I took it into the shop and they diagnosed a bad bearing in the supercharger. They had it rebuilt and reinstalled it only to find the clicking noise still there. It ended up being a $20 header gasket that fixed the problem. Apparently the stainless steel headers make metallic pinging sounds when exhaust gasses are escaping through the gaskets. I'm just trying to say that you should look for the simple fixes b/f you start tearing your engine apart.

[gunzie]

I had a similar metallic clicking sound in my CTS-V. I had it modified with a supercharger, headers, exhaust and a bunch more. I took it into the shop and they diagnosed a bad bearing in the supercharger. They had it rebuilt and reinstalled it only to find the clicking noise still there. It ended up being a $20 header gasket that fixed the problem. Apparently the stainless steel headers make metallic pinging sounds when exhaust gasses are escaping through the gaskets. I'm just trying to say that you should look for the simple fixes b/f you start tearing your engine apart.

I've made a small video; should have done that in the first place instead of trying to describe the noise..

anyone else recognize this?

[Loren]

I had a similar metallic clicking sound in my CTS-V. I had it modified with a supercharger, headers, exhaust and a bunch more. I took it into the shop and they diagnosed a bad bearing in the supercharger. They had it rebuilt and reinstalled it only to find the clicking noise still there. It ended up being a $20 header gasket that fixed the problem. Apparently the stainless steel headers make metallic pinging sounds when exhaust gasses are escaping through the gaskets. I'm just trying to say that you should look for the simple fixes b/f you start tearing your engine apart.

I've made a small video; should have done that in the first place instead of trying to describe the noise..

anyone else recognize this?

Please keep this on one thread or the other - not both places. (Don't double post)

That just wastes time and resources.

Thanks.

[SeattleBum]

I had a similar metallic clicking sound in my CTS-V. I had it modified with a supercharger, headers, exhaust and a bunch more. I took it into the shop and they diagnosed a bad bearing in the supercharger. They had it rebuilt and reinstalled it only to find the clicking noise still there. It ended up being a $20 header gasket that fixed the problem. Apparently the stainless steel headers make metallic pinging sounds when exhaust gasses are escaping through the gaskets. I'm just trying to say that you should look for the simple fixes b/f you start tearing your engine apart.

I've made a small video; should have done that in the first place instead of trying to describe the noise..

anyone else recognize this?

Wow, that's quite a knock. Definitely not normal. Sorry I can't help much though. Doesn't sound like the headers.

[gunzie]

OK - the diagnose is set at the Porsche dealer in Belgium - appears my 5th cylinder (that is the frontmost one from the left bank) is worn in and the sound is actually the piston hitting against the cylinder wall due to too much space. On attached picture you can see the damage. So RFM, you were right about cylinder liner damage!

The engine will indeed be revised - new cylinder block etc - the cost is about 12400 € (near 20.000$?) which I'm paying out of my own pocket! :huh:

It feels kind of strange to have the 2nd hand warranty just expired, a 3 year old car with 95.000km now, and then reading this is a common issue with the Cayenne Turbo. RFM, do you have more information about this?

I feel a little bit like I've bought a chinese radio with 6 months warranty; you expect it to be defective after 7 months :angry: ...but this is a Porsche..

Any comments/considerations anyone? I bought the car in Germany, so I will ask for the German porsche center's reactions on this one, before maybe approaching Porsche Germany HQ.

[porha]

Hi,

pretty same like ours,they said that this is some kind of factory mistake,but I still don't know why this happened in our case.A lot of cayenne's died like ours and yours

[porha]

there is a guy in Monchengladbach,I think he could give you some info..

[porha]

too much money,

there are firms in Germany,they rebuild your engine,replace or rebuild your parts,and it's like new.

It's about 6000-7000EUR for complete engine.

You just need to find them.

[gunzie]

OK - the diagnose is set at the Porsche dealer in Belgium - appears my 5th cylinder (that is the frontmost one from the left bank) is worn in and the sound is actually the piston hitting against the cylinder wall due to too much space. On attached picture you can see the damage. So RFM, you were right about cylinder liner damage!

The engine will indeed be revised - new cylinder block etc - the cost is about 12400 € (near 20.000$?) which I'm paying out of my own pocket! :huh:

It feels kind of strange to have the 2nd hand warranty just expired, a 3 year old car with 95.000km now, and then reading this is a common issue with the Cayenne Turbo. RFM, do you have more information about this?

I feel a little bit like I've bought a chinese radio with 6 months warranty; you expect it to be defective after 7 months :angry: ...but this is a Porsche..

Any comments/considerations anyone? I bought the car in Germany, so I will ask for the German porsche center's reactions on this one, before maybe approaching Porsche Germany HQ.

Just got my car back this week - guys from carreramotors did an excellent job, they even kept me updated with regular progress pictures whilst I was on holiday.

Engine was completely rebuild, all wearable parts replaced, and had also the coolant tubes replaced by titanium ones upon recommendation, same for the waterpump.

The job also included wheel alignment, airco refill, test drive, etc..

In the end it cost me some 13K€ with the additional replacements, but I should receive (haven't received it yet) a payback from Porsche Germany for the main parts (pistons & engine block). Better then nothing, although it leaves a sour taste, since no apparent "fault" or reason other then maybe 5th cilinder out of tolerance (manufacturing defect) could be found...the other cilinders were shining like mirrors.

Anyway, I've got an engine now with zero mileage, 1 y warranty on parts again, end well, all's well..:-)

Thank you all for your support & reactions! :-)

Cheers, Gunther.