Turbo / MAF replacement, Oil found

[Zakowsky]

So just to rattle on a bit here, first of all thanks ekstroemtj and lewisweller for taking the time to answer questions like this. Ekstroemtj, you commented a few posts back on how not many people are stepping up to do so, but you guys certainly are, and I think all the photos and info that is shared will help many people for years to come – already almost 2000 views on this thread alone. The irony here is with the Cayenne, Porsche tried to make a vehicle targeted at customers that would just take it into the dealer to service, which is somewhat in contrast to many of the other Porsches that have many more resources for enthusiasts to work on their own vehicles. The irony is that the Cayenne is developing a large set of online resources such as this and DIY guides to make up for it. And that is great, so thanks again guys.

 

As for the venturi tube itself, wow, great catch Lewis! I never would have guessed this, as this is how I bought it. For my second comment, I bought this Cayenne from someone who had it extensively serviced at the dealer, or at a very expensive private tuning shop. Going over the bills they spent 22 thousand dollars over the past 3 years. But when I look at the quality of the work that has been done, I am really appalled. For example, when I replaced the hatch shocks, those white pieces of plastic were broken; clips were bent in the headliner and not attached properly, just a lack of careful workmanship. So it doesn’t surprise me this is on the wrong side. But again, I never would have guessed, so thanks, and I’m going to go work on it now!

[Zakowsky]

OK, one quick paranoid question - it's ready to take off, but to get the pin out to remove the Y tube you have to disconnect the electrical connection to the throttle body. If the engine is off and the key is out, will I have to have reset any codes after doing this? There seems to be something wrong with my OBD2 connector...and I guess in general, can you disconnect electrical components on the engine when it is off without tripping a code? Or are there systems that are continuously monitored? Thanks!

[Zakowsky]

Reflecting on my workmanship comment, he we go again – on one side and in the Y pipe there are metal rings to take the force of the ring clamp, but on the passenger side it was missing! Consequently the pipe is crushed in a bit, and maybe not sealing like it should. This is why I work on my own vehicles!

 

[ekstroemtj]

Good Morning,

the hose coming from intercooler going into y pipe should be fitted with 2! clamps each side. How is your y pipe looking inside? Oil? Dry! 

[ekstroemtj]

4 hours ago, Zakowsky said:

OK, one quick paranoid question - it's ready to take off, but to get the pin out to remove the Y tube you have to disconnect the electrical connection to the throttle body. If the engine is off and the key is out, will I have to have reset any codes after doing this? There seems to be something wrong with my OBD2 connector...and I guess in general, can you disconnect electrical components on the engine when it is off without tripping a code? Or are there systems that are continuously monitored? Thanks!

 

 

After you put everything together again its necessary to make a throttle adaption.  Very easy. 

 

Switch on ignition WITHOUT Start

dont touch any pedal.

wait for one minute. You will hear the adaption process in the engine bay. Some klick klack possible to hear. 

after switch OFF

start the engine like usual

[ekstroemtj]

E

Edited November 20, 2016 by ekstroemtj
Double post

[ekstroemtj]

Here is onother question.  

I replaced today the pressure line (9+10 on the diagramm) which is going from n75 valve to the turbo. Dont know what it does?! I blow into the pipe and i hear the air coming out on the air duct which is connected to the air filter box. Is this right?

[ekstroemtj]

9 hours ago, Zakowsky said:

OK, one quick paranoid question - it's ready to take off, but to get the pin out to remove the Y tube you have to disconnect the electrical connection to the throttle body. If the engine is off and the key is out, will I have to have reset any codes after doing this? There seems to be something wrong with my OBD2 connector...and I guess in general, can you disconnect electrical components on the engine when it is off without tripping a code? Or are there systems that are continuously monitored? Thanks!

 

 

in some way i believe you are fighting with a air leak somewhere. Like me. 

If you ruled out MAF, coiles and plugs the only way is to check all this places:

 

http://www.pelicanparts.com/techarticles/Porsche-Cayenne/69-FUEL-Fixing_Common_Vacuum_Leaks/69-FUEL-Fixing_Common_Vacuum_Leaks.htm

[Zakowsky]

So I pulled everything apart and reassembled, here's how it went.

 

18 hours ago, ekstroemtj said:

Good Morning,

the hose coming from intercooler going into y pipe should be fitted with 2! clamps each side. How is your y pipe looking inside? Oil? Dry! 

 

The hose (it does have the 2 clamps) on the drivers side and Y pipe were a bit oily, but a lot better than before I drained the oil from the intercooler hose on the bottom. What did surprise me is that my Y pipe is starting to de-laminate inside. You can see the plastic cracking and coming loose at the arrow:

 

I also seem to have a really big off set on the drivers side for some reason:

 

18 hours ago, ekstroemtj said:

 

 

After you put everything together again its necessary to make a throttle adaption.  Very easy. 

 

Switch on ignition WITHOUT Start

dont touch any pedal.

wait for one minute. You will hear the adaption process in the engine bay. Some klick klack possible to hear. 

after switch OFF

start the engine like usual

 

I did the throttle adaptation and I was freaked out at first because the first time I drove it it wouldn't shift out of 2nd after accelerating(!) but after a few minutes of driving it was fine.

 

15 hours ago, ekstroemtj said:

Here is onother question.  

I replaced today the pressure line (9+10 on the diagramm) which is going from n75 valve to the turbo. Dont know what it does?! I blow into the pipe and i hear the air coming out on the air duct which is connected to the air filter box. Is this right?

 

I should have tested this when I had it all apart - I will probably take it apart again this week and will try blowing in it then.

 

After taking out the Y pipe I noticed one of the clips on the venturi line is broken, which might contribute to it not attaching well. I moved it in front of the other hoses as Lewis suggested and it did fit better, although still not perfectly. I will have to look at where it is attached at the back next.

 

After driving it all day, no more oil was seen around this fitting. As far as performance goes, I think I am indeed still looking for an air leak somewhere. Before I had a rough idle 50% of the time at lights, depending on if I had been driving it hard or not (hard driving = smooth idle). Now I still get this occasionally, but when it is smooth it is almost perfect, and the roughness is less. The two main issues left are a lack of power, sometimes...if I manually shift with PSM off it can go OK, with the boost pressure going to 8.0 then dropping to 0.7 as the revs get higher, as long as I shift by 6500. But in automatic the boost will fall as low as 0.5 in 3rd and 4th gear, PSM on or off. Even when shifting manually, 3rd doesn't pull as hard as I think it used to after 4500. And there is still is this sound after the wastegates open that doesn't seem right; not very loud but it is like a wheezing sound that again wasn't there when I got it. The other problem is when slowing to a stop it drops to 400 rpm and then recovers, and that is actually worse after all this. I did notice a very slight leak around one of the injectors; need to look at that as well.

 

Anyway overall it is better, but I am still looking for leaks as well. I was thinking a smoke test should be next. I thought I would go green after looking at all the fire-based DIY smoke testers on YouTube. But I figured the pressure was a bit low and maybe all that water vapor woldn't be good for things...but good for a laugh anyway!

 

 

[lewisweller]

21 hours ago, ekstroemtj said:

Here is onother question.  

I replaced today the pressure line (9+10 on the diagramm) which is going from n75 valve to the turbo. Dont know what it does?! I blow into the pipe and i hear the air coming out on the air duct which is connected to the air filter box. Is this right?

Hi Thomas, one night of working on a site and I missed so many posts! Lol

 

Ok this pipe is the boost reference from the passenger side turbo. The n75 valve uses this boost pressure to control the wastegates opening. If this pipe leaks usual you get Overboost code. I changed this pipe the other day and posted the pictures. As below pics it the lower pipe with the securing clip attached to the alternator.

You have to take the turbo pipes off to access this pipe and replace.  

[ekstroemtj]

lewis... the pipe is not leaking. 

Just when i blow into this pipe, air is coming out at the air hose which is connected to air filter box.  Is this usual?

[lewisweller]

10 minutes ago, ekstroemtj said:

lewis... the pipe is not leaking. 

Just when i blow into this pipe, air is coming out at the air hose which is connected to air filter box.  Is this usual?

Normal yes pipe is straight through. No check valve or anything so you can hear the air travelling into the turbo and back around up to th airbox. 

[ekstroemtj]

Great. Thanks a lot

[ekstroemtj]

Some time ago the picture from the area close to the driver side turbo charger was posted. See below the pic with the arrow. 

Is this the hose 14/ 15 ? If yes, is a replacement possible without taking away a lot of stuff? 

I need to replace mine. 

[lewisweller]

1 hour ago, ekstroemtj said:

Some time ago the picture from the area close to the driver side turbo charger was posted. See below the pic with the arrow. 

Is this the hose 14/ 15 ? If yes, is a replacement possible without taking away a lot of stuff? 

I need to replace mine. 

It's pipe 15 thomas. 

To get access you will need to remove airbox cover and the turbo intake pipe/MAF sensor then you can just about reach inside to get your fingers on the pipe 15 clamp to squeeze the tabs and release the pipe off. Then separate from pipe 14 and wiggle out from between the Serpentine belt. 

If you are going to replaced 15 I would also replace 14 as well it only makes sense. You will need to remove the Y pipe to access the small pipe and non return valve underneath the Y pipe. 

I tested mine when I stripped it out the other day to change the orings. My pipe 14 and 15 was new when head gasket work was done.

 

 

 

Edited November 21, 2016 by lewisweller

[ekstroemtj]

mine looks terrible. Somebody before try to repair something here. Maybe this could be part of my problem.

[lewisweller]

Update..........after new filter and regulator. (don't think it was the smoking gun here but as a service item it could only do harm to my wallet!) it does feel better and cleaner at higher rpm now which could have been fuel related I can't really say definitely. It's holding a higher rpm shift too which is puzzling. ?

 

Fixed pipe 5 leak (diy job, hydraulic hose and two jubilee clips) and had some time to clear codes and put on a few hundred km's. Massive difference now, throttle response is great, low end grunt when changing Lanes and needing a bit extra quick speed very good now, won't downshift all the time looking for power it just goes and pulls like a train. Full Throttle higher rpm is amazing this engine sings to 7,000rpm. Reaches speeds to lose my licence in a flash. 

 

Last night I work on a site the whole night and the car pretty much was running and idling between shifting locations short runs doing checking with my team of irrigation guys. Ran great idle is perfect, cooling system good even with AC off the temp held well creeping just above 80oC until fan kicks in and thermostat fully opens at 87oC I believe. 

The drive home at 5am was a blast open roads and no cars had the thing going like a stabbed rat. 

So what's left.........the "stutter" even though less pronounce than ever before it is still there. 

I just went to a meeting earlier and had a complete cold start, there is no stutter whilst it's on warm up, as soon as the temp gets near 80oC the stutter appeared. This is lean misfire under load for sure. But what exactly is making it lean I don't know. 

If you drive low acceleration, cruise or go down hill obviously load is less and the stutter is pretty much none existent. Uphill or asking for heavy acceleration from lower rpm the stutter is repeatable every time once warm. 

As the boost comes in and the rpm's start to build with a high load demand it stutters until the engine catches up with the load demand then it flies without stuttering. 

 

Don't get me wrong the car is soooooo much better to drive now. I'm so close to making it perfect and as an Engineer and Virgo perfectionist I need it to be perfect. 

[lewisweller]

6 minutes ago, ekstroemtj said:

mine looks terrible. Somebody before try to repair something here. Maybe this could be part of my problem.

I bet that leaks! 

Buy 15 and 14 fit new and forget that as a possible problem so you can move on. 

Edited November 21, 2016 by lewisweller

[lewisweller]

Ran diagnostic last night looking at the pre and post cat o2 sensors. The postcat sensor reading is in volts and the pre cat "wideband" air/fuel lambda sensor reads in milli amps (current). 

 

What I found is the bank 1 sensor 1 lambda sensor is not producing enough current milli amps, take a look at the first picture of 4 times I repeated snap throttle opening and the bank 2 sensor 1 yellow line hit max milli-amps where as the blue line bank 1 sensor 1 doesn't get half way to rich milli-amps. So this could be the issue with the stutter hesitation lazy wide band sensor! As my fuel trims are good and the idle is steady and lambda 1 ie 14.7:1 I dont think it's any other possibility like maf (new) ignition (all new) or fuel (new filter and regulator). No exhaust leaks. 

During cold start and warm up the engine drives very well, once warm it stutters all the time. 

Anyone disagree or have more experience on this?? 

 

Second picture is the bank 1+2 sensor 2 post cat 02 sensors in volts.  

You can see the red line which is bank 2 sensor 2 is normal stable line as the cat does its job whereas bank 1 sensor 2 green line is fluctuating either as a direct result of the wide band sensor 1 lambda fault and/or the cat efficiency is poor. 

As the post cat 02 sensors have no effect on air/fuel mixture I don't intend to address this yet. 

I am ruling out also a clogged cat because that would highlight performance at higher rpm, the engine would feel suffocated whereas at high rpm the engine runs very well. 

 

Mark Mbagge you changed the bank 1+2 sensor 1 what tools did you use and any advice which way to get in there pls? 

How did you diagnose the o2 sensor fault and what symptoms was you experiencing. 

Edited November 25, 2016 by lewisweller
incorrect information and statements after further technical research

[lewisweller]

On 21 November 2016 at 10:10 AM, Zakowsky said:

So I pulled everything apart and reassembled, here's how it went.

 

 

The hose (it does have the 2 clamps) on the drivers side and Y pipe were a bit oily, but a lot better than before I drained the oil from the intercooler hose on the bottom. What did surprise me is that my Y pipe is starting to de-laminate inside. You can see the plastic cracking and coming loose at the arrow:

 

I also seem to have a really big off set on the drivers side for some reason:

 

 

I did the throttle adaptation and I was freaked out at first because the first time I drove it it wouldn't shift out of 2nd after accelerating(!) but after a few minutes of driving it was fine.

 

 

I should have tested this when I had it all apart - I will probably take it apart again this week and will try blowing in it then.

 

After taking out the Y pipe I noticed one of the clips on the venturi line is broken, which might contribute to it not attaching well. I moved it in front of the other hoses as Lewis suggested and it did fit better, although still not perfectly. I will have to look at where it is attached at the back next.

 

After driving it all day, no more oil was seen around this fitting. As far as performance goes, I think I am indeed still looking for an air leak somewhere. Before I had a rough idle 50% of the time at lights, depending on if I had been driving it hard or not (hard driving = smooth idle). Now I still get this occasionally, but when it is smooth it is almost perfect, and the roughness is less. The two main issues left are a lack of power, sometimes...if I manually shift with PSM off it can go OK, with the boost pressure going to 8.0 then dropping to 0.7 as the revs get higher, as long as I shift by 6500. But in automatic the boost will fall as low as 0.5 in 3rd and 4th gear, PSM on or off. Even when shifting manually, 3rd doesn't pull as hard as I think it used to after 4500. And there is still is this sound after the wastegates open that doesn't seem right; not very loud but it is like a wheezing sound that again wasn't there when I got it. The other problem is when slowing to a stop it drops to 400 rpm and then recovers, and that is actually worse after all this. I did notice a very slight leak around one of the injectors; need to look at that as well.

 

Anyway overall it is better, but I am still looking for leaks as well. I was thinking a smoke test should be next. I thought I would go green after looking at all the fire-based DIY smoke testers on YouTube. But I figured the pressure was a bit low and maybe all that water vapor woldn't be good for things...but good for a laugh anyway!

 

 

Did you check the black colour check valves,? First picture.

They have an arrow which shows the open direction, blow and suck hard to confirm they work. 

Also check the 3 way check valve 2nd picture below. Blow into pipe where arrowed number 13 is pointing, the air will go through to either other port as normal operation, you need to cover one port to get the other to open as your breath isn't enough to open both simultaneously against the diaphragms. Then blow back though the other two port and you should not be able to blow any air at all through either. 

 

There are some more check valves white and black/ grey at the back of the manifold which also can be checked for functions and the vac pipes too. 

 

I've learnt with a vacuum leak at the manifold intake side the idle can mantain with the throttle body whining away trying to compensate for the extra air, when accelerating the throttle response is rubbish and hesitant, boost takes longer to build as the air escapes. 

If you have a divertor valve problem ie split diaphragm or vac pipe running to it is split/leaking the car is very jerky and will under boost as well +-0.5 bar only, lift off surging of boost which is not released from the turbo is felt as the jerkyness. 

 

Leak around the injector would would my first thing to fix, leaking fuel or leaking air in either way can't be healthy. Pictures pls......

 

[Zakowsky]

Thanks Lewis – my job for this weekend will be the check valves and to go over the vacuum lines, especially at the back where I haven’t really looked much yet. The boost is fine sometimes (0.8 – 0.7) but other times not, and there still is what I think is a minor surging sound when I lift off, after the wastgates open. I recorded it with the GoPro, just have to get it processed and posted.

 

Pictures always! Here is the leak from the rear injector, the others are fine.

 

I suppose I haven’t paid much attention to this because on my old Jeeps most of the injectors leak and they still run fine! - but then again, this isn’t a Jeep engine.  I have also had engines where as soon as you pull the fuel rails off, all the o-rings start leaking, so I guess I try to avoid doing so. I am not sure how long this has been like this – I need to clean it off and see how it builds over time. But maybe this does contribute to the variable rough idle and maybe even the hard starting.

 

[lewisweller]

On 24 November 2016 at 9:22 AM, Zakowsky said:

Thanks Lewis – my job for this weekend will be the check valves and to go over the vacuum lines, especially at the back where I haven’t really looked much yet. The boost is fine sometimes (0.8 – 0.7) but other times not, and there still is what I think is a minor surging sound when I lift off, after the wastgates open. I recorded it with the GoPro, just have to get it processed and posted.

 

Pictures always! Here is the leak from the rear injector, the others are fine.

 

I suppose I haven’t paid much attention to this because on my old Jeeps most of the injectors leak and they still run fine! - but then again, this isn’t a Jeep engine.  I have also had engines where as soon as you pull the fuel rails off, all the o-rings start leaking, so I guess I try to avoid doing so. I am not sure how long this has been like this – I need to clean it off and see how it builds over time. But maybe this does contribute to the variable rough idle and maybe even the hard starting.

 

The injector orings are cheap, my advice would be to remove the intake manifold this gives you the opportunity to do the following:

Change all injector orings

Replace intake manifold rubber gaskets

Replace throttle body gasket and clean 

Check all the pipes at the back and check valves and change over valve piping (this controls the divertor valve opening and closing. 

Also a great time to check all the cooling pipes and wires to start motor are all good clean tight not leaking etc. 

Even take out the starter disassemble and clean up all insides and connectors if you got a spare hour. 

Manifold only takes 45 mins to remove and 30 mins to reinstall. 

 

Disconnect battery of course. 

Before you disconnect the fuel line either leave over night to make sure it Depressurised mostly or pull the fuel pump fuses whilst running and let the engine die relieving all the pressure. 

Lots of pictures in my earlier post here 

 

Edited November 25, 2016 by lewisweller

[Zakowsky]

There are some great pictures there - I think I will go ahead and take off the manifold; the coolant pipes were upgraded but I occasionally smell what might be coolant, so I should check them out. I am going to order in the o-rings (top and bottom I assume), intake and throttle body gaskets first, and if the battery and throttle body are going to come off, I really need to get the OBD online first as well. While I wait for those I am going to go over all the check valves I can get to this weekend.

[ekstroemtj]

i changed almost every pipe which is possible. 

The connection system under the y pipe i also replaced with new tubes.  Same on the firewall. I changed the CVS membrane which i ordered from russia.  So what, same hesitation as soon as i hit the throttle a bit more. 

[ekstroemtj]

Membrane