Zakowsky

So I took my new to me 2004 CTT for my first real longish drive in it today (4 hours), and noticed a new problem. After running on the highway for a while, occasionally on the faster side (140-150 kph), when I would go to slow down I would get jarring downshifts from 5-4, and occasionally from 4-3. Turning the PSM off got rid of it, and it doesn’t happen in normal city driving or cruising at more prescribed speeds like 110 kph. Now, I’ve read all the info about the transmission valve body going bad, but mine was replaced not long ago. Does this suggest anything other than a serious transmission issue, like the tranny fluid should be changed or there is a vacuum leak somewhere? It also seems really determined to learn my driving style when the PSM is on; accelerate hard a few times and the shift points move up for the next few minutes – could this be a training related phenomena? I usually leave the PSM on; goes great with it off but it really kills my mileage! Thanks.

Hope it ran better on your road trip. Mine is right back to where it started before the cleaning. After reading the “Turbo / MAF replacement, Oil found” thread by ekstroemtj, maybe I should jump these posts over to there; sounds like I am going down the same road. I am pretty sure my driver side intercooler is filled with oil and the seal is shot. Project for the next weekend. But I’m not sure how the venturi/crankcase ventilation line connection to the Y pipe (in my photo above) is going to go. It is soaked in oil so probably leaking, but you might even be able to see it, it is at a bit of an angle where it attaches. Probably why it is leaking, and if oil is coming out, I imagine air is getting in. Tracing the line back it also doesn’t seem quite aligned with where it should be, and since it is so inflexible, not sure how I am going to get it seated. But with all that oil in there, I’m sure the MAF sensor just gets dirty again soon after cleaning, leading to the roughness and hard starting.

I fully agree Lewis; and it is indeed in many ways an escape from the stress of real work. Thanks for the leads for the oil problems. A quick check of the AOS and check valve looks OK; but I pulled out my MAP and I was unsettled to see how much oil was in my Y tube. Lots of discussion on this online, and I will diagnose next weekend. Externally on the top of the engine I mainly see oil from this connector, under the Y tube where I suppose it drains into. But the intercoolers will be my next thing to look at.

I didn’t think about heating up the pipes – good idea, thanks. After some more work, the MAFs are finally cleaned and everything is all back together again. Classic 1 hour job that takes 5 hours! But to wrap this up, I thought I would post the results. Before/after observations, although the after has only been for about 40 minutes of driving. 1) Before there were starting problems – up to 5-10 seconds of cranking when cold to get it to start. Tested this twice so far, each time it started instantly! 2) Before there was an unevenness between left and right exhaust. Seems better now. 3) Before the idle would randomly get rough – after it has been smooth at every stop light. 4) Not much change in overall power 5) New behavior when the engine drops down to idle. Before it would go smoothly down to around 550-580 rpm. Now it dives down to 400 rpm, then picks back up to 550. Sounds like I should also clean the throttle body now? Or maybe it needs to adapt again... 6) Right after cleaning, I was freaked out because it was running like crap, backfiring and coughing on the driver’s side. After running it for a while in the morning, that was all gone (big relief!). So as it is maybe one of the last nice days here in Alberta for the year, going to try and get out for a run in the mountains today. Believe it or not I just learned what turning off PSM really does (I thought it was just regulating the suspension). Need to play around that a bit. Thanks again for everyone’s help.

Well, that could have gone better, but I guess it could have gone worse as well. It finally dawned on me to just do the passenger side first to see how these tubes come apart...I traditionally do the easiest side last. The MAF tube rotated as soon as it was unclamped, so there is in fact a problem with the driver’s side. I didn’t take the tube out on the passenger side, as it was easy to unscrew the sensor right there, and the whole side took about 15 minutes to do. For the driver’s side I gave up with the pipe, and used a chain of extensions and U joints on the ratchet to get the MAF out, 1/32 of a turn at a time. Cleaned both, but was a bit worried because in my efforts to get the tube loose, a few drops of WD40 had fallen into the mesh in the MAF tube. Cleaned it up the best I could and fired it up. I will take it out in the morning for a run, but I have that what have I done feeling about this – it was running OK before; still hard to start when cold and would get a bit shaky at idle after driving in traffic. But when I started it, it backfired out the driver’s side like crazy, gurgling and backfiring as I revved it. After warming up it got better, but now the idle dives down too low after letting up on the pedal. After cleaning do things have to re-train it somehow? If so do you turn PSM off for a while? I will see how it is after blowing it out tomorrow. There is also a definite oil leak somewhere on the left front region of the engine. Hard to get a good picture, but this is looking forward from the sway bar mount on the driver side. I really hope this runs better and not worse now!

Failed...I don’t know what was up with the last people that worked on this vehicle. You mentioned it looked part way out already, but I haven’t moved it in the least. I think they couldn’t get it back together all the way and just forced it on the best they could. I have seen that theme with other work that was done on this e.g. all the plastic that was cracked and broken under the headliner that I saw when I did the hatch shocks. I think my only option is to remove it from the turbo end and get it onto a workbench. At least that should be plastic on steel.

Excellent - thanks guys. Working on it now...

Thanks - so is it supposed to separate at the seam under the clamp? I used WD40 and tried for an hour to pull these apart and they won’t budge. I’m not used to working with plastic parts like this....trying to pry it apart and just gouging things up.

Finally found a set of pentalobe security drivers with a TD25 in town and started on this. I was thinking these questions were kind of lame, but in case others search in the future thought it might be helpful for somebody. So my problem now is to get the drivers side MAF out without breaking anything. Although I can get to the screw holding the MAF in with extensions, kind of, this would be a lot easier if I could remove the air flow tube. Problem is I don’t want to torque on the housing, because the flex pipe that attaches it to the turbo underneath seems quite flimsy and the housing is really seized in there. But if you do separate them, is the arrow where they come apart? Second point is to get to the pentalobe screws holding the MAF in, it would be much easier to disconnect this line (arrow) This I assume (without a manual) is the upper rad hose - can I disconnect this when the engine is cool without draining some coolant out first? Or will it gush? A bit of an aside, with all this open I can see I do have an oil leak from somewhere under this area. Plus I think there is something else sub-optimal here; as I get used to the engine, I’m realizing I get better acceleration if I short shift it, due to the boost dropping off early. It peaks at maybe 4500 rpm, but then drops off fast after that. Will work on it more tomorrow. Cheers.

Finally went to clean the MAF sensors; minor questions – to get out the air tubes holding these is easy on the normally aspirated engine, but the turbo sticks them down at the sides. Do people take out the whole air tube to do this, or just unscrew the sensor? Looks like getting to the inner bolt on the drivers side is a bit tight for room.... Passenger side is better Also, can you clean the pressure sensor with MAF cleaner as well? If not, just carb cleaner? Or not to bother? Also, if you unplug them (with the engine off...) do you have to reset any codes afterwards? I still don't have a OBD2 working yet, and will probably clean them attached if there is a risk of that. Thanks!

Been working for several days solid; have had no time to do anything on the beast. But great write up, thanks lewisweller, sounds like you are making progress! I hope to get at this in a few days.

Great info indeed; lewisweller, thanks for all the help here. And hah! I found the correct T (perfect zoom on the correct line), right there under the intake pipe. No leaks on the DV’s. I will test the waste gate opening, but first I have to get a better regulated pressure source – I just have a huge air compressor and I don’t trust the accuracy of the pressure regulator that low. Going over the maintenance records again I see that a few years ago they detected a “minor vacuum leak in the waste gate actuator” which was causing some misfiring. Maybe that is happening again. The whole idea of limp home mode is unsettling, and I still don’t have a Durametric cable. But in the mean time I’m charging up the GoPro and will film a clip of with the engine sounds for fun.

Thanks - mine does have its fair share of strange sounds. I think the "honk" noise could be there; what was interesting to hear was the other post with the videos of the exhaust system install. Mine sounds similar to the fully modified version from the outside, but quite different inside. Most notably is when the wastegates open there is that classic aftermarket turbo loud air release sound. But again I am not sure of all the mods that were done to mine; maybe there is a different blow off valve setup or something. I need to take a look at my wastegates, DVs and turbos and see if anything is not stock. I tried your test – to bad you can get manuals so easily for all other Porsches except the Cayenne; I have to go over the parts fiches some more to figure what is what. Mine is set up a little different. I believe the red arrow points to the T as in yours – I disconnected it from the solenoid it goes into at the green arrow and blew – there is no leak really, but you can feel what seems like a diaphragm flexing a bit as you increase pressure. Didn’t want to blow too hard and damage something. I took off the line with the blue arrow that also goes to that solenoid and air just free flows through there; I assume that is the vent? I have to go over the diagrams and learn what is where on this. I will try and take a sound clip of it accelerating and post it. Thanks again.

Thanks, much appreciated. I think I will take out the tub this weekend and make sure everything looks OK. It’s running pretty good, but there is a kind of fluttering sound when the turbos are at work that I haven’t heard on other turbocharged engines.

Well I seem to have solved this, in case anyone ever wonders. I did figure out where the flex pipe is (that explains the flex...) and that the catalytic converter is not where I am used to finding it so the turbo is probably fine. It seems the rubber grommet supporting the exhaust is worn on one side and has a lot of play; it has the Fabspeed Turbo Maxflo exhaust system on it, and the alignment of everything is actually not that great. Anyways for testing purposes I jammed a bolt in the grommet to take up the play and the knocking went away. Easy fixes are so great. But I am still curious if anyone has DIY’ed their turbocharger with the engine in; also looking at it more closely, can you see the turbo if you take out the wheel tub plastic? Seems like you might be able to get access that way.

A few questions regarding the turbochargers - there is a tapping sound that comes from the driver side under WOT; it was there for the previous owner as well, and I am pretty sure it is something in the area of the turbo hitting the frame or similar. PO had a new exhaust system put on hoping it would help but it didn’t. When you go under the vehicle and bang on the large exhaust flange where it exits the engine compartment, the passenger side is solid, but the driver’s side moves a bit (~1/4 inch) and you can hear it hit something, thus I assume the noise. Questions I had: 1) Does play at this point suggest something is not attached well upstream at the turbo? Or is there supposed to be some flex in the system? 2) I can’t see up far enough from underneath to see the turbocharger - how do people visually inspect the turbo? Are you supposed to be able to see them after removing the air box? I have a cold air induction system and things are different in there on mine - if I take it all out should I be able to get a visual on it? 3) Seemingly unrelated but maybe not, there are 2 wastegates, one on each turbo, that act independently, correct? It seems that I only hear one on the passenger side opening. This, combined with the looseness has me concerned that something isn’t right on the driver's side. But the engine runs pretty smooth and the boost pressure goes high as it should. 4) I’ve looked at the DIY turbo replacement by SpawnyWippet here and on Rennlist; has anyone else successfully replaced a turbo without dropping the engine? Thanks for any feedback.

Sounds like reason enough to post pictures of the beast! I do get it dirty sometimes...this is with the 20" winter wheels on. Still trying to figure out what the S really means on my specific vehicle - but the positioning is correct... This is with the summer 22" wheels and spacers.

What I need to do is get a Durametric cable...I bought the cheap Chinese version locally because I needed it right away, but I can’t get it to work, either because of trying to get a Win XP laptop running again or the cable is just broke. I also need to run more tests…it only does it after sitting overnight, or on colds days after sitting at work. This morning I gave it WOT before cranking and it started in 3 seconds. But I don’t think the throttle by wire pedal pays attention to pressure the first crank anyways. So more tests to come. I also have a cold air induction system and an aftermarket exhaust; I thought they re-mapped the ECU to compensate but maybe they didn’t do a great job. I was at a pro-tuning shop though.

I hit 21 mpg the other day - but I did have a tailwind! So another update; the non-alcoholic gas helped, but now the cold weather is coming, it’s getting harder to start again when cold. Like a full 8 seconds of cranking before it catches. Like the automatic choke of days gone by isn't working. Instant start when warm. Runs perfect otherwise, except it gets a slightly rough idle sometimes, which goes away after I nail the throttle a few times. No problem starting after filling up the tank, or any of the other things that get mentioned on line. Going to try injector cleaner, any brand recommendations? I'm in Canada. Thanks.

Much larger range than I've seen with other vehicles actually. But I did do some tests after getting flack from my Prius driving friends; so my average reads as 13 mpg, but on the highway at 70 mph with cruise control it can actually get 21 mpg. But when I wind it out it can get as low as 10 mpg.

Wow, thanks bigbuzuki...this make a lot of sense; going to go over this in detail. Much appreciated!

Yes, you are correct, of course...from what I can gather, this vehicle was a special order; apparently in 2004 if you threw horrendous amounts of money at Porsche they would build in whatever options you wanted, and the original owner wanted an S engine and got it. This info came from a Porsche dealership based on the VIN, and I have seen reference to one other similar vehicle online. Although I have all the maintenance records, I don't have the original invoice, so I can't be sure; but other than saying Turbo S on the back (which I know doesn't mean much), it will peg the boost gauge (0.8), and then fall back to just a hair under 0.8, and it has the larger brakes and the stock rims are 20" (I have 22" wheels on it now). So it probably more accurate to call it a CTT with an S option rather than a CTTS. Either way, it was built this way by Porsche I believe, and it goes pretty well...

Just a follow up - I know this is all pretty trivial compared to the issues some people are having here (yikes!) but just wanted to let people know that running 94 octane with 10% ethanol seems to have been the problem. Some Shell V-Power 91 and it starts like it should again. This is in Canada, and our mix is a bit different up here; it's also in a 2004 Turbo S, in case that makes a difference.

Thanks – I tried a tank of Shell V-Power 91, supposedly without ethanol and it was a bit better this morning. Also going to use this as an excuse to blow it out a bit (). I’ll post back after another tank and I see if that was the issue. If not, yeah, it seemed like when the check valve on a fuel pump is letting everything drain back into the tank. I still goes great once it starts! I don’t have a proper Durametric cable yet, but might pick up one of the cheap Chinese versions tonight and at least see if it is throwing any codes.

OK, so I guess the honeymoon is over - my new to me 2004 CTTS is now taking longer to start when cold. When warm it's usually 1-2 seconds, but after sitting over night it can take around 5-6 seconds. Didn't do that when I got it 3 weeks ago. Is this normal, or should I be checking fuel rail pressure and such? Also it has started running rough at idle after I have been dogging it around the city, but runs smooth at idle after I blow it out with some hard acceleration. Another thing is I switched gas lately - I think we have less choices here in Canada, but I went from Esso 91 to Husky 94, which I thought would be better, but the 94 does have 10% ethanol. Could that contribute to the longer start times? Thanks!