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Well the car hesitated in 2nd gear for the first time since changing the hose
Well dang dude. I was excited about your fix, but like so many other cars, it comes back. I have simplified thread response #2 above to one list - your oil vent hose is #8 I think. I added #21 which is what I'm leaning towards at the moment. I hope to be proved wrong.
Chrono -- It's been a few months since your issue . . . has the hesitation resurfaced at all? Do you think it was due to running gas with ethanol in it? Much appreciated.
Any updates on this? I am experiencing the same issue. I think it may be related to the winter gasoline blends as it just started happening during the cold weather.
I am doing a full service next week (spark plugs, coil packs, etc) so we'll see if that has an affect.
I don't think there's a confirmed fix for this, partly because it's so hard to describe the problem and the people who experience similar issue might not be exactly the same.
For my case, it can happen when cold or warm, sports mode on or off.. etc. The problem usually goes away after 30-60 mins of spirit driving on weekends (mine is a semi-DD and I only drive it for about 10KM per day between home and work). I also got into habit of disconnecting the battery every few month and the car does get more responsive.
Any updates on this? I am experiencing the same issue. I think it may be related to the winter gasoline blends as it just started happening during the cold weather.
I am doing a full service next week (spark plugs, coil packs, etc) so we'll see if that has an affect.
- Harvey
It's been one year almost to the day since I started this, and mine still exhibits the phenomenon on occasion, today as a matter if fact.
Early on, some of the episodes were from my own driving style, coming from manuals, I wanted to use my left foot on the brake, which will give you a horrendous lag if you mix throttle and brake even for a fraction of a second.
Most other stalling and surging I have attributed to my driving style while in the city. The car NEVER stalls when I drive it "right". It just doesn't like me feathering the throttle in traffic.
I've found that resetting the throttle mapping, by disconnecting the battery for a while, helps if I've been doing many hours a week of city driving.
If you read that, thanks, but no real cure yet. Maybe because there's not a illness.
I am not 100% sure if my 997.1 (2005) Tip's problem is related to this issue. The car acts the same way as mentioned over the last few months. 1st, thought it was the electrical issue, had it checked, wasn't. Then check vacuum leaks, wasn't too. Finally brought it to local dealer, it was claimed to be the Tip program which they said it was updated and reloaded. Got the car back 2 weeks ago, problem appeared to be solved (I thought), then the next morning when the engine and gearbox were cold, same thing happened (but not as bad). So, took the car back to dealer and explained clearly on what has been happening. This time, the technical person claimed that the tip program used for this region appears to act like this for the same year model and they told me that they used to fix the problem with Tip program from other region.
However, they also claimed since the car is 10 years old, programs are no longer available and they have to find out what they can do about it. Luckyly they said surely nothing mechanical related. I have to leave the car with them for a week to determine what's exactly wrong with it before they get back to me.
My MY2007 2006 997 Turbo has started doing this recently. At first I thought I must have been resting my left foot ever so slightly on the brake pedal (I left foot brake), as the symptom feels exactly the same as when you brake whilst still having the accelerator on - car goes into limp mode.
It seems to do it from very slow speeds or a stop. Lifting off the accelerator and immediately getting back on it restores acceleration.
Could it be that the car is reading as though the brake is engaged even though it isn't?
Spent 20 minutes today trying to recreate the problem and found the following:
Issue appears after depressing the brake and then releasing it. This can occur either after pulling away from a stationary position, or after braking but not coming to a stop.
Also found that the car isn't always going into limp mode when both the brake and accelerator are depressed. After lightly (10-15%) braking whilst accelerating lightly (~10%), and then releasing the brake, it can go into limp mode, even though the accelerator remains depressed.
When the issue occurs, tapping the brake restores acceleration, without changing the accelerator position (remains depressed).
The findings above indicate a problem with a sensor in the brake system. Reading other threads, a common fault relates to the brake switch sensor. I'll replace mine I the hopes that this resolves the issue.
When I first got my 2006 C2S Tip, it hesitates at about 1200RPM. It usually happens (or more noticeable?) when I press the gas panel harder, and I don't notice this if I press down very gently / slowly. it can happen either when the car is idle or accelerating from stop, no issue when cruising as its above 1200RPM.
Interesting. Is it also hesitating at 1800 RPM like my 997 GTS does? I can replicate it at will after overrun followed by light acceleration at both 1200 and 1800 RPM. See this thread: https://rennlist.com/forums/997-foru...l#post12647910
Well this happened to me today, and having gone through all the related threads, there doesn't seem to be a clear fix. And yes, mine's an 06, C4S manual. Mystery continues.
2005 Boxster 987, just started having this problem. The reason I'm replying now is that the first time I felt it was while in the middle of a U-turn and OP said it seems to happen more often *while turning*. How true.
Background: AOS failure, appears to have been for quite some time before the diaphragm really ruptured because performance had been suffering gradually for months (obvious only in hindsight), until finally plumes of smoke showed up. Replaced AOS, oil throughout intake manifolds. Cleaned them out lightly and reassembled. Performance great, smoke went away, but now the shuddering/hesitation problem shows up, the first time ever (owned the car 2.5 years), exactly as described by OP and others here.
The way it feels (I have some experience with this on a 996 with unreliable engine connector after a rebuild) it seems to be an electrical control issue because it's so sharp, i.e. not a fuel related issue (except for injector control); could be ABS/PSM related or transient "limp mode" turned on or something like that, e.g. DME thinks both gas and brake are depressed at the same time or PSM is getting wrong inputs when at or near idle.
As part of replacing AOS, I disconnected the throttle body connector (and the small vacuum lines in the secondary air injection system) and lightly cleaned the throttle body, so that may have been affected.
After replacing AOS I cleared all faults, and now Durametric shows 4 faults:
Here is the diagnostic info from the manual for P2187, indicating it is related to instability or other issue near idle:
It's actually the wife's car and she said yesterday when it happened to her that gunning the accelerator eliminated the problem and she drove the rest of the way home without issue.
In any case I am trying:
1) Reseat gas and oil filler caps
2) Re-initialize throttle positioner (40 seconds according to the manual)
3) Will buy a MAF cleaner and try that if steps 1 and 2 don't help
4) Maybe try disabling PSM
Otherwise failing MAF or oxygen sensors may be the next steps to investigate, although the codes don't seem to indicate MAF failure.
1) Reseating gas and oil filler caps and resetting throttle positioner did not change anything 2) Disabling PSM produces a major improvement, but not 100%
I am also wondering about the P2177 and P2179 codes I got with "checksum error". This is a Durametric code description so it may or may not be correct (this detail does not exist in the '05 987 diagnostic manual for this code). But I assume that a checksum error is generally indicating data corruption. It would appear that the DME is getting mixture adaptation data that it detects as corrupted.
The problem I had with my 996 was much more serious and was eventually tracked down to corrosion in the main engine connectors, resulting in lots of bad data sent to the DME. Additionally a short time later the throttle positioner connector developed the same problem. A thorough cleaning of the connectors was the fix and the car has been flawless since. May be similar here. I think that when 10-12 year old connectors are taken apart and reassembled there is opportunity for poor contact as the conductors will shift slightly relative to each other when reinserted.
Resolution on my issue: took the intake system apart including the MAF, which clearly had some oil on the plastic holder and oil pooled at the bottom of the tube. Cleaned the MAF and all the tubes between air filter box and up to and into the air distribution tee and manifolds with CRC MAF Cleaner. Cleaned throttle body and MAF connectors with the magical DeoxIT DN5 spray. Put it all back together and has been flawless for a week.
Lesson: AOS diaphragm rupture requires cleaning the entire air intake system. And use DeoxIT when reassembling connectors.
02-08-2014, 11:48 PM
