Sluggish 996TT

[996 turbo]

Guys,

I've just got my car back from it's small service at my OPC and it feels a bit sluggish. Well not really sluggish but it doesn't have the instant response to the throttle it used to have. A bit like turbo lag, boost pressure, oil pressure and temperature all seem as they were but the car feels wrong. There is also a very black colour to the tail pipes like it's running rich (they used to be dark grey).

Is there anything they could have done which would effect the performance / throttle response during such a small service (Basically a £400 oil change)?

Steve, 996TT

>>> Edited by 996 turbo on Tuesday 6th July 18:36

[GuyR]

Black smoke/tail pipe indicates rich running.

This and a sluggishness is usually caused by an air-leak in the system from a badly fitted hose............

[911habbit]

Give it a good run m8, it should clear itself if all is fitted ok.

The ECU does seem to adjust to the driving use, if the OPC have been 'poodling' about in it may just be running on a bit of an economic mode or something.

I’ve experience the car feeling different after OPC services, always seems to settle down after a bit of a blast.

[ewan oozarmy]

That's exactly why I stopped taking my 993TT to OPCs - you're pride and joy should run better after an expensive service, not worse.

[aceparts_com]

I'm with the above on give it a blast.
I had my Air conditioning cleaned yesterday which smelt so bad that I had to drive home (30 miles) at less than sixty with the windows open so as not to pass out due to the fumes.

This morning the car sounded like a box of bolts in cement mixer! This is not the first time i've noticed this after 'steady' driving. Car just needs a good cane!

[pdV6]

GuyR said:

Black smoke/tail pipe indicates rich running. This and a sluggishness is usually caused by an air-leak in the system from a badly fitted hose............

Depending where it is, might an air leak might fool the sensors into thinking the fuel mix is lean... leading to over-enrichment?

[MOD500]

Remember reading a 911 World or GT mag a few months back and a chap was complaining of rough running in his 996TT, it turned out some part in the airbox had collapsed or something. Hence stranging the engine, especially at high revs.

HTH


MOD.

[996 turbo]

Cheers for the replies,

I'll give it a good run at the weekend then decide (something). It does seem to point to running rich for some reason. But I can't imagine what they would have touched / broke. Normally I'd just put it down to being paranoid or something. They did however, run it into their ramp causing a days delay and some plastics at the front to need replacing. They were very non-specific, kin-MUPPETS! so I'm thinking anything is possible. I might end-up taking it back to G-Force for a quick check...But what can I say if it's back down to standard power?

Does anyone know for sure if they have a learning ECU?

Steve, 996TT

[grant3]

The ECU is adaptive, so if (like me) part of daily drive is a slow "follow the leader" it can affect the cars instant grunt.
OPC says , disconecting the battery re-sets the ecu & makes it frisky again, but you have to leave the car keys in to avoid the alarm deafening you & ensure you have radio/pcm codes ! Alternatively if it has been re-set at the dealers it may be re-learning your cargraphic system.

[clubsport]

grant3 said:

The ECU is adaptive, so if (like me) part of daily drive is a slow "follow the leader" it can affect the cars instant grunt. OPC says , disconecting the battery re-sets the ecu & makes it frisky again, but you have to leave the car keys in to avoid the alarm deafening you & ensure you have radio/pcm codes ! Alternatively if it has been re-set at the dealers it may be re-learning your cargraphic system.

Take Grants advice above ref security,
to succesfully re-set..you need the car to be running hot not just warm, then turn the car off...leave the battery disconnected for 5-10 mins,,,,reconnect than let the car idle for 5 mins or so, still hot...then take it out and apply the heavy right foot to accelerator pedal for a few miles this should adapt the new characteristics to the ECU...have fun!

[911 habit]

How's going now? Given it a blast yet?

[996 turbo]

911 habit said:

How's going now? Given it a blast yet?

Been out for a proper drive this morning and I'm not sure what I think. It still feels different, not slow extactly but...It's like a hole in the mid-range or something it doesn't quite pin me in the seat like it used to. It still seems to be doing the same speeds down my favorite roads. It's weird, I'll have to put it back on the rolling road to put my mind at rest.

It's got a oil leak since the service now, looks like the sump plug dripping quite a bit. So it look like I'll be going back to my OPC...They've already told be I must be imagining the power thing.

Steve, 996TT

[911 habit]

I've been using my local OPC for 4-5 years now, what has really worked for me, is identifying the top specialist, i.e. the top turbo knowledge in the OPC workshop - just talk to the techy, not the workshop manager, bounce your ideas/feelings off him, get him to check the onboard computer logs and the "fly-by-wire" throttle system etc. If there is an air leak it will show up in the error logs.
Good luck & let us know the outcome.

[996 turbo]

911 habit said:

I've been using my local OPC for 4-5 years now, what has really worked for me, is identifying the top specialist, i.e. the top turbo knowledge in the OPC workshop - just talk to the techy, not the workshop manager, bounce your ideas/feelings off him, get him to check the onboard computer logs and the "fly-by-wire" throttle system etc. If there is an air leak it will show up in the error logs. Good luck & let us know the outcome.

First time i've used this south Birmingham OPC. But getting to actually speak to the mechanics is nigh-on impossible given the layout. It was only the minor service (basically an oil change) so I'm guessing the spotty youth did it. Even so it's hard to imagine what they could have done.

Mind you it was a day late, crashed in a ramp and generally mis-treated they even got the number plate wrong on the bill which was over-charged BTW. I'm writting a letter tonight and will post the outcome for anyone who's interested.

Steve, 996TT


>> Edited by 996 turbo on Tuesday 13th July 15:42

[grant3]

Aside from the ECU issue affecting performance (this worked for me), I have to say that mine seems variable as well. I think a lot is down to air temperature density/humidity with the Turbo & intercoolers. One day you hange onto the steering wheel , the next it seems less agressive, although the ohter half always says "It's bloody savage2 what ever I think.

[911 habit]

I just found Grant's old link:
www.pistonheads.com/gassing/topic.asp?f=48&h=0&t=58793
A bit more info on ECU life.

[Úbermensch]

996 turbo said:

.. causing a days delay and some plastics at the front to need replacing. They were very non-specific, kin-MUPPETS! so I'm thinking anything is possible. It's got a oil leak since the service now, looks like the sump plug dripping quite a bit.

you might just wanna check that your engine number still corresponds with the registration documents.. [/paranoid android mode]