Hi guys,
Im hoping some of you can shed a little light on whether this is a normal charactoristic for a 997tt engine to start from cold.
I find that on the odd start up, mainly from cold first up in the morning or last thing in the arvo when its time to go home that when you turn the ignition key to start, the engine instantly starts and revs itself up really high for a nano second and dies immediately back down to where it sits on hot idle rpm for 30 seconds or so before then again dropping back to the warm idle revs which are ever so slightly lower again. The engine note also quietens at that point which is obviously normal. I find that when the engine does this high rev up thing its as if it revs at least over 5,000rpm so its not just a minor spin up. for me its a little concerning when you consider the oil film has probably diminished from previous use prior to shutdown cool off etc so im very curious how do other owners 997tt's engines start?

Do any of you ever get that odd occassion when the engine spins itself nearly off the tacho at half a turn of the starter?

Mine did this again this morning but i reckon this time it actually hit the redline limmiter and then what happened immediately after was a CEL and a chime indicating engine warning on dash. Its now in the dealer at the moment (for a front diff changeout) but they didnt appear all too concerned...as if thats fairly normal for one of these. They said they will dignose the cel and reset it but i'm more interested in why it revs up like this and moreso now that its thrown a cel.

Your thoughts would be appreciated..

 

no something seems wrong, 5000 rpm is high

 

Agreed. Mine does it noticeably but not to 5K. I'd get that checked out.

 

Mine revs on startup to around 3k between 5-10 startup.
I a told this is normal, it does seem odd and not good on a cold engine.

 

its normal, mine does it on occasion. may need intake cleaning, throttle body, as I read that can be the culprit.

 

this issue has been brought numerous times in the past and i also had the same issue in my previous 07 MY, BUT never anything higher than maybe 3500rpm... the dealer should be able to find the culprit with the cell on so keep us updated

 

occasionally mine will start up with a nice vroom but never over 3k rpms. I assume you aren't accidentally nudging the throttle while stepping on the brake while you are starting the car? The pedals are fairly close together but you'd have to have BIG feet for this to happen!

 

Yep thats my thought especially now the cel kicked in. Admittedly i wasnt looking at the tach at the time but it sure sounded like it was way up there in the rpm dept.

Have you ever been lucky enough to be looking at your tach when its done it on yours? If so whats been the highest its hit?

Yep, the thought of this type of rev up on a cold standing engine doesnt make feel too warm and fuzzy either.

Agree and now that cel going off.....pretty well confirms somethins cookin.

Thanks for the tip. I'll mention the throttle body to P. When you say cleaning is it that you can see its dirty when you remove the Y pipe and look at the butterfly?

Definately will. Hopefully will have the facts at one point this morning. I'm hoping its nothing too serious.

Nope. left foot on clutch deepressing to floor, right foot nowhere near accel pedal. Turn the ignition key... and vroooom.

 

Verdict time on the cause of CEL!

Ok...just picked her up from P Dealer and aside the new front diff change out she got...which thankfully this time works perfectly with no vibration etc the engine CEL was diagnosed as a faulty oxygen sensor connection. The fix requiring only for the connection plug in the engine bay to be snap locked back into its mating connection. It was found not fully home if only by a wisker so the snap lock fitting hadnt properly clicked up stopping it coming apart.
The P service guys said the occassional rev up on cold start is inherent and quite normal for the 997tt so for those of us with any concerns im officially told by P we can all sleep easy. They did say that if there is anything slightly out in the engine sensors the computor compensates in its own way and that can cause the rev up to be higher than normal too which is why mine really revved up higher than it ever had, throwing the CEL etc. As the plug is directly in the engine bay the vibrations from the engine running have worked it off slightly to a point it lost proper contact with its mating connector plug sending only an intermitant signal to the ecu hence the CEL activating. There you have it...
Anyways id like to thank all you guys for giving me your thoughts...its appreciated. Thanks again .

 

i've had mine do a "high rev" start up a couple of times. never noticed the tach but will look from now on. good to hear it's not an issue as the cold start sound of my FVD exhaust in the garage sounds wicked - especially at higher revs

 

+1 "high rev" start up a couple of times.

 

Got a high rev on startup this weekend, but it was only to ~3.5K. Just FYI.

 

Keep an eye on it. If it throws a cel then you know you definately have a problem the ecu cant compensate for. And the FVD, i reckon my EP will give it a very serious run for its money in the snap crackle and pop sound dept on cold start . btw E55 that slate is a real winner with those 67's....very tasty combo.....but hey i'm biased with the 67's .

Normal...but if it gets too high and frequent then it means somethins cookin. Thats how mine started out.

Its cool. Hey now mines been cleared the most she has since managed is 1800 but usually starts now just above hot idle. Yours may just need a good fanging to clear off the sensors. Sounds a good excuse to give it some welly .