Strange loss of power and cruise control

[Dyldo]

Hey oilers! Long time in between posts as I mostly drive my Bora. OK, so as best as I can remember here's what happened today to my Mk5 Golf TDI. Was on a long-ish drive with full tank, and just about to go up Mac Pass (anyone in NSW knows its a mad road) and hit a roadworks patch just before the climb. so obviously touch the brakes and the CC comes off as you'd expect, but when i go to accelerate it lags and bogs and goes nowhere.

I don't feel the usually torquey push or hear the turbo whine up. Flat to the floor now and no increase in power. Change gears and still no change. Ends up being maxxed at about 3,600rpm at 70-80kmh up a hill. Basically a laden removalists truck was beating me.

There were no engine or dash warning lights at all. No stuttering. Didn't feel like a cylinder was dropped, nor was there excessive smoke or fuel consumption. Everything was largely fine other than the obvious. No change of accessories did anything (lights, stereo, AC, etc)

After a 20min rest i got back in, she started fine, no issues, rolled back and saw no droplets of anything on the pavement where i was, and then sure enough took off and had all the normal power present and could hear the turbo spool up into a nice whine.

Thoughts?

[gldgti]

maybe the vanes on the turbo got stuck in the open position, so you had no boost. maybe when you stopped it cooled a bit and they were able to move again.

[Dyldo]

thanks gldgti, but can't be. Happened again today from canberra (damn cold) and then again after i'd gotten into my car after driving only 2 mins and hit cruise control and BAM loss of power.

I also noticed i could rev only to 3K in neutral when the car was behaving normally, but when the car was in its "loss of power" mode i could rev freely to redline in neutral.

I've found the only way to get my power back is to turn the keys off and then back on again.

I say CANBUS issues again.

[Dyldo]

Anyone?

Am i in some sort of limp or valet mode?

[Dyldo]

or could mine be EGR related?

http://www.vwwatercooled.org.au/f28/cleaning-egr-inlet-gt-56086.html

[passatstef]

i know that the bora and the passat had the same problem.it`s like its forgetting to think and scratching it nuts and them it go`s oh yeah i better to accelerate.is yours doing that mate.?

[Dyldo]

nup, once it happens it stays that way for ~kms until the key is switched off and then on again. I've even done it on the fly once, but thats not good.

[Angryman]

Mate had exactly The same problem with my gt sport last year. Turned out to be a faulty speed sensor and some thing called a crank angle sensor... as you described it was exactly what I had. Took it to service and it was gone for four weeks as they had to get help from the motherland! It was a major pain in the add and will eventually put you into limp mode permanently. Best get it in to see if any codes throw up

Sent from my HTC Desire using Tapatalk

[Dyldo]

mate, best answer i've had yet. gives me something to give to the vw techs in case the spend the 4 weeks trying to find their puckholes.

I've got no CELs or lights on dash yet.

[CustomSpooling]

Do you have VAGcom?

It sounds like a faulty N75 valve (on MK5s it is a black box the size if not bigger than a CD case)

It can also be alot of other things. If you do not have VAGcom then go get it!

[Dyldo]

Booked in at McGrath Liverpool (well, not exactly booked in as they claim to be under the pump) so we'll see. Hope it doesn't take 4 weeks though....

I have a fully novated lease through Fleetpartners, who claim to have priority service slots at VW, so why is it every damn time i call up for servicing i get pleb treatment? whatevs.

So, out of speed sensor, crank angle sensor, canbus, N75 and random gremlins where would folks put a betting dollar?

[ForceFed]

Wow this is amazing. I bought my 2007 Golf 2.0TDI last week and this has happened to me also. Boosting hard one day dead flat the next, checked the car for boost leaks but couldn't find any, no CEL, disconnected the battery to see if it would reset the ecu just in case it was in limp-mode. Still not fixed. What to do???

Great start to owning my first VW

[ForceFed]

CogDoc feel free to jump in with your suggestions.

[h100vw]

I reckon we need to see some boost logs from a standard car that is working ok and then check the bad cars against them.
Gavin

[Transporter]

I reckon we need to see some boost logs from a standard car that is working ok and then check the bad cars against them.
Gavin

You're more than welcome to go for drive with me to take the logs, the car will be home on Saturday morning.