3rd gear, 2500RPM loses all power

ive had my car go into limp mode before, but this seems a tad different. this seems to have more power than previous limp modes...but maybe im wrong.


but recently, the car has been going into limp mode/losing boost around 2500rpm, 3rd gear, almost every time.

runs great in 2nd and 1st. power and boost throughout the whole range. once I hit 3rd, 2500RPM. shes done for. bye bye power. I can still slowly limp it to 70 mph with some downhill sections and lots of time. but its no fun. turning car off and on fixes this... till I hit 3rd again. once in a blue moon it seems to randomly fix itself, and ill get boost back while limping along in 4th or 5th, then itll go away again. its been doing this for 5 days now.


did some research and figured it could be 3 things. ill start with easiest first.

1. disconnected piping by passenger wheel. easy fix. I think this has happened to me before, but never sent me into 2500 rpm, 3rd gear limp mode.

2.MAF sensor (and air filter if it is the MAF). im sure this is easy enough to find and tinker around with. I read to unplug it and take it for a drive to see if itll kick into limp mode. id also like to point that my mileage seems to suck lately.... also pointing towards MAF sensor. right?

looks easy enough to find: does this seem like too good of a deal to be true?? $40 for a bosch MAF???

https://www.ebay.com/itm/NEW-BOSCH-...ash=item211e26e381:g:4wwAAOSw2xRYd3rx&vxp=mtr

if unplugging the MAF and checking that intercooler piping doesnt help, ill check the vacuum lines. dont know really where to start there, seems a tad tricky but im sure once I look at it itll be obvious. if its not that, im all out of ideas.


any other things I should check while im there?

Piping by tire are fine.

Unplugged MAF sensor while it was running and it seemed to make it a little better while driving afterwards. Turned the car off and it would not fire back up with MAF unplugged. So I plugged it back in

Have you replaced your fuel filter recently? Plugged filter might reduce fuel flow... Did you check the air filter when you messed with the MAF?

Fuel filter is about a year old. First gear runs great. Power all the way and doesn’t kick into limp mode. 2nd and 3rd it’ll do it in now.

I did not check the air filter either. It’s about a year old too. I remember reading if you open to look you should replace as they only seal once kinda deal. It’s my turbo kicking off. I can hear the boost whoosh and everything go away. No smoke though. Just limp mode. But half limp mode. I still got more power than the limp mode I’ve been in before.

watching your thread, just saw this, kind of like mine but yours seems more boost related from reading, maybe not.

mine is hesitating past 3k and gets more pronounced as you go up through the gears.
cant rev past 4k or so at idle def wont touch the red period.
i was able to check my boost on vagcom and am pretty positive it is not leaking. MAF seems to be fine also.
will watch here , post when you figure it out, i will do the same with mine.
thanks

Will do! Maybe I’ll see if I can get my knockoff vcds to work today and tinker around with it. I’ll keep you updated. Otherwise she needs to see a shop real soon

Ok. Vacuum lines looked fine from my quick amateur inspection. Today it’s bright and sunny and I climbed a slow steep hill from a stop sign with the sunlight just right and I was blowing so much black smoke!!


My turbo is shot isn’t it... it loses boost about half ways up and goes into half power mode. Feels Stronger than limp mode.

ok, changing summer tires I was able to look closer and found this... fixed it. car feels a bit better, but still feels weak, and it shoots a medium amount of black smoke after 3500RPM (ive been running it hard and testing it). the turbo "whoosh" is also super loud now. going to pull codes when my friend gives my code reader back... will a generic OBD II code reader work? im pretty sure it has on my car before... cant quite remember. its been a while since ive needed it. 2 years almost.

Generic reader might tell you something, but often misinterprets some of the codes unique to the TDI. They vary.

Fixed is relative . . . as bad as that looked, you may well still be dumping boot under high power . . . (that's certainly what the black smoke indicates - overfueling due to inadequate air/boost . . . ).

yeah the hose popped off again. there is oil leaking from the bottom of the boot and intercooler thing by the passenger wheel.

whats going on with my car? that belt is also pretty hurting... I gotta bring it in ASAFP. I am 75% of the way towards needing a new timing belt too. I did it at 190,000km and im at 290,000 right now in 2 years. it needs a lot of work coming up here doesnt it.....

is it part 7 I need here? conveniently the only one without a part number??? is this gonna be one of "those" fixes already?!?! :banghead:

https://parts.vw.com/a/Volkswagen_2...2232/INTERCOOLER-W100-HORSEPOWER/9277075.html

fouillard13 said:

yeah the hose popped off again. there is oil leaking from the bottom of the boot and intercooler thing by the passenger wheel.

whats going on with my car? ..................................

Click to expand...

Your intercooler and piping needs a refresh. Also check the oil lines to the turbo.

ok finally got to scan the car with my generic scanner. seemed to work fine. I got 12 codes. cleared them, re scanned, and then for 2 main codes. the EGR ones been there forever, but the other seems to be quite important:

p0101 = mass or volume air flow A circuit range/performance
p0128 - coolant thermostat below regulating temperature
p0671 - glow plug cylinder 1
p2413 = EGR system
P0299 = turbocharger underboost condition
p2564 - turbocharger boost control position sensor circuit low
and a few were duplicates.


cleared all those, and these 2 came back:

p2413 = EGR system performance
p2564 = turbo boost control position.

I did some googling on the p2564 and it seems that the wires could be corroded or chafed, so im going to take a look at those today and go from there.

the intercooler piping also needs to be replaced down by the passenger tire. whats the best fix for that? order all new OEM stuff, which im having a hard time finding. or cut the culprit piece out, and slam a piece of 6" long intercooler hose/piping in there with some hose clamps and call it good?

I have a Crafter which caused much angst for some time . Ross tech VAG-COM tested P0299. It would run up to 75-80 kms them fault and eng check and glow light would come on. Press tested induction pipping to 20psi . All ok. B. Realtime monitored road test showed boost rolling off. Vacuum control vavle for turbo tested and found faulty. Replaced and will now do 120kms in 6th uphill. Happy days esp when VW dealer and others couldnt diagnose.

Good to know. Thanks for the answer. She’s going to the local mechanic today. I give up.

local mechanic did a hell of a job. he does VW only stuff so finally someone who knew what they were doing!!!


replaced the plastic intercooler piping down by the passenger wheel.
replaced the tandem pump gasket
tuned the car, and deleted the EGR light.
changed serpentine belt.




the car runs awesome, its never started so quickly. it used to crank over a few times, then run like crap for 10-15 seconds. now its instant start and purrs nicely. runs great too, lots of power. light smoke haze sometimes which is meh, I try to avoid it.


he said my clutch is starting to slip. 300,000 km for me is coming up and im planning on doing a few things at that point. clutch being one of them. figure I can do it myself and save a few hundred bucks. maybe, well see when I get under there!

Victory! Thanks for posting back.