not boosting again!

[GTi_Red]

this is the second time this has happened, the first time it just started boosing again after a plug in, code clear.
this time started on my way home from work so ive looked for split pipes, cant see any ive had the diverter valve(standard bosch one) off to see if its sticking open and its not i can also hear the dump through the 57i. when footing it it sounds a bit rough sort of like a misfire but its not missing
in a day it will probably be fine again but there is obviouly a problem and wont be happy until its sorted.
im thinking turbo blades sticking?
can anyone help me?
thaanks

[GTi_Red]

ive been looking online and see that the pcv valve can be a culprit can anyone shed any light on this?
theres a bit of oil around it which has to becoming from somwhere cant see any splits in pipes

[Dom_]

My PCV was causing a bad idle, no boost problems

Do any codes actually come up? Maybe do some logging to test the MAF

[GTi_Red]

i dont know yet im going to plug it in tomorrow but dont have vag com got snap on solus pro.. any ideas to why it cleared now has started agin about 3 weeks later?

[Dom_]

Could be worth a try, unplug the MAF and take it for a spin, see if there's any difference...they're pretty common for going bad anyways

[GTi_Red]

ive unplugged the maf and it ran rough how ever ive just found this..pcv valve- So what happens when this little bugger goes wrong? well symptoms include the following

-A drop in boost with some people claiming 2-3psi
-A decrease in MPG
-Oil found in or around the diverter valve, oil cap, valve cover, engine cover and I've hear coil packs.

Now, you might have some of those symptoms or all of them which means quite probably you have a PCV valve failure. The diagnosis for a failed PCV valve is simple, there are two ways. The first is to remove the oil cap or the dip stick for a very brief moment as you don't want to screw up the pressure. If the engine retains its ideal as normal then you have a failed PCV valve (or so the saying goes) but if your engine suddenly runs rough and splutters a little then everything sounds gravy baby. remember you only want to do this briefly, not sit there with a brew saying "oh just one more minute we'll see if it starts to smooth out" mad The other way is to check by actually removing the PCV valve and blowing through it on the intake manifold side, if air goes through it without any resistance then your valve sounds dead. Or you could take the hose off intake manifold side to the pcv valve and blow through that.

my car idle didnt change when i removed the oil cap

[gti-joe]

Replaced mine last year as had the same oil residue on the pipes that went into it and was having limp mode issues etc. Once replaced have never had any more problems with my car, not saying that it will fix your problem but fixed similar problems I had.

When googling about the valve, found alot of the guys on the Vortex forum and a number of American Audi forums replace it as a matter of course every 1 to 2 years, by the sounds of it they are of a similar quality to the factory plastic dump valve that is fitted to the 1.8T and just give up and fail after a while.

Will probably replace mine every couple of years as they are not expensive.

Part number for the valve is: 034129101 B

[Simon90]

Are you running any kind of remap..?

When I had my first polo, I got it mapped a week later it went into limp or lack of boost, took it to the garage the recirc valve had failed so replaced it with 007p and problem solved..

Just my past experience?

[GTi_Red]

yeah it was done by superchips in 2008 and and its not the recirc as ive had it off and its free and i can here the 'dump' from it
thanks though

[GTi_Red]

Replaced mine last year as had the same oil residue on the pipes that went into it and was having limp mode issues etc. Once replaced have never had any more problems with my car, not saying that it will fix your problem but fixed similar problems I had.

When googling about the valve, found alot of the guys on the Vortex forum and a number of American Audi forums replace it as a matter of course every 1 to 2 years, by the sounds of it they are of a similar quality to the factory plastic dump valve that is fitted to the 1.8T and just give up and fail after a while.

Will probably replace mine every couple of years as they are not expensive.

Part number for the valve is: 034129101 B

cheers i hope im on to something with this!

[GTi_Red]

Got the code 17705 (p1297) pressure drop between turbo and throttle valve (check d.v) I have ordered a Pcv valve so see how that goes!

[Harney]

Ive been having the same problem!
Every now and then it wont boost any higher than 5psi. Engine off, back on, fine for a while.
Ive changed the PCV on mine as I had the same oily residue and must of done the same research but it still does it every now and then.
Im convinced there is a little hesitation upon acceleration which is then followed by this "soft limp mode" almost like a misfire so im thinking I'll replace the coils and plugs and see if that cures.

[Lowthy1989]

I said this before but manifold bolts coming loose are common! Sounds like your problem, exactly the same as mine

[GTi_Red]

what maifold? exhaust?

[GTi_Red]

actually that was dull haha