Hi all,

So far you guys have helped me sort a couple of big issues on my octavia, and now I hope you can put me on the right track with another:

W plate Octavia estate 1.9TDi SLI

122,000 miles on clock

At present it is getting to 2500-2750 revs in 5th and then the power drops off, and from then on it can't pull the skin of a rice pudding.

Now it was doing this in 4th as well, around 3,000 revs. Having read the forum for help, it was pointing towards the MAF, N75, Air filter or turbo pipework (I think mine is the 110, so may not suffer from the sticky vances issue). Now the garage has checked the pipework and changed the MAF for me, but it is still doing it in 5th gear. Revs and goes like a good un upto the 5th gear problem, 4k revs in 3rd and 4th with loads of power.

So now to my question: Would I be on the right track to change the n75 solonoid (I thinks its a solonoid) as the next possible solution, or is there anything else I need to have a look at first. If it was pointing to sticky vanes on the turbo then could I try to remotely clean them up with either the "italian tune up" or carb cleaner down the pipe, or is it a take it apart jobby.

it is a lovely car and a right workhorse, so hopefully this niggle can be sorted.

So far you guys have helped me fix an ABS issue (showed pump failure, turned out to be dirty fuse on top of battery) and the clocks issue where all the clocks die (thank goodness for idiot guide with great pictures and a works soldering iron)

Cheers

Simon

Simon

Once the car has started to go slow does it remain slow until you have cycled the ignition? (when you become skilled you can do this on the move - just don't take the key out or the steering lock will come on!)

The 110 has vanes - I should know as I have one Plus I have some odd turbo issues as well :'( As I have a couple of threads running about it at the moment.

Quite possibly someone with vagcom could either check for fault codes, or even do some logs..... where in the UK are you based?

Once the car has started to go slow does it remain slow until you have cycled the ignition? (when you become skilled you can do this on the move - just don't take the key out or the steering lock will come on!)

The 110 has vanes - I should know as I have one Plus I have some odd turbo issues as well :'( As I have a couple of threads running about it at the moment.

Quite possibly someone with vagcom could either check for fault codes, or even do some logs..... where in the UK are you based?

Ok, update: Had the N75 changed (so now new n75 and MAF), and it is still doing it in overboost. With the foot to the floor in 5th and 2500 rpm it thedrops into limp mode and drives like a tractor, reset ignition and all is fine. With accelerator at 75% it will pull in 5th upto 3000 revs and then go flattish, again then put foot to floor for overboost and it drops off till reset ignition. Looking at changing the air sensor next to see if that helps. in 3rd and 4th it pulls liek mad, so I am assuming that the turbo is fine, as it accelerates as a good un right upto near redline, just have the problem in 5th gear.

I am located in New Forest, near Southampton. Garage has stuck diagnostics on there for me (local guys, very good, and no charge), but it just said turbo issues, and did not give me the code.

Simon

we should all form a club- the sticky vanes club?- :S

mines doing excatly the same thing- started about a week ago- getting worse by the day :'( really starting to wind me up now.

tried n75- the same. :(

checked all pipework- ok.

sealed vac pump outlet- the same :(

i might try a spare maf i have laying around, but im pretty sure the turbo is coming off for a strip down next week (weather allowing) - ive tried litres of diesel cleaner/italian tuneups/ heating oil.. nothing has made the slightest bit of difference :(

without a fault code or log file it is just guessing tho and could be anything at all.

I always test the actuation a mityvac before removing the turbo. If anyone ever wants a second (or first) opinion on the turbo sticking problem and are local enough I will have a look/test it for you in eve's at work.

I've even got a rig now to bolt the turbo's to while they are stripped and worked on

I am seeing lots and lots now that are tight on the control ring rather than sooty vanes and no amount of "snake oil" is going to fix that without a strip and scrape

my old leaon had the same symptoms, turned out to be sticking vanes. was fine until a bypass then in 5th would die and end up with no power till i switched it on and off, some say cleaning works and some say it doesnt

my old leaon had the same symptoms, turned out to be sticking vanes. was fine until a bypass then in 5th would die and end up with no power till i switched it on and off, some say cleaning works and some say it doesnt

if it is just soot build up then sometimes the stuff you can get to wash it out does work, most of the ones i'm seeing are now due to rust build up instead tho

without a fault code or log file it is just guessing tho and could be anything at all.

I always test the actuation a mityvac before removing the turbo. If anyone ever wants a second (or first) opinion on the turbo sticking problem and are local enough I will have a look/test it for you in eve's at work.

I've even got a rig now to bolt the turbo's to while they are stripped and worked on

I am seeing lots and lots now that are tight on the control ring rather than sooty vanes and no amount of "snake oil" is going to fix that without a strip and scrape

yeh- ive got a fault code reader- keeps coming up with the overboost fault code :'( trying to dig out my mityvac - what am i looking for?- just a smooth movement of the actuator as i increase vac and smooth return movement?- if it moves nice and smooth, am i wasting my time removing and cleaning the turbo? i cant for the life of me work out what else can be causing it :S

someone else mentioned the fault being rust build up on the inlet side/ control ring rather than carboned up vanes??

now to find my mityvac- moved it somewhere on my pre- christmas clean up :( havnt seen it since..

innotec turbo cleaner is widely recommended

innotec turbo cleaner is widely recommended

I've found that it can provide a temporary fix, but it doesn't really work as it doesn't clear all the hard carbon and rust.

see post #4 in http://briskoda.net/forums/topic/181961-turbo-cleaning/

Removing the turbo and cleaning it is the answer.

A common mistake is only cleaning the actuator ring and the plate with the vanes/butterfly levers.

The actuator ring can also stick on rust/carbon on the housing or on the inside of the guide rollers so both of the these need to be cleaned with a dremel and a brush.

yeh- ive got a fault code reader- keeps coming up with the overboost fault code :'( trying to dig out my mityvac - what am i looking for?- just a smooth movement of the actuator as i increase vac and smooth return movement?- if it moves nice and smooth, am i wasting my time removing and cleaning the turbo? i cant for the life of me work out what else can be causing it :S

someone else mentioned the fault being rust build up on the inlet side/ control ring rather than carboned up vanes??

now to find my mityvac- moved it somewhere on my pre- christmas clean up :( havnt seen it since..

yes looking for nice smoothe movement, no creaking noises!! and when you release the vacuum it should return fully, test that it does by putting pressure in via the mity,and see if it pushes it home more than the return spring has.

test it stone cold AND when it is warmish and then hot as the control ring is stainless so expands much more and faster than the cast iron casing so can be owrse at different temps. quite a few of them will do it in the first mile then be fine as it gets hotter and the casing expands to match the ring.

you can test it and just about see it from on top altho i watch it from underneath

yes looking for nice smoothe movement, no creaking noises!! and when you release the vacuum it should return fully, test that it does by putting pressure in via the mity,and see if it pushes it home more than the return spring has.

test it stone cold AND when it is warmish and then hot as the control ring is stainless so expands much more and faster than the cast iron casing so can be owrse at different temps. quite a few of them will do it in the first mile then be fine as it gets hotter and the casing expands to match the ring.

you can test it and just about see it from on top altho i watch it from underneath

ok- ive just put the mittyvac on- creaking like hell- is this bad?- very hard to judge if its smooth movement- as each pump stroke seems smooth, but then you get to the end of the pump stroke and have to do another- it seems to require a huge amount of vacuum to get full travel - my vac gauge is knackered- so im not too sure of the actual vac value- but four fulll strokes, seems a large amount- very creaky tho :S ???

creaky is bad most likely the ring sticking but as its coming apart clean everything

when i get round to stripping this turbo and cleaning it, is it worth copper greasing all the internal moving parts? or is this likely to attract crud and just block it up quicker??

any thoughts? :S

no dont use any grease as it will burn up and leave deposits inside and make it worse, even copper grease will burn off, I did try it once and ended up stripping again 1 month later