Hi I am new to Skoda, having just purchased what I thought was an immaculate 2001 Octavia 1.9TDI Ambiente, I have just been for my first long run only to discover that I have a loss of power most noticably at 70 mph when attempting to overtake, the car didn't splutter or die completely just seemed to go backwards and the power faded, I couldn't get the car above 70 for the duration of the trip. I have a full service history and loads of invoices showing a replacement turbo only 18k ago so I am praying this is not to blame as I paid top dollar for the car, it looks and drives like new otherwise, the fault seems to be intermittent as it went fine again this morning pulling steadily to 90mph,any advice greatfully received.

Regards spool

You should get the car scanned with VCDS to check for an overboost.

143K, thanks for the reply, just stripped the rear drums down after thinking they were a bit on the noisy side and the handbrake a little on the light side (totally inoperative) to discover a requirement for replacement shoes, cylinders and drums, previous owner suggested I was exagerrating about the extent of the problem, how the car passed an MOT on those brakes is totally beyond me, the MOT centre claim it was ok on the day. No problem though the bits are ordered and I am more worried about the potential engine problem, I will try the MAF first. Can anyone suggest a cost effective way of improving performance without breaking the bank or greatly reducing ecomomy?

VCDS?

Cheers, spool

VCDS?

Cheers, spool

Also known as VAG-COM. Have a look here

Can anyone suggest a cost effective way of improving performance without breaking the bank or greatly reducing ecomomy?

I assume it is the 110?

No its the 90, in retrospect I should have perhaps given more thought to this prior to purchased but I was seduced by the economy, which to be honest is going to be more beneficial 90% of the time it's just for away games when I've got 3/4 football players with their kit on board that I could do with a bit more overtaking oomph.

Regards spool

In reply to Spool

My Skoda is 1996 Diesel 154K and it had your problem(power/turbo dies at abouy 70 mph)I drove it for over 50Kmiles then I took off MAF sensor and washed it in Isopropyl(Halfords electircal cleaner) and the problem went away so I would say your MAF is knakered.I bought a lead and software off Ebay for £8.99 it lets you do the autoscan and comes up with faults,some of the it just gives you the fault code and you look them up on Ross Vag COM site.You can also delete fault codes.It also gives loads of realtime readings as the engine is running.I am about to change my MAF,from my previous owners service history it has already had 2 new MAF's.

A 90 will remap to make more power and torque than a standard 110 with no loss of economy.

Thanks for the replies chaps, much appreciated, I will try a clean up with IPA first and see if it helps.

With regard to the remap can you advise on approximate cost and is it something the main agent would do or is it an independent specialist job, if it's an independent can you recommend anyone in the Carlisle/Dumfries area?

Thanks again, spool.

I've heard of a few Skoda dealers doing it, but it's usually an independant specialist job.

Ho Ho Ho Xmas Comes early to some

Took delivery Thursday of my new MAF sensor off Ebay £30 inc delivery.

Deleted fault code using VAG COM fitted MAF(10 min job)Started up,very smooth took it for a run and turbo works!Car went great loads of power! No sticky vanes(as 1st thought)Who can believe a duff MAFF would stop the turbo working(not me).Went for a run on M5 and the turbo did "cut out" at about 70mph as it used to before the problem in this listing/thread.Got home and plugged in VAG COM and got fault 17958 Charge pressure control deviation,which I think means overboost on turbo/leaky vacum somewhere.Will check for vacuum leaks.

Anyway MAF has solved main turbo not working problem!

I did read on the net that VAG COM can cycle the turbo vanes to see if they are sticking?

Spool your problem sounds like my current problem power loss at about 70mph under load,try a VAG COM check and see if it gives the 17958 fault?

I have noticed that the new MAF has a diode fitted to sensor and the old MAF has the fittings but no diode?(orange component that looks like a transparent resistor?

No its the 90

iirc, most of the 90s don't have VNT based turbos. If you post your engine code, then I am sure that someone else can confirm this.

Ho Ho Ho Xmas Comes early to some

Took delivery Thursday of my new MAF sensor off Ebay £30 inc delivery.

Deleted fault code using VAG COM fitted MAF(10 min job)Started up,very smooth took it for a run and turbo works!Car went great loads of power! No sticky vanes(as 1st thought)Who can believe a duff MAFF would stop the turbo working(not me).Went for a run on M5 and the turbo did "cut out" at about 70mph as it used to before the problem in this listing/thread.Got home and plugged in VAG COM and got fault 17958 Charge pressure control deviation,which I think means overboost on turbo/leaky vacum somewhere.Will check for vacuum leaks.

Anyway MAF has solved main turbo not working problem!

I did read on the net that VAG COM can cycle the turbo vanes to see if they are sticking?

Spool your problem sounds like my current problem power loss at about 70mph under load,try a VAG COM check and see if it gives the 17958 fault?

keep trying to add my final result to my original listing but it keeps going to another problem?

Ho Ho Ho Xmas Comes early to some

Took delivery Thursday of my new MAF sensor off Ebay £30 inc delivery.

Deleted fault code using VAG COM fitted MAF(10 min job)Started up,very smooth took it for a run and turbo works!Car went great loads of power! No sticky vanes(as 1st thought)Who can believe a duff MAFF would stop the turbo working(not me).Went for a run on M5 and the turbo did "cut out" at about 70mph as it used to before the problem in this listing/thread.Got home and plugged in VAG COM and got fault 17958 Charge pressure control deviation,which I think means overboost on turbo/leaky vacum somewhere.Will check for vacuum leaks.

Anyway MAF has solved main turbo not working problem!

I did read on the net that VAG COM can cycle the turbo vanes to see if they are sticking?

Spool your problem sounds like my current problem power loss at about 70mph under load,try a VAG COM check and see if it gives the 17958 fault?

Ho Ho Ho Xmas Comes early to some

Took delivery Thursday of my new MAF sensor off Ebay £30 inc delivery.

Deleted fault code using VAG COM fitted MAF(10 min job)Started up,very smooth took it for a run and turbo works!Car went great loads of power! No sticky vanes(as 1st thought)Who can believe a duff MAFF would stop the turbo working(not me).Went for a run on M5 and the turbo did "cut out" at about 70mph as it used to before the problem in this listing/thread.Got home and plugged in VAG COM and got fault 17958 Charge pressure control deviation,which I think means overboost on turbo/leaky vacum somewhere.Will check for vacuum leaks.

Anyway MAF has solved main turbo not working problem!

I did read on the net that VAG COM can cycle the turbo vanes to see if they are sticking?

Spool your problem sounds like my current problem power loss at about 70mph under load,try a VAG COM check and see if it gives the 17958 fault?

Hi Simon, I have a vagcom diagnosis and got the 17965 code N75 fault, I put the car up and after removing the sump cover I checked the operation of the VNT pneumatic actuator whilst revving the engine to 4000rpm, previously it cut out at 2500, I also replaced the dodgy looking hose going into the bottom of the actuator, I also manually actuated the vane rod (quite difficult to get access whilst in situ), to add to this I have put an addative into the last tankfull, the car has improved dramatically revving and pulling freely upto 4000rpm(under load) the fault is now only coming on at 4250 so things are definitely improving, I am hoping that by the time the tank is empty and I have run the car hard a few more times my problems will be behind me. I spoke to a Tech from the local Skoda garage who is sure the rod/vanes on the turbo are sticking but as it is only 6 months since the last turbo recon I am hoping this is not the reason in this case and that a bit of use will free things up and blow the cobwebs out as the previous owners would rarely have gone above 2500rpm under any circumstances. Best of luck with yours.

Regards Stewart.

Latest update after 10K Spray:-

Drove car this morning and car drives like a car with no turbo,it just goes normally and no rattling if I put my foot down.If I keep trying to "boot it"the turbo eventually starts working and it goes great.So it looks 99% like the vanes sticking?

The sticky vanes works the other way usually.

Boot it you get boost, then it sticks open, you get an overboost error logged and the car goes into limp home. This is reset by a stop/restart the car cycle.

I'd actually look at putting a new genuine MAF in there as to be fair past 60k they tend to suffer a bit.

Also check your N75 valve if you have not already and the other things mentioned above.

If you can put a tank bottle of redex in a quarter tank of fuel and give it an itallian tune up that might help if the turbo is sticking as I can see you've updated the thread from where I replied.

I have only ever once had a warning light on my dash once, even though I have had loads of limp home modes.

I suspect your turbo is getting stuck in a number of places, thus providing too much boast (and the limp home) and sometimes stuck in a wide open mode (producing minimum boast, unless high up the revs)

I forgot to add a new MAF sorted everything and car has run great till July 2011 and I have a similar problem after even after fitting recon diesel pump.Lacks power but unplugg MAF and it goes really well,bought new MAF but still runs terrible with it connected,runs good with it unplugged?Lost for words.

I forgot to add a new MAF sorted everything and car has run great till July 2011 and I have a similar problem after even after fitting recon diesel pump.Lacks power but unplugg MAF and it goes really well,bought new MAF but still runs terrible with it connected,runs good with it unplugged?Lost for words.

Could be a faulty MAF. Can you borrow one from a known working car? Unplugging the MAF alone suggests to me that it (or the wiring) is faulty.

Have you scanned with VAGCOM for what the MAF is reporting, and also for any ECU logged faults?

I am 3 years older and wiser.My car has a over boost valve not variable vanes so there was never an issue with sticky vanes,it's easy to tell if you have a variable vane turbo the actuator arm runs parallel to the turbo to open the vanes and the turbo with boost valve the arm run at right angles to the turbo so it opens the valve if too much boost.There are photos of each online and on one of my other listings for loss of power.

It is now May 2023 and I have solved my original problem...lack of power ....injectors cleaned and tested £50 still no power,recon diesel pump bargain off ebay £140 fitting £150 still no power new turbo off ebay £150 bargain fitting £50 and still no power and garage I think felt sorry for me hence £50...eventually sold car to Poland for £180....Good bye....Bought identical Octavia 1999 1.9tdi Y Reg 96k miles ran great loads of power even after converting to veg oil kit...Changed timming belt and lost loads of power?vcds timming checked out etc etc ...car got slower and slower?same as scrapped car?Took off egr unit and 90% clogged with soot only small air hole through middle so no wonder no power.Car ran better next day but now and again loss of power and chattering from engine?Been out tonight and found plastic pipe not secured to intercooler with spring clip(not put on properly when I changed timming belt)Put clip on securley and car goes like a rocket.....super fast...so I am 100% sure this was the problem with previous car egr exhaust inlet manifold badly sootedd(running veg oils helpd clogg quicker)will keep an eye one egr see how long it takes to soot up.

a catch can (or elephant mod) along with an EGR blank plate will keep the EGR /anti shudder assembly nice and clean. A few more years have added to my knowledge too!