I don't know if I have posted this in the right section but here goes. I have a Skoda Octavia 1.9 tdi 54 plate. The problem is that when I was driving I lost power and apparently the car went into "Limp Mode" took it to get diagnosed by a Skoda Dealer who said it was the Solanoid Valve so I got one and had it fitted, then they diagnosed the Air pressure valve which again I bought and had fitted, then they come away with it's the EGR valve which I bought and had it fitted, then they said it was the Air flow meter which I bought and had fitted. The car still loses power but no fault light comes on ie: engine management light. So I get into the car and start to drive then I lose power. If I stop and restart the car it usually clears and it's ok for the rest of the day. Today I started the car this moning and no power again, drove it about 3 miles, stopped the engine, waited about 5 mins, started the car and away it went. I'm getting a bit annoyed at paying "80 a throw for Skoda to tell me it's this and it's that so ANY help would be appreciated.

Thanks in advance.

Sounds like the vnt in the turbo needs cleaning very common issue!!!!! Sounds like you have been taken the poss out of !!!

Main dealers :thumbdown:

As above sticky VNT turbo.

http://www.audi-sport.net/vb/a4-s4-forum-b5-chassis/107121-un-sticking-your-tdi-vnt-turbo-vanes.html

If you have a laptop running windows get an ebay OBDII VAG cable (usually comes with VAGCOM 409.1) it'll save you a load of money.

Edited 22 January, 201214 yr by pauldazzle

BTW cycling the ignition should pull it out of limp. No need to wait 5 mins.

Why not see if there's someone near you with VCDS and get them to check? If it is the VNT it will log a code.

could be a split vacuum pipe aswell, mine was going into limp mode & it turned out to be a split vacuum pipe, it had been slightly rubbing on the power steering pipe & after 236000 miles it finally wore through enough to cause the limp mode, try & get any codes read when it does it next & post them on here, its far cheaper to get a code reader from ebay, it might not do all the fancy stuff but at least u can read the codes. i got one for about £45.00 & its payed for itself already,lee

Code readers don't recognise a lot of VAG DTC's so VCDS/VAGCOM shareware with an ebay cable is a better option. Cables normally go for about £15 with free software.

I would stay sticky vanes in the turbo.

To be far to the garage they are just doing what most Skoda dealers do - changing parts till it works.

- MAF

- N75

- MAP (optional)

- Turbo

is the route my local Skoda dealer said they would replace things, when I quizzed them about it.

In the case of my car the vanes weren't moving properly, but that was due to a split vacuum hose... Specifically the rigid hose to the brake servo.

You can become expert at cycling the ignition while you are moving. Although beware of the steering lock!

Thanks for all the replies. Some tech talk I didn't understand but I think I get the idea. I will take it to a local garage with the list of things you have suggested and see what they come up with. I take it that a VCDS/VAGCOM Shareware with cable is a diagnostic tool that I use with my laptop? Sorry but tech know how isn't my strong point. I need the idiots guide. I will keep you posted and if I do get a diagnostic tool then I will post the codes. Just as a matter of interest how much would it cost to have the vent in the turbo cleaned?

Thanks again.

Have a look at how Variable Vane Turbo work, so you understand what we are talking about. Essentially the n75 valve (on the bulkhead) applies a vacuum to an actuator on the turbo. This in turn moves a control rod which makes the vanes in the turbo move.

Here is a video

On some cars these get sooted up on the turbo side, but in most cases the control ring side gets rusty. Essentially the vanes jam, generate too much boost, the car detects it (via the MAP sensor) is getting more boost than it wants/expected and drops into limp mode to prevent damage.

Just seen a pikey cleaning method: http://www.audi-sport.net/vb/a4-s4-forum-b5-chassis/107121-un-sticking-your-tdi-vnt-turbo-vanes.html

However the best root is to take the turbo off, clean it and refit. Book time is about 3 hours + cleaning time. I did mine at home over the weekend. Generally you need a few new gaskets (3) and a new oil feed pipe to the turbo.

I would expect you will see an overboost fault code. VCDS/VAGCOM can operate in shareware mode with a cheapo ebay cable and will do basic stuff, like fault code scanning.

Edited 22 January, 201214 yr by mbames

Well a few days have passed and car STILL goes into limp mode. In and out of garages. No faults showing but the found a perished hose by the turbo and replaced it. Went ok for a day then back to limp mode. Now this usually happens first thing in the morning, then after a couple of restarts it's fine for the rest of the day. This is costing me a fortune in garages extortionate rates per hour. I really need some help here. Has anyone ever come across the same thing. As I said earlier I have replaced the EGR valve, the Air pressure valve and the Air flow meter and now the diagnostic shows "No Faults" and when they replaced the hose the turbo came up "OK" Please help. If I had any hair I would pull it out. Thanks again in advance.