1.8t Octavia VRS 2003

Seen a few posts on here over the weeks regarding this issue.... until its started happening to my car (or so i think)

every now and again ill give it some beans ... and it maintains power till about 3k-3.5k revs then the whole power seems to drop for no more than half a second then its fully back on. (happened in numerous gears)

doesnt happen often but its a noticable... huh what happened there.

have currently got an engine management light that keeps coming on... Engine running too lean and that the idle RPM is higher than expected.

Varying idle revs by a couple of 100 or so.

Is this seem in boost/power drop possibly an ACTUAL issue, or am i being paranoid? could the 2 be related (EML and the seeming power loss)?

Thanks for any help in advance, doing fancy things with your car is fine but at the end of the day i prioritise my engines well being above anything else

have you done a full scan?

I get ever so slight flat spots every now and again. I sometimes wonder if it sparking properly/coilpacks.

Does it sound like it is running rough?

I did a full engine fault code scan.

This is a rather noticable flat spot... i cant find any positive pipe leaks anywhere, (new set of spark plugs about 2 months ago btw)

im still toying with the idea of changing the MAF sensor, but £60 on a part that may not to be changed...

only other solution i think is Silicone hose replacements for the whole intake system and a MAF

Edited 1 June, 201115 yr by Milkybadger

Unplug the MAF & see if you still have the flat spot. If there's no difference then the MAF is ok.

Could be a sticky N75. They get slow to react, and you will get a slight overboost, followed by underboost for a split second.

Usually does it over and over again.

Deffo worth getting that problem sorted, you dont want to ever be running lean and hot.

have you cleaned the throttle body? This can cause all sorts of issues and flat spots. Only costs a couple of £ if you haven't. Did you get any fault codes when you scanned the car?

Could be a sticky N75. They get slow to react, and you will get a slight overboost, followed by underboost for a split second.

Usually does it over and over again.

Whats the N75, forgive my ignorance

Boost valve? where is it?

Thanks for the large amount of input, i think i need to get this sorted pronto.

Ill take my throttle body off at work today and give it a good clean, as by the looks of the previous owner who didnt know what an EML it will do it the world of good

have currently got an engine management light that keeps coming on... Engine running too lean and that the idle RPM is higher than expected.

Varying idle revs by a couple of 100 or so.

Is this seem in boost/power drop possibly an ACTUAL issue, or am i being paranoid? could the 2 be related (EML and the seeming power loss)?

Thanks for any help in advance, doing fancy things with your car is fine but at the end of the day i prioritise my engines well being above anything else

From that description it's fairly obvious that you have a bad vacuum leak.

So no need to go burning cash on things you don't need like new MAF's and N75's.

I'd guess that it's one of the breather hoses under the inlet manifold. An easy way to find the hose is to let the engine idle, and then poke about under the manifold. If you hear the engine note change, or hear a leak when poking a hose, then you know where the leak is.

For peace of mind you can just replace the entire breather system. It's not hard to do, just fiddly, and there should be some pics floating about from when I changed mine (twice!).

When I first had a catch can I had a bad vacuum leak, which kicked up the same error codes that you have. I've since moved away from using a can.

Follow the pipe from the airbox into the engine. The N75 is stuck in the top of it is a valve with 2 pipes attached to it (as well as the airbox pipe and a plug).

It's the valve which controls when the turbo wastegate opens. Is the car remapped at all?

Follow the pipe from the airbox into the engine. The N75 is stuck in the top of it is a valve with 2 pipes attached to it (as well as the airbox pipe and a plug).

It's the valve which controls when the turbo wastegate opens. Is the car remapped at all?

Nope ... ive got one of them Forge Recirc R valves btw which you adjust, got the values from forge themselves.

From that description it's fairly obvious that you have a bad vacuum leak.

So no need to go burning cash on things you don't need like new MAF's and N75's.

I'd guess that it's one of the breather hoses under the inlet manifold. An easy way to find the hose is to let the engine idle, and then poke about under the manifold. If you hear the engine note change, or hear a leak when poking a hose, then you know where the leak is.

For peace of mind you can just replace the entire breather system. It's not hard to do, just fiddly, and there should be some pics floating about from when I changed mine (twice!).

When I first had a catch can I had a bad vacuum leak, which kicked up the same error codes that you have. I've since moved away from using a can.

Smashing lol ... not a totally simple fix.... im trying to get hold of one of them smoke machines from work that you feed in behind your maf to find leaks but doubt ill get hold of it by the weekend.

how serious a problem do you feel this?, is it a &@$%£!" FIX IT QUICK BEFORE SOMETHING GOES BANG!? i expect im unknowignly loosing a fair bit of torque/power then if its a bad one.

Nope ... ive got one of them Forge Recirc R valves btw which you adjust, got the values from forge

Ah there might be the problem,take it off and fit either a standard recirc dump valve or a Forge 007 recirc v/v.

As mentioned before, you have a massive vacuum leak somewhere,unmetered air is coming into the system, I would bet on Y breather pipe or/and S pipe that connects it to check valve under the intake manifold. Also you should check measuring block 032 via vagcom, this will give you an idea what is going on....

Good luck!

As mentioned before, you have a massive vacuum leak somewhere,unmetered air is coming into the system, I would bet on Y breather pipe or/and S pipe that connects it to check valve under the intake manifold. Also you should check measuring block 032 via vagcom, this will give you an idea what is going on....

Good luck!

The Y crank case breather hose was obliterated but i replaced that a number of months ago. and the problem is still there.

Nope ... ive got one of them Forge Recirc R valves btw which you adjust, got the values from forge

Ah there might be the problem,take it off and fit either a standard recirc dump valve or a Forge 007 recirc v/v.

I dont understand how the Recirc R valve could be the problem could you elaborate on the principle behind this?

Dont get me wrong im gonna try the swap and see what happens, im just interested as into why

Ill take a look at the S pipe though and all aroudn that area this afternoon, hopefully turn up with something.

Second issue that arose today... may be related.. may not:

When i start the car from cold in the front passenger footwell i could hear like water being pushed through a pipe kind of sound, i assume this is the heater matrix going around and about somehwere... but recently its developed into a sort of knock, like somebodys tapping against the inside of the wheel arch. It goes after the cars warmed up, maybe ive got air in somehwere.

Edited 3 June, 201115 yr by Milkybadger

Second issue might be this one http://briskoda.net/forums/topic/187134-glovebox-clicking-v71-recirc-valve-fault/

try turning on and off recirc, see if that clicking goes away. have it on mine, but my solution is cheaper and easier - got some good music in my car and cranking the volume up while car is cold

ooo i found a cracked pipe,

Where the Y shape breather hose splits in 2... (the Y) one goes into the top of the head and the other goes down the battery side of the engine.

It connects to a black pipe, (it appears to be plastic and quite brittle)

Well the shield on the front of the engine with all the holes in and surrounds the oil dipstick, that goes up the side and fastens right by the pipe,

the bracket that that shield pops into is a hard foul against this black plastic pipe and appears to have cracked it quite badly..

Part number: 06A103213AF

Rang the local dealer today and,...... £34 .... bit expensive for a bit of plastic pipe

But i cant wait to get it on my car, finally get rid of that damned EML light and get my car running properly again,