I have had ongoing problem with my 2001 Octavia vrs for a few years now. The problem is its very intermittent and difficult to describe the fault to a mechanic. It started with the car surging around 1000-2000 rpm (at first a this was my first turbo I put it down to turbo lag) the engine management like them came on, fault code 17705.

I had the throttle body cleaned which seemed to help for a period, but after a while the fault reoccurred. I then had the MAF replaced, again after a while the problem reoccurred. Recently I had 2 coils pack up in the space of 2 weeks, the car drove fine for a couple of days then started to run rough on idle, we then discovered I had a split breather hose and the pipe coming off it was also split. Having replaced all these and hoping the problem was cured I then discovered if I drove the car from cold it was as if it wanted to stall, there is no power until the revs drop to its normal idle.

After searching for answers I now leave the car running for about 1 min (until the revs drop) and it drives fine, until I drive the car hard, after driving it faster than normal I experience idle all over the place, as if it wants to stall, loss of power in low revs. I've had the car now for 6 years, regularly serviced, 65k on the clock totally standard. I realise I could have a serious of faults but I believe there is an underlying fault can anyone shed any light on what it can be its driving me crazy!!!

Matt

You definately should wait before driving it hard. The minute or so you mention after when it starts is the secondary pump working. The variable valve system kicks in to increase the revs and the secondary air pump puts air into the exhaust manifold, these are both needed to warm up the cat. It should take about 90 seconds after which the revs drop and it's ok to pull away otherwise it will be really lumpy and may kangaroo.

As for the idle being all over the place when you've been driving it - possibly coolant temperature sensor? The revs at idle depend on how hot or cold it thinks the engine is and if you have one of the following it may throw that out:

- faulty coolant temp sensor

- faulty thermostat (mine was faulty and meant if I switched off after going for a drive then switched back on again a little while later the idle revs would be all over the place)

- air lock in the cooling system

- faulty water pump

A fault scan should show a 17704 fault if it's one of the first two

Edited 4 April, 201016 yr by chicken_eyebrow

You definately should wait before driving it hard. The minute or so you mention after when it starts is the secondary pump working. The variable valve system kicks in to increase the revs and the secondary air pump puts air into the exhaust manifold, these are both needed to warm up the cat. It should take about 90 seconds after which the revs drop and it's ok to pull away otherwise it will be really lumpy and may kangaroo.

As for the idle being all over the place when you've been driving it - possibly coolant temperature sensor? The revs at idle depend on how hot or cold it thinks the engine is and if you have one of the following it may throw that out:

- faulty coolant temp sensor

- faulty thermostat (mine was faulty and meant if I switched off after going for a drive then switched back on again a little while later the idle revs would be all over the place)

- air lock in the cooling system

- faulty water pump

A fault scan should show a 17704 fault if it's one of the first two

Hi, when I drive it hard i mean after its warmed up, for example today i drove around 30miles, put my footdown to overtake, got to the next roundabout and as i pulled out i had no power at all (almost causing an accident as i couldn't keep up with the flow of traffic on the roundabout!! )

Are you getting an engine light or fault codes?

If the power is down that much it suggests its going into limp mode but you would normally get a light and/or fault code with that

is the asr light coming on ??? i.e are you giving it beans in first and losing traction as this will close the throttle and you will have no power.

Are you getting an engine light or fault codes?

If the power is down that much it suggests its going into limp mode but you would normally get a light and/or fault code with that

The ecu light is on, usually reports pressure drop 17705.

The asr light doesn't come on, unless it needs to.

As i had 2 hoses split, i might check all hoses and get the thermosat looked at.

Are you getting an engine light or fault codes?

If the power is down that much it suggests its going into limp mode but you would normally get a light and/or fault code with that

I have also noticed that when the car is playing up, I put the clutch down to stop at traffic lights for example, the revs will drop very slowly and sit at about 1000rpm's until i'm stationary, then they will drp to normal idle!

Has anyone had this symptom?

If you've replaced pipes in the past did you get the fault code cleared then? They need to be cleared after a fix is done or the ECU still thinks somethings wrong. My suggestion would be to clear the code, then see if that fixes it and if it comes back, if so then start checking the usual pipes for splits and leaks

Sounds like it could be a vacuum leak to me. I had similar problems a while back when I had a bad vac leak, but fixed it as soon as it happened and since then my idle is as solid as a solid thing!

My symptoms were an irratic idle speed, and sometimes the idle speed would just wonder off by itself as if it had plans of it's own to drive the car!!

Have a rumage under the inlet manifold....

Mine had EXACTLY the same problem as yours! Found out had broken/missing rivets on the secondary air pump, split hoses to the pump, gunged up throttle body & split breather hose on top right of cylinder head cover. With these sorted car has been running like a peach for the last 8 months.

Did you fully clean both sides of the throttle body? Also sometimes the intercooler gets a lot of oil in it that may get drawn up onto the throttle body and cause rough running so it might be an idea to look at that?

Mine had EXACTLY the same problem as yours! Found out had broken/missing rivets on the secondary air pump, split hoses to the pump, gunged up throttle body & split breather hose on top right of cylinder head cover. With these sorted car has been running like a peach for the last 8 months.

Did you fully clean both sides of the throttle body? Also sometimes the intercooler gets a lot of oil in it that may get drawn up onto the throttle body and cause rough running so it might be an idea to look at that?

Will have a look at that for sure, cheers

I have had ongoing problem with my 2001 Octavia vrs for a few years now. The problem is its very intermittent and difficult to describe the fault to a mechanic. It started with the car surging around 1000-2000 rpm (at first a this was my first turbo I put it down to turbo lag) the engine management like them came on, fault code 17705.

I had the throttle body cleaned which seemed to help for a period, but after a while the fault reoccurred. I then had the MAF replaced, again after a while the problem reoccurred. Recently I had 2 coils pack up in the space of 2 weeks, the car drove fine for a couple of days then started to run rough on idle, we then discovered I had a split breather hose and the pipe coming off it was also split. Having replaced all these and hoping the problem was cured I then discovered if I drove the car from cold it was as if it wanted to stall, there is no power until the revs drop to its normal idle.

After searching for answers I now leave the car running for about 1 min (until the revs drop) and it drives fine, until I drive the car hard, after driving it faster than normal I experience idle all over the place, as if it wants to stall, loss of power in low revs. I've had the car now for 6 years, regularly serviced, 65k on the clock totally standard. I realise I could have a serious of faults but I believe there is an underlying fault can anyone shed any light on what it can be its driving me crazy!!!

Matt

Did you manage to resolve this problem?

I've got the same issue.

Cheers

Did you manage to resolve this problem?

I've got the same issue.

Cheers

sorry for the very very very late response, i've just signed back on after months away!

But yes the problem has been resolved, I had the throttle body cleaned out.

My mate who cleaned it didn't think it would cause a problem because the throttle body wasn't very dirty, but the car has never driven better....................... at last!!!!! No more warning lights.

Matt