Earlier this year, I had P1021 error to do with throttle valve. It was cleaned out by a garage, however, I'm not convince they cleaned out the EGR inlet manifold at the same time. Eitherway, the throttle valve EML error is back, I thought it might be coming as car rattles sometimes when switching off engine. 

 

Evidently, I'm going to have to have it cleaned again, and insist the mechanic clean the end of the EGR inlet manifold or get them to clean out the entire thing.

 

In the mean time, because opening times are bad between now and Jan 2nd, is it ok for me to drive the car in Sports Mode so that higher revs are held all the times, leading to what I hope will be higher exhaust temperatures running through the EGR valve / throttle valve? Also, should I avoid switching off the engine as much as possible to avoid the rattle when switching off (someone said it was the valve trying to "centralise"??").

Edited 28 December, 20196 yr by newskodadriver

The ECU won't instigate a regen while that fault code is present.

 

It's also very difficult to get a passive regen to take place, unless you can get a sustained high load on the engine at about peak torque revs, around 2000RPM.

Revving it will not help, that just sends more cooling air through the engine & DPF when you are trying to achieve a high temperature in the exhaust gas & DPF.

 

I would get a new throttle valve as your income depends on a reliable motor.

 

I have found that sometimes the throttle valve electronics, ( inside that black plastic cover on the side of the valve ) get submerged in black engine oil that is partially conductive.

The oil seems to run down from the discharging EGR, onto the throttle valve spindle, then along the spindle & into the electronics & electric motor shorting things out & stopping it working properly.

 

 

7 minutes ago, PipH said:

The ECU won't instigate a regen while that fault code is present.

 

It's also very difficult to get a passive regen to take place, unless you can get a sustained high load on the engine at about peak torque revs, around 2000RPM.

Revving it will not help, that just sends more cooling air through the engine & DPF when you are trying to achieve a high temperature in the exhaust gas & DPF.

 

I would get a new throttle valve as your income depends on a reliable motor.

 

I have found that sometimes the throttle valve electronics, ( inside that black plastic cover on the side of the valve ) get submerged in black engine oil that is partially conductive.

The oil seems to run down from the discharging EGR, onto the throttle valve spindle, then along the spindle & into the electronics & electric motor shorting things out & stopping it working properly.

 

 

the dealership mechanic earlier in the year thought if the throttle valve needed cleaning, then the egr valve wouldn't be too far behind. 

 

He also advised to just replace both throttle and eventually the EGR. Said the EGR clean was a 6 hour job but replace was 3, or something. 

 

However back then, and still now, I feel like cleaning could be a cost effective solution? I mean, the problem is essentially chimney soot, I just don't have any Victorian midgets to climb in with a brush 😞

 

Apparently, the throttle valve will "always look sooty", but if its not "wet with oil" then it won't have to be replaced? 

 

//

 

Also, when Im sitting in the car but engine not shut, will revving it to 2k rpm in neutral do anything either? Obviously I have a pick a spot that won't annoy residents

Edited 28 December, 20196 yr by newskodadriver

Depending on how the EGR might be cleaned, labour time won't be much different between cleaning and replacement. If cleaning it involves removing it, then replacement will be faster as there's no cleaning process to add on time. It's about 6 hours labour to remove/refit the EGR as a lot of stuff has to be removed for access. At that point, a new valve makes more sense to me as the part is not terribly expensive by comparison.

 

There's an official mod by VAG on the EGR port in the intake throttle which involves rotating it 180* from its original position. If you do a search around here you should find details on how to do it. It's supposed to be able to help stave off throttle valve clogging.

 

If the throttle was properly cleaned a few months ago, and it's getting clogged again this quickly, it points to the possibility of more serious problems with the engine, either generating too much soot or too much oil vapour getting into the intake.

3 hours ago, chimaera said:

Depending on how the EGR might be cleaned, labour time won't be much different between cleaning and replacement. If cleaning it involves removing it, then replacement will be faster as there's no cleaning process to add on time. It's about 6 hours labour to remove/refit the EGR as a lot of stuff has to be removed for access. At that point, a new valve makes more sense to me as the part is not terribly expensive by comparison.

 

There's an official mod by VAG on the EGR port in the intake throttle which involves rotating it 180* from its original position. If you do a search around here you should find details on how to do it. It's supposed to be able to help stave off throttle valve clogging.

 

If the throttle was properly cleaned a few months ago, and it's getting clogged again this quickly, it points to the possibility of more serious problems with the engine, either generating too much soot or too much oil vapour getting into the intake.

I've checked my post history, throttle valve body and valve was cleaned in May. 

 

However, I'm not sure if they cleaned the "egr intake valve / manifold" that other people have said were right next to the throttle valve. 

 

Is there a part of the EGR valve that you can clean after taking out the throttle valve without having to remove the entire EGR system?? 

 

Also, because I'm unsure right now what the problem is, and I don't think any garage is going to have time to fit / clean entire egr valve and/or throttle valve before New Year eve, would the best choice of action on Monday be to ask the indy garage to take out the throttle valve again to reclean and check condition and to scoop also as much from EGR as possible (where is this intake thing???) 

 

Would it be obvious if it's oil vapour causing this recent issue as opposed to soot? I assume if it is soot, it will be stuff blown in from a dirty EGR valve. 

 

//

Yeah I think I remeber reading something about a mod, but if you point it away from the throttle valve, where else in the engine is the soot going to end up? Could it be possibly worse?

 

Bit of a nightmare to have this happen before New Year's Eve. But thanks for everyone's advice so far. 

 

 

Edited 28 December, 20196 yr by newskodadriver

This thread shows how to do the modification and we veered off a bit into a technical discussion about what's happening.

 

 

22 minutes ago, chimaera said:

This thread shows how to do the modification and we veered off a bit into a technical discussion about what's happening.

 

 

 

 

Is that the egr intake pipe that people are saying that can be cleaned at the same time as the throttle valve? 

 

If you click my link it should take you to 1 minute 11 seconds into the video where the guy pulls out half of a pipe befoee taking out the throttle body. 

 

He also seems to do the job without much difficulty. 

 

If this is going to be a regular problem on my car. Should I try and learn to do it myself? 

21 hours ago, PipH said:

It's also very difficult to get a passive regen to take place, unless you can get a sustained high load on the engine at about peak torque revs, around 2000RPM.

 

I took it for 70 mile round trip mostly at 2k revs at end of a shift when engine etc was already warmed to operating spec. Reckon that did anything for the throttle valve? Or does it just not get hot enough. 

 

Engine light did not come on last nights shift, pretty confident about tonight's shift, worst come to worst, I should have a pretty passive regened DPF to push through and got a OBD2 to clear fault code if it appears again. 

Edited 29 December, 20196 yr by newskodadriver

12 hours ago, newskodadriver said:

 

 

Is that the egr intake pipe that people are saying that can be cleaned at the same time as the throttle valve? 

 

If you click my link it should take you to 1 minute 11 seconds into the video where the guy pulls out half of a pipe befoee taking out the throttle body. 

 

He also seems to do the job without much difficulty. 

 

If this is going to be a regular problem on my car. Should I try and learn to do it myself? 

That rubber pipe is part of the air intake to the engine, nothing to do with the EGR. The EGR pipe is the metal pipe that connects into the right hand side of the plastic plenum on top of the engine (just beyond the throttle body). If you read through the thread I linked to above, it discusses the issues with how that EGR flow is introduced to the engine, and why the mod to the orientation of the intake port is warranted.

 

If your car is running well, it's not a job that should need doing very often. I did mine earlier this year and it was still pretty clean after 140000 km. I don't expect to need to look at it again for a few years. It's not too hard a job to do, but disconnecting the flex pipe from the throttle body is a bit fiddly, and you'll need some torx driver bits for the three screws on the throttle body.

 

If your TB was cleaned a few months ago and the fault code has returned again, I see a few possibilities:

• It wasn't fully cleaned the last time and has gunked up enough again to throw the code
• It was cleaned but your car isn't running well and has gunked up again
• The fault has nothing to do with gunk accumulation: it may be that the actuator has failed/is failing, or that the wiring to it is damaged

I'd start by ensuring the TB is clean and that the butterfly can move freely both by hand, and when actuated using the Output Tests function in VCDS. If it's clean and you're still getting the code, then valve operation could be checked using Output Tests, but if it's intermittent you may not pick it up immediately. At that point you're probably looking at a replacement TB.

 

13 hours ago, newskodadriver said:

Would it be obvious if it's oil vapour causing this recent issue as opposed to soot? I assume if it is soot, it will be stuff blown in from a dirty EGR valve.

 

Yeah I think I remember reading something about a mod, but if you point it away from the throttle valve, where else in the engine is the soot going to end up? Could it be possibly worse?

The problem is caused by a combination of oil vapour and soot mixing and forming a mucky gunk that sticks to the intake pipes. Oil vapour comes from the crankcase ventilation system, and from the small amount of oil that inevitably gets out of the turbo shaft bearings. An increase in oil vapour would usually point to issues with wear in the turbo.

 

Soot is obviously coming back from the exhaust: the EGR flow is taken before the DPF so it will still have soot in it. Soot amounts would usually be quite low since the EGR only functions at part load. If soot formation is going up it's usually down to poor combustion: not enough air (turbo problems), too much fuel (injection system problems), or poor atomisation of fuel (worn injectors specifically). More soot in the intake air could also potentially increase soot formation since it could cause fuel droplets to merge/stick together after injection and lead to combustion problems.

 

The mod just changes the way the EGR flow is introduced to the air intake: there's no change in how much exhaust enters, just the direction it enters the flow at.

40 minutes ago, chimaera said:

If your TB was cleaned a few months ago and the fault code has returned again, I see a few possibilities:

• It wasn't fully cleaned the last time and has gunked up enough again to throw the code
• It was cleaned but your car isn't running well and has gunked up again
• The fault has nothing to do with gunk accumulation: it may be that the actuator has failed/is failing, or that the wiring to it is damaged

I'd start by ensuring the TB is clean and that the butterfly can move freely both by hand, and when actuated using the Output Tests function in VCDS. If it's clean and you're still getting the code, then valve operation could be checked using Output Tests, but if it's intermittent you may not pick it up immediately. At that point you're probably looking at a replacement TB.

 

 

is the butterfly the flap in the middle of the tube that whirrs as you push it close and it opens again?

 

Hmm, the generalist indy garage that does a lot of taxis/minicabs definitely do not have VCDS, I'm not sure "output tests" can be done on a general reader? 

 

I don't know how urgent this problem is because I need the car to run for new years eve / new years day, then I don't care if it's off the road for a bit cos I need a break. I drove 210 miles approx last night, 140 due to work and 70 for a high speed 2k rev runabout, no light, though still occasion judder as engine switches off. I have tonights shift to see if the light comes on again.

 

there is an indy skoda specialist nearish to me that isn't "too expensive", but their availability tends to be poor as they get good trade

Edited 29 December, 20196 yr by newskodadriver

2 hours ago, newskodadriver said:

is the butterfly the flap in the middle of the tube that whirrs as you push it close and it opens again?

Yes.

 

2 hours ago, newskodadriver said:

Hmm, the generalist indy garage that does a lot of taxis/minicabs definitely do not have VCDS, I'm not sure "output tests" can be done on a general reader?

It depends on the scan tool - there are tools other than VCDS that can do this too, but VCDS is the one I'm familiar with myself. If it's a cheapie OBD2 tool then definitely not.

 

2 hours ago, newskodadriver said:

I don't know how urgent this problem is because I need the car to run for new years eve / new years day, then I don't care if it's off the road for a bit cos I need a break.

If the code is cleared and not coming back you should be fine over the next few days.

On 29/12/2019 at 15:54, chimaera said:

Yes.

 

It depends on the scan tool - there are tools other than VCDS that can do this too, but VCDS is the one I'm familiar with myself. If it's a cheapie OBD2 tool then definitely not.

 

If the code is cleared and not coming back you should be fine over the next few days.

So.. I had it taken out and cleaned again about when you last posted, on the 29th December, just under a month ago. 

 

Even after clearned, sometimes the engine didn't shut off "smoothly", but the engine light only came back on tonight, after a couple of thousand miles. After clearing it, it keeps coming back.

 

P0121

 

When they took it out to clean last month, I was told that it "wasn't too bad", though it was obvious covered in sticky soot. When the mechanic used the screwdriver, the stuff he got off curled instead of dropping or shattering. That suggests it was at least a little wet. 

 

But it was all dry, then no soot would stick right? It would just blow right off. 

 

One thing I noticed was that the flap shut at an angle, it wasn't horizontal relative to the pipe, I don't know whether that was design or defect. 

 

No garage near me really has vcds, not even the small indy skoda specialist, never mind the general garage. When I asked the generalist indie mechanic to do an "actuator test", he drew a blank. 

 

I got my council taxi test next week. I dunno what to do now. If the engine light is on it would be instant fail, but there aren't other noticeable failure of engine component like turbo or EGR. 

 

I'm unsure whether buying a new throttle body is going to solve it? 

 

 

 

" One thing I noticed was that the flap shut at an angle, it wasn't horizontal relative to the pipe "

 

The flap should normally be perfectly in line with the air flow so it causes no obstruction.

 

It sounds as though the gears inside that drive the flap are probably damaged.

 

A new one isn't very costly & would have thought palls into insignificance against a days lost work as a taxi.

 

You can remove the plastic side cover from the valve to inspect the gears, drive motor & electronics.