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Discussion Starter · #1 ·
Another month, another problem. :D

So my 1.8T 2000 New Beetle threw the P0411 Sec.Air Inj.Sys. Incorrect Flow Detected code about two weeks ago for the first time.

One of the hoses that goes from the top of the Secondary Air Pump to the Air Filter Box was sorta loose so I pushed it in all the way and cleared the code, stayed off for two weeks. Then last night the code came back on again.

I'm pretty sure my Secondary Air Pump needs to be replaced (my car has almost 150,000 miles on it) so I was thinking about starting there.

Another thing I've noticed recently was that my car is louder than it used to be. Has more of a growl to it than it used to.. almost as if it has a not so great aftermarket exhaust slapped on it, heh. This noise started randomly a week or two before the P0411 code tripped. Is there anything in the secondary air injection system that could cause the engine to increase in noise like that?

Looking into the rest of the system I see that there are the two large tubes that go from the air pump that should probably be replaced as well due to their age. After that it's the combination valve and diverter valve that make up the rest of that system, correct?

Any recommendations? I'm kind of considering on biting the bullet and replacing all three parts (plus the hoses) to see if it makes any difference.

The car does feel like it's not boosting as much as it used to as the Turbo is a lot less audible too..

Thanks again for any insight anyone might have! :D
 

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air pump

Replace the pump. You can get them off ebay at a good price(100). Sometimes it's just the 3 rubber bumpers that hold the pump in place that go bad, they crack/rut and the pump hits the bracket metal frame and makes noise. Or the pump itself is bad or a combination of both. You can get the rubber bumpers off ebay too and since they are old you might as well replace. The hoses get hair line cracks so you need to check those out really close. There is an FYI thread around here on how to repair the pumps that have the rivets but if your's don't have rivets like mine was you're SOL. Clean the cambi valve too if it has never been done, then use a hand vacuum pump and cycle it to make sure it opens and closes. good luck men...:p
 

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Replace the pump. You can get them off ebay at a good price(100). Sometimes it's just the 3 rubber bumpers that hold the pump in place that go bad, they crack/rut and the pump hits the bracket metal frame and makes noise. Or the pump itself is bad or a combination of both. You can get the rubber bumpers off ebay too and since they are old you might as well replace. The hoses get hair line cracks so you need to check those out really close. There is an FYI thread around here on how to repair the pumps that have the rivets but if your's don't have rivets like mine was you're SOL. Clean the cambi valve too if it has never been done, then use a hand vacuum pump and cycle it to make sure it opens and closes. good luck men...:p
I took a look around mine. Looks like new hoses and the rubber mounts are all but gone. Someone tried repairing it with a couple zip ties around the deteriorating mounts. I'm going to replace those mounts and see if the pump has any leaks. I can't imagine fixing those mounts will make the pump whine quieter though.
 

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hoses too

replaced the hoses too if they're bridle. Also remember that the cambi valve could be getting stuck and the pump is trying to force air through it. At a minimum I would clean the valve, replace both hoses and the pump supports. You can also remove the pump and physical apply 12vdc directly from the battery and see what type of noise or results you get. good luck man.
 

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I disconnected the hoses and ran the pump. It was as loud as ever. I'm convinced that its just a loud pump, but its still working which explains why I have no error codes. I'm trying to source a quieter replacement that doesn't break the bank.

I discovered my pump is the type that has no rivets, so there is no way to repair my pump as many others have.

UPDATE:

Just bought a replacement pump from a friend of a friend for about $20. I tested it out and it is MUCH quieter. Can't wait to install it! I highly recommend anyone with a loud pump to buy a replacement asap. They are super cheap from the junkyard and tons of them on ebay for around $40 shipped.

UPDATE 2:

I got the new pump in today and its SILENT! My pump came out of an R32 but its the exact same. Anarki, your problem doesn't sound like it was caused by a defective pump (but the pump could be damaged now), maybe a combi valve that is stuck open could cause these issues?
 

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The two times I've had the P0411 light come on, it had nothing to do with the secondary air system. It turned out to be a vacuum leak, both times involving the boost diverter valve. The first time was about 5 years ago, and the vacuum hose to the boost diverter valve was cracked, so replacing all the vacuum hoses fixed the P0411. Recently, I got the P0411 code again and checked the vacuum hoses for cracks. Everything looked good, so I bought a hand vacuum pump and started checking for leaks. It turned out the boost diverter valve itself didn't hold a vacuum. So replaced the boost diverter valve, and all the vacuum hoses again for good measure. Before the CEL light went on, I did notice that the fuel economy was lower than expected. After replacing the diverter valve, fuel economy is slightly (~5%) better, and no more CEL. (Knock on wood).

Off topic, probably something else is worn out in the emission system, because fuel economy is still not what I expect. I'm suspecting the PCV, because I also have been having oil leaks, and the PCV area looks wet. When I save up some money, will try to replace the hoses & stuff related to the PCV. My car is a 2000 1.8t, so the plastic & rubber stuff in the engine compartment is starting to deteriorate. Just had to replace the cooling flange for a coolant leak, and it looks like the evaporative emission control hoses and fuel injection hoses need replacing, as they are starting to show cracks & drying out.
 

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Discussion Starter · #8 ·
Ordered a bunch of parts since all the originals on my car are nearing 150,000 miles and 15 years of use, so if they're not already bad they'll be needing replacement soon anyhow.

Secondary Air Injection Pump (http://www.ecstuning.com/ES1844013/)
Pressure Control Valve (PCV) (034129101B - Pressure Control Valve (PCV) - ES#261091)
Combi Valve (Shut-Off Valve) (06A131102F - Shut-Off Valve - ES#4985)
Adapter For Combi Valve (058131817 - Adapter For Combi Valve - ES#4829)
Valve Adapter Gasket (078131120M - EGR Valve Adapter Gasket - Priced Each - ES#4828)
Connecting Pipe (06A131372 - Connecting Pipe - ES#279378)
Air Pump Intake Hose (1C0131126 - Air Pump Intake Hose - ES#297442)
710N Diverter Valve (06A145710N - 710N Diverter Valve - Priced Each - ES#2639822)

I replaced the vacuum hoses last year and they're still good so I assume slamming all those new parts in will make a difference for sure..

If it doesn't stop the P0411 from popping up at random then I'll be mighty peeved.

I shall update once the parts arrive and I get 'em installed!
 

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Discussion Starter · #10 ·
Well, all the parts have been installed (except the Combi/EGR Valve but I'll get to that in a moment) and it turns out my Diverter Valve was the cause of most of this.. the old valve was definitely faulty.

New 710N Diverter Valve has brought back the boost! :D

All the other stuff was still good to replace, new secondary air pump is running perfectly at cold start with no surging issues and all the tubes are nice and snug. The old ones were so brittle that pulling them off resulted in plastic cracking all over the place. Turns out the OEM Combi/EGR Valve was still good on my car so I ended up keeping that. ECS Tuning sent me a valve that technically doesn't fit the New Beetle due to hose placement.. seems to be for the Jetta or Passat but I'll be getting that refunded. Thankfully my old one was still good.
 
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