Stuck EGR valve!

[nectarguru]

I've been dealing with a sticky EGR valve for about a year - Code P0401. The CEL would come on intermittently, which would usually go away after a day of heavy driving, putting the pedal to the floor and pushing good air. Eventually I started adding some LiquiMoly which seemed to stop the CEL from returning (about 3-4 months) until recently. The light has been on for a few weeks now even after adding a fresh bottle of LiquiMoly. Is it time to take it in for service, or are there any last ditch efforts I can try to get this valve unstuck?

 

[Lightflyer1]

Cracked dpf more than likely from my reading. Lots of posts on this code and usually associated with a cracked dpf leaking soot clogging the egr.

 

[nectarguru]

Been doing some reading up on the cracked DPF vs EGR, guess it could go either way. I'm also seeing a pretty wide range of prices for a cracked DPF repair. Seems like I could be safe driving the car for awhile until I get a proper diagnosis and decide on a solution?

 

[bashik]

Hello! if there is soot in the pipe at the back, it means the DPF is cracked. In this way, soot enters the EGR system and clogs it. Check the pipe at the back of the car with your finger.

 

[nectarguru]

Yep, definitely have soot in the back. I know this is an expensive fix but do you have any idea what I would be paying at a quality local shop versus the dealer?

 

[bashik]

The dealer billed me 1000 for the work, 1500 for the filter, plus various gaskets and a filter EGR
I cleaned the cooler and there are no errors, I have very little soot in the back. I removed the cooler and washed it inside.I understand that this is a temporary solution, but I’m not ready to pay that much money for a new filter right now. Moreover, in the discussions they write that in a year they change it two or three times for a new one under warranty

 

[Lightflyer1]

You need to check if you are in warranty or not for the dieselgate warranty. If so they should cover it.

VW Emissions Modification Lookup

www.vwdieselinfo.com

 

[oilhammer]

The OP has a 2015 Golf, that's a CRUA engine, and shares nothing with the CJAA. So the cracked DPF thing doesn't apply. It has something else going on.

 

[MrCypherr]

These ones have 2 EGR valves. One on the back side and one on the intake manifold. The testplan should tell you which one it is as it performs test for each. I've seen more and more of the valves on the intake manifold become faulty because the ports in the intake manifold become plugged with soot, Thus not allowing proper flow. Usually the fix is replace the valve and manifold. Now, if you arent under warranty, I guess you could try and clean the ports on the manifold to see if it will last and not through the fault. Although, the valve itself might be clogged and need replacing.

 

[oilhammer]

The CBEA, CJAA, and CKRA also have two EGR valves.

But yes, in the OP's case, need to do the self test for both the EGR motors, V338 and V339. At least narrow it down. Neither one is especially quick and easy to access, though.

 

[MrCypherr]

Thats true, I guess I worded that a little wrong. But yeah, the one at the back is a PITA to do. Manifold isnt too bad to take off on these. Even bleeding it is nice cause of the test-plan provided. The dealer should know pretty quickly by running the test which one it is.

 

[bashik]

But what about the fact that there is soot in the back of the pipe?I don't think a good DPF filter on this engine should allow soot through.

 

[nectarguru]

I'm not as tech savvy on my MK7 as I was with my MK4. Beyond blasting the engine with air by driving in 3rd on the freeway or dunking LiquiMoly in the tank, I'm looking at a shop repair. Trying to prepare my wallet with a range of costs....

 

[nectarguru]

Update! I added another bottle of LiquiMoly in the tank today, and wouldn't you know it, about a half hour later the CEL turned off. First time in several weeks! Would this rule out the cracked DPF, or could the additive possibly clean up the exhaust temporarily until it's used up, at which point the CEL will return? The car doesn't seem to be as smelly as it was prior to the CEL turning off.

 

[MrCypherr]

These ones dont have the cracked DPF issue the other CRs have. I dont think it would fix the issue cause the issue is the manifold itself where the ports are for the EGR valve off the manifold or the valve on the EGR cooler.

 

[nectarguru]

At this point would the problem be a broken or faulty part, or just a very dirty/sooty engine? This has been popping up for about a year now, and I figured that I've been milking the issue long enough to where a faulty part had finally failed. Very surprised that the light turned off this time.

 

[740GLE]

umm liquidmoly what to the tank? Used motor oil i hope , just kidding.

also stop leak has been known to fix leaky coolant systems . . . . . momentarily.

doesn't mean you actually fixed any problem with the car, just masking the issues.

 

[oilhammer]

Post #10... need to do some work with a scan tool and the EGR valves. Pouring stuff in your tank isn't doing anything.

 

[MrCypherr]

Well, technically both because the ports on the manifold clog up due to soot, But thats because how the EGR runs on these cars. The valve 'fails' because of the build up. So VW says to replace both the manifold and that valve, IF ITS the one on the manifold. Could also be the rear one, on the EGR Cooler.

 

[bashik]

Hello MrCypherr and Oilhammer ! Can you explain to me why soot in the pipe CJAA is the death of the filter, but soot in the CRUA pipe is normal?

 

[nectarguru]

Well, technically both because the ports on the manifold clog up due to soot, But thats because how the EGR runs on these cars. The valve 'fails' because of the build up. So VW says to replace both the manifold and that valve, IF ITS the one on the manifold. Could also be the rear one, on the EGR Cooler.

Well my CEL came back on after about 4 months so I decided it’s time to get my car properly diagnosed. I ran the scan at AutoZone yesterday which again threw the P0401 for the EGR valve but also the catalytic converter. The car is being diagnosed tomorrow by the dealer, but if the MK7 engine does not have the cracked DPF issue that the previous models does, what range of repair costs should I be looking at between the two EGR valves (depending on which it is) and the manifold? Car performance is still tip top. No sluggish acceleration or performance, no reduction in mileage, etc. Last week there may have been a misfire in the morning when I fired it up (it killed about a second after the car started), but afterwards it started fine. Never had the issue before or since.

 

[MrCypherr]

Off the top of my head, i cant really say what the prices will be. Although the scan at the dealer with the test plan should tell you easily what valve it is just by the fault code. You can replace the valve if its on the manifold and clean the ports on the manifold too. I know some people have had luck with that instead of replacing the manifold.

 

[nectarguru]

Thanks. Turns out the manifold is indeed dirty but the EGR valve is okay. That’s beyond my technical skill so I’m just washing my hands of it having the dealer do the job.

 

[whizznbyu]

Update! I added another bottle of LiquiMoly in the tank today

Super Diesel Additive? If so, how is this different from Opti-Lube or Stanadyne?