Purge valve
 

So just received a call back from Audi. Of course I have the infamous engine out vacuum line job (they want $7050 to do both sides, it will be going to the guy in New York!) but he said something about a purge valve leaking that would be $900 to do (I passed on that also). What is this purge valve? Only thing that comes up on here is a post from Zao but he’s talking about master and slave something dealing with software.

Also he quoted me $2000 for a tune up and oil change. I’ll do the oil change myself following John Engels YouTube video. Man they can be a total rip off!!!

Hi TeamJones
Its a Air Vacuum Purge Value Sensor ( Part No: 037906263 ) around £250 ...

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That's too bad about your vacuum leak. I've included a picture of a broken purge valve. The other picture is the operational purge valve which is located on the passenger side right side engine bay near the radiator fill spicket.

The purge valve is part of the pollution control system. The purge valve opens and allows fumes from the fuel tank to be consumed by the engine instead of the atmosphere. I'm suspicious of the diagnosis because if the passenger side right side vacuum lines are leaking they manage the EVAP system which involves the purge valve. What would be wonderful is if the purge valve was bad and causing your vacuum leak, unlikely. The quote they gave you for repairing the purge valve is ridiculous. The Audis and Volkswagens use the same purge valve. I remember paying about $50 on eBay from a OEM vendor.


So before you spend a lot of money what are the symptoms that lead one to think that there is a vacuum leak? No doubt your vehicle's vintage is subject to that problem.

Eric

Here’s what I got back in an email. Let me know if it opens on you alls end. If not I’ll try to screenshot each page and post.

The uploaded file came through. Personally my recommendation is more research is required before making a move. There are specific performance issues with a vacuum leak that are noticeable. The first issue usually is the vacuum pump on the driver side left wheel well is operating quite regularly. Pressing the brakes a couple times causes it to run is one symptom. The vacuum pump running while lightly accelerating is another symptom. Idle surge is another. Last but not least are there any DTC's? The trouble codes sometime show a lean condition or misfiring.

As for the purge valve being defective that normally would show a generic P code. Joe Perillo is the authorized Bentley dealer for the Chicagoland area. Perhaps if they are nearby a second opinion?

Yes. I could try to find time to go to the dealership (working 7 days for 3 months, 12 hours for the last 2 weeks and again next week) to get that second opinion. When I go pick the car up today I’ll run a scan and see what comes up (I might have to wait till the engine light comes on tho) and post my findings here. But as I have no clue what I’m looking for or dealing with I will rely on the feed back I get from the forum to guide me in the right direction and hope it can help others.

If she’s not 100% now and rides like a dream, I can only imagine how she will ride once I get everything taken care of!!

A cursory observation, sounds like the car is in decent shape. Pending codes will show up on a scan but not illuminate the check engine. Most people notice the vacuum leak problem based on what I stated earlier. From what I gather your car isn't being fussy.


By the way you undertook a big project with the front end. Changing the spark plugs isn't much compared to what you already did. As you stated time is a bigger challenge.

The tune up is not that bad huh. I might have to look into that. I have that workshop disk too. I wish someone had made a YouTube video on it. I’m really a visual hands on type of person hence why I took on the front end job, from all the post and instructions from here. I’ll try looking it up more. Thanks again and I’ll get those code for the board ASAP.

If it is just a plug change, I can talk you through it.....been there....done it.....

I'm not a video guy, but I can do written steps. First, before you start, the fun part is finding the plugs. NGK PZFR6Q-11 Laser Platinum

Here are a couple examples:
https://www.ebay.com/p/4x-NGK-Platin...965/1245100498


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Small update:

Went to pick the car up and kinda pressed him on why the purge valve costed so much. He indicated that that’s everything. The lines, valves and labor. As for the Vacuum leak, I told him about the guy in New York that makes the lines from steel even he was saying I would get them from him because they have them for around $260 each line. It’s a shame no one around here would really touch this car. It’s a few in Illinois that I could go to (Fluid something comes to mind) but no one on here really post about their experience with them or what not.

Coils don't typically get changed the way other wear parts do. Coils can, and do last a lifetime (whatever that means...haha). That said, early model year coils WERE problematic. The issue with a Bentley V12 is the effort it takes to get to them. The bad coils in the first few MYs (I believe 04 to 06) came up on a factory TSB. The factory replaced all the bad year coils that came in for service.

I'm doing this from memory (which isn't necessarily reliable), but I believe the bad coils were 07C 905 105s. Newer coils were 115s. I believe that is the way it went. When I got to mine, they were marked later. I would have changed them if they were needed, but looked to be correct.

Along with the spark plugs, you need two oetiker clamps for the two large vacuum tubes coming off the back end of the intake manifold. Second, you need the upper intake manifold plenum gasket. If you do this correctly and do NOT disassemble the intake manifold into pieces, you'll save hundreds as the single manifold gasket is $15 to $50 depending on who sells it compared to a couple hundred for the LS/RS manifold halves. Besides the plugs, you need:

1. Upper plenum gasket P/N 07C133238F
2. Oetiker clamps (2) P/N N10201801

On the Miller Motors kit, that's a fairly decent price for the coils and the plugs, along with the incidentals, keeping in mind ALL dealers make a fairly generous profit on pretty healthy margins

A gentle reminder, when pulling the spark plugs remember to blow out the recess. Accumulated debris down there can get into the cylinders when the plugs are removed. Also, if there is a lot of engine oil in the recess this is the time to replace the valve cover seals.

Good luck this is a fun project. Well at least rewarding.

Yeah Sage advice Eric....So many things I do as "good practice" over the many years, and I sometimes forget to mention things that are so automatic for me, that I assume everyone knows. Add to it - don't pull plugs out of a hot aluminum engine, let cool down completely, albeit pretty difficult to get everything off that you need to remove and still have a hot motor...haha.

Also, torque plugs to spec, and DO NOT apply anything to the threads. Old school used to apply anti-seize to spark plugs going into alum heads, which completely changes the "clamping torque" (clamp force). Plug manufacturers, NGK being one, now apply a dry anti-seize in manufacturing so the installer doesn't need to muck with it anymore.

Use some dielectric grease on the rubber boot and O-ring of the coil (NOT needed on the conductor). This keeps the rubber from drying out and burning onto the cam cover housing.

I'm sure I'm forgetting lots....but it'll come eventually...LOL...

Thanks guys!