The 07K Wiki - User contributions [en]

Forced Induction (Turbocharger)

2026-06-10T02:02:36Z

Featherman:

Over the years, a few turbo kits were made for the VW 2.5L platform. Some were available for all as where some were one-off builds from shops to explore the 2.5s abilities and to showcase their skills. Bluewater Performance, C2 motorsport, United Motorsport, BlackForest Industries, Unitronic, JDL auto design and more recently, CO motorsport all have built turbo set ups.

For good flow the oil return fitting should be installed in the upper aluminum pan, not the steel pan. For some swaps, like Mk1 a straight fitting in the engine plus a 90deg fitting on the oil return line puts the hose very close to the passenger side axle. A better approach is to weld or JB weld in a 90deg fitting, like this one -

[[File:Bulkhead Fitting.png|thumb]]

ARP hardware can help support higher HP goals.

Mains - ARP M9-1.0 X M9-1.25 4.060in OAL STUD
Part number: AI4.060-1B
You have to get m9-1.0 nuts separate.

Common Problems

2026-06-10T00:52:08Z

Featherman: Added tstat clip section

__NOTOC__

While the 07K is known for his outstanding reliability, there are still a few minors issues you might encounter. Don't worry though, they are relatively cheap and easy to fix!
==Leaking vacuum pump==
[[File:Vacuum block off plate.jpg|thumb|Deleted vacuum pump|363x363px]]
===Delete it===
Located right above the transmission, the gasket on the pump tends to fail and leak oil all over the transmission. You can easily confuse a leaking pump with a failed crankshaft seal.

The general consensus about fixing this issues is to simply delete the pump by using a block-off plate. This fix will make use of the engine vacuum to supply the brake booster instead of the pump. This configuration offer no drawback compared to the OEM setup.

'''For a list of brands who sells block-off plate, please consult: [[Aftermarket Parts]]'''
===Fix it===
There are also companies who sell kit to replace the worn gasket, this avoid the need to get a new pump and it's cheap.

For peace of mind, we would recommend removing the pump
{{Note|note-warning|In either case, ensure the vacuum line is hooked properly on a vacuum source. No vacuum will result in hard brakes and poor braking performance}}
==Knock sensors ==
===With time, they start hating water===
[[File:Knock-location.png|thumb|Location of knock sensors]]
Knock sensors use a sensitive piezoelectric crystal that generate voltage when it vibrates. They monitor knock / noise and report it back to the ECU so it can adjust the ignition advance accordingly

With wear, water and even humidity can affect the sensor ouput and set the engine in [[limp mode]] (EPC light might or might not turn on)

Located under the exhaust manifold, it will take less than an hour to replace them '''both'''.

'''Do not cheap out, if one fail, the other will possibly fail sooner than later.'''
{{Note|note-reminder|The tightening specification affect the function of the knock sensor. Torque them to 20Nm}}
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== Leaking PCV diaphragm ==
=== Rough idle ===
[[File:Torn-up-pcv.jpg|thumb|Torn PCV]]
The PCV diaphragm is located directly into the valve cover. It opens and close gradually according to the intake manifold vacuum, it vents the excessive crankcase pressure build-up into the engine.
The diaphragm tears causing a vacuum leak thus resulting in a rough idle.

Remove the oil cap, if there is vacuum holding the cap down, the PCV is bad.

[https://www.dormanproducts.com/p-54696-917-064.aspx Dorman] sell a repair kit for about 20$.

== Plastic Thermostat Flange Securing Clip ==

===Cheap, warps easily, will break in two and ruin your day===
The U shaped plastic retaining clip can be replaced with a steel OEM MK3 unit, like [https://kermatdi.com/i-2402-thermostat-flange-securing-clip-mk3-b4.html?q=thermostat+clip this one] sold by KermaTDI.

Forced Induction (Turbocharger)

2026-05-17T13:24:06Z

Featherman:

Forced Induction (Turbocharger)

2026-05-17T13:22:35Z

Featherman: Added fitting pic

Over the years, a few turbo kits were made for the VW 2.5L platform. Some were available for all as where some were one-off builds from shops to explore the 2.5s abilities and to showcase their skills. Bluewater Performance, C2 motorsport, United Motorsport, BlackForest Industries, Unitronic, JDL auto design and more recently, CO motorsport all have built turbo set ups.

For good flow the oil return fitting should be installed in the upper aluminum pan, not the steel pan. For some swaps, like Mk1 a straight fitting plus a 90deg fitting puts the oil return hose very close to the passenger side axle. A better approach is to weld or JB weld in a 90deg fitting, like this one -

[[File:Bulkhead Fitting.png|thumb]]

File:Bulkhead Fitting.png

2026-05-17T13:22:05Z

Featherman:

Good option for oil return, gives more clearance to the passenger side axle

Forced Induction (Turbocharger)

2026-05-17T13:16:07Z

Featherman: Added oil return info

Over the years, a few turbo kits were made for the VW 2.5L platform. Some were available for all as where some were one-off builds from shops to explore the 2.5s abilities and to showcase their skills. Bluewater Performance, C2 motorsport, United Motorsport, BlackForest Industries, Unitronic, JDL auto design and more recently, CO motorsport all have built turbo set ups.

For good flow the oil return fitting should be installed in the upper aluminum pan, not the steel pan. For some swaps, like Mk1 a straight fitting plus a 90deg fitting puts the oil return hose very close to the passenger side axle. A better approach is to weld or JB weld in a 90deg fitting, like this one -

Hard to Find Parts

2026-04-30T01:44:49Z

Featherman:

Some parts are getting hard to find, but we have solutions from the VAG parts bin.

The intake cam adjuster stretch bolt has several alternative part numbers:

- 06E109281A is the OEM VW part for NA 07K.

- N91042802 is the equivalent Audi part number, bolt is slightly longer but works for this application.

- Same bolt used in Porsche Cayenne and Panamera. Another avenue for you if VW doesn’t carry it.

Hard to Find Parts

2026-04-30T01:39:53Z

Featherman: Edited OEM part number

Some parts are getting hard to find, but we have solutions from the VAG parts bin.

The intake cam adjuster stretch bolt has several alternative part numbers:

- 06E109281A is the OEM part for NA 07K

- N91042802 is the DAZA part number, bolt is slightly longer but works for this

- Same bolt used in Porsche Cayenne and Panamera. Another avenue for you if VW doesn’t carry it.

Engine Repair Guides

2026-04-26T03:45:42Z

Featherman: Added a link for hard to find parts

[https://the07k.wiki/upload/a/a6/2.5_Engine_Break_Down.pdf 2.5 07K Engine Breakdown Guide]

[[Hard to Find Parts]]

Hard to Find Parts

2026-04-26T03:40:51Z

Featherman: Created page with "Some parts are getting hard to find, but we have solutions from the VAG parts bin. The intake cam adjuster stretch bolt has several alternative part numbers: - N91050202 is the OEM part for NA 07K - N91042802 is the DAZA part number, bolt is slightly longer but works for this - Same bolt used in Porsche Cayenne and Panamera. Another avenue for you if VW doesn’t carry it."

Some parts are getting hard to find, but we have solutions from the VAG parts bin.

The intake cam adjuster stretch bolt has several alternative part numbers:

- N91050202 is the OEM part for NA 07K

- N91042802 is the DAZA part number, bolt is slightly longer but works for this

- Same bolt used in Porsche Cayenne and Panamera. Another avenue for you if VW doesn’t carry it.