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u/Interesting-Carpet66

PCV Gone?
▲ 1 r/Golf_R

PCV Gone?

Hello!

New owner of a r 7.5 here, wanting to share some doubts.

The car is completely stock with arround 74000km from 2018. Maintenances done at VW at the recommended intervals.

I’ve done the oil cap test on idle and it seems like a high vacuum and the rpms increase. Yesterday I saw a bit of smoke on hot start after sitting for 1h aprox. But today on cold start none of it. The PCV is probably never been changed so ill be doing it anyways, just wanted to know if this is normal or its already broken. Also Ive seen a small puddle of oil on the TIP just where the PCV pipe is.

Thanks for the help!!

u/Interesting-Carpet66 — 3 days ago
▲ 1 r/Golf_R

Hello,

I’m in Germany checking out a 2017 Golf R (310hp) with 70000km. I found some data in the ECU that has me a bit paranoid and I’d love some expert eyes on it.

The Context:
When we arrived, the battery was almost dead (11V). We had to clear a massive list of phantom DTCs before starting. I didn't check the pre-ignition counters before clearing, so I don't know if they were already there or if they are "legacy" data that doesn't reset with a standard DTC clear.

The Conditions:
• It was a very rainy/humid day during the test drive.
• Spark plugs were last changed in 2021 (meaning they have roughly 45k-50k km on them).
• Tank was almost empty (~10L of 1 month old 95 octane fuel).

The Data (Post-test drive):
• Cylinder 2: 62 "Lambda Shift" events and 36 "Torque Reduction" events.
• Misfire counters: Solid 0 on all cylinders (last 1000rpm).
• Fuel Pressure: 133.5 bar.
• Lambda adaptation: -3.9%.
The car felt 100% smooth during the drive—no stutters, no hesitations, and a perfect idle.

My questions:

  1. Do these UDS pre-ignition counters clear when you wipe standard DTCs?
  2. Is it possible these are just old events from the last 5 years of usage?
  3. Given the old plugs and the rainy weather, could this just be the ECU being extra sensitive with the protection maps?

I’m worried about a leaky injector, but the smooth idle and fuel pressure make me think otherwise. Any thoughts? Thanks

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u/Interesting-Carpet66 — 16 days ago