Ring Apex First Edition
Audi B9 · A4 / S4 / RS4 · 2017–2023

Stop wasting time and money on a car that doesn’t deserve it.

Two S4s, both advertised as 2018. Only one has the rocker arms that don’t fail. A pre-purchase inspection guide for the Audi B9: 59 checks in the order you actually perform them, and what each finding is worth when it comes time to negotiate.

Worried you’re about to overpay for a car that’s ready to break?

Don’t want to drive five hours to find out it isn’t what was advertised?

Not sure what a fault is worth, or when to walk away?

Get the guide · $39

The repair it is built to catch is owner-reported at $4,000–$6,000 at a specialist.

Ring Apex

Field card

Section 07 · one page · 59 checks Cold start: one chance
Rattle in first 2–3 seconds
Ticking from top end
Built before 06 AUG 2018?
Blue smoke on start-up
White smoke that persists
Engine bay: torch
Rear valley: oil or coolant weeps
Expansion tank and hoses
The detail that starts the argument

Audi revised this part twice in fourteen months.

Three part numbers in just over a year, and which one a car carries is set by its factory build date, not the model year on the advert. Two cars sold as “2018” can carry different parts.

27 pages. 59 checks. Every repair cost sourced and labelled. Where no reliable figure exists, the guide says so.

Rocker arm part revisions by build date
Up to 11 Sep 2017 06M109417H
11 Sep 2017 – 6 Aug 2018 06M109417L
From 6 Aug 2018 0P2109417

The build date is on the VIN plate. The advert will not tell you.

Section 02: What fails, and what it costs

The inspection costs you a Saturday morning. The one you skip can cost $6,000.

Every figure carries its source. Estimator data means an independent repair-cost estimator. Owner-reported means owners who have had the work done: less precise, usually more honest.

Rocker arms and lifters

Cars built before 6 Aug 2018

Severe
Parts, DIY route~$2,000–3,000
Full job at a specialist~$4,000–6,000

Owner-reported: commonly an engine-out job

Timing chain tensioner

Reported most often on 2018 cars

Major
Tensioner only~$1,500–1,800
Full chain and guidesup to ~$3,700

Estimator data; full-job figure less firmly established

Turbocharger assembly

Wear-based, not tied to a model year

Severe
Parts~$2,550–2,870
Labour~$480–710
Total~$3,000–3,600

Estimator data, S4. RS4 is twin-turbo, expect higher

Cooling system

Water pump, thermostat, shut-off valve

Major
Water pump~$1,100–1,400
Combined jobs~$1,900–2,800

Water pump: estimator data · Combined: owner-reported

Oil filter housing

Plastic housing, mounted in the hot V of the engine

Moderate
No reliable published figure found.

On the RS4’s 2.9T a turbo may need to come off to reach it

These five come with a cost. Four of them have a price. One of them doesn’t, and that’s the more useful entry.

Why not just get a pre-purchase inspection?

You pay for an inspection once per car. You almost never buy the first one you inspect.

An inspection is bought per car, and it happens late, after you have found the listing, asked the questions, made the drive, and decided this car is worth paying someone to look at. Most of the cars you consider never get that far. This guide is bought once and used on all of them.

Section 3.1 runs before you leave the house. Photos of the VIN plate and the boot sticker. The service history. A direct question about track use and accident damage, asked before you have shown how much you want the car. If the build date, the records or the answers already rule it out, you have finished that inspection without leaving home, and without booking anything.

The cars that survive that filter are the ones worth a Saturday. The ones that survive the Saturday are the ones worth paying a mechanic for.

None of this replaces a professional inspection, and the guide says so in its own final checklist. A qualified mechanic on a hoist will always establish more about a specific car than you can in a driveway. What changes is which car you spend that money on. Get the inspection, on the one that survives this.

What you’ll be able to do

You don’t need to become a mechanic. You need to know what to do, in what order, before the money moves.

At the listing

Rule a car out from your phone.

Photos of the VIN plate and the boot sticker, the service history, and the questions to ask before you have shown how much you want the car. If the build date or the records rule it out, you are finished without leaving home.

Section 3.1 of the guide: the five checks to make before you leave the house

Field card: the “before you travel” block. Detail blurred.

At the cold start

Know what the first thirty seconds are telling you.

Which noises cost money, which are just a direct-injection engine doing its job, and why you only get one chance to hear the difference. Knowing what is normal matters as much as knowing what isn’t.

Figure 3.1: the three sounds to listen for in the first thirty seconds of a cold start

Figure 3.1: cold-start listening windows. Detail blurred.

At the car

Confirm it left the factory as advertised.

The PR code sticker under the boot floor itemises the entire factory build, and it cannot be edited by a listing. Cross-check it against the VIN and a diagnostic scan and you know what you are actually buying.

Section 4 of the guide: sample PR option codes and the VIN positions that matter to a buyer

Section 04: PR code sticker and VIN decode. Detail blurred.

At the negotiation

Turn a finding into a number, with the words to say it.

Each fault mapped to what it is worth off the price, and two scripts you can adapt. Including the rule that stops you asking for money the seller has already taken off, the most common way a private buyer loses a negotiation.

Section 5 of the guide: each finding mapped to what it means and what to ask for

Section 05: the leverage table. Detail blurred.

At the point of leaving

Recognise the findings no discount fixes.

Eight findings where the right move is to thank them for their time and go. Not because the repair is unaffordable, but because each tells you something a discount cannot fix.

Section 6 of the guide: the findings where the right move is to leave

Section 06: walk away. Detail blurred.

How this guide was built

You have no way to check whether any of this is true. So here is what was checked, and what didn’t survive it.

A wrong number, published once, gets repeated until it looks like consensus. That is the failure mode of most buying guides: they are assembled by collecting what has already been written about a platform and rewriting it.

This one was built the other way around. Every technical claim and every dollar figure was checked individually against manufacturer service specifications, parts catalogues with part-number-level records, published engineering investigations, independent repair-cost estimators and owner-reported invoices, rather than against any single article’s account of the platform.

Replaced

Brake inspection method

An earlier draft described a check that does not exist. Replaced with the correct procedure: measured rotor thickness against the MIN TH figure stamped on that rotor.

Corrected

Gearbox fluid interval

Corrected against the manufacturer’s own service schedule after an earlier figure proved wrong by a substantial margin. It is the number that predicts the expensive gearbox failure, so it had to be right.

Removed

Carbon cleaning interval

No platform-specific interval could be independently established. Numbers circulate, but they are carried over from other engines. The guide says so instead of repeating one.

Removed

Several failure points

Each rested on a single low-authority source and could not be confirmed anywhere independent, so each was cut. They may well be real. They are not established.

Written and researched by one person. My name is Griffin. The guide names its sources throughout, so you don’t have to take my word for any of it. Where a figure couldn’t be established at all, it leaves the gap visible rather than filling it.

Price

The cheapest thing that can go wrong on that list costs $1,100 to put right.

One file, everything in it. No tiers, no second product, nothing held back: the negotiation scripts and the field card are not a separate purchase.

Water pump (cheapest entry above)~$1,100
Rocker arms at a specialist~$4,000–6,000
The B9 Buying Guide$39

27 pages · 59 checks · printable field card
VIN and build-sheet walkthrough · negotiation scripts
Every source named · instant PDF download

Get the guide

Priced in USD, shown in your local currency at checkout. Delivered immediately as a PDF. No refunds for change of mind. Your statutory rights are unaffected. Refund policy

Questions

What you’d want to know before buying a PDF from someone you’ve never heard of.

Does this cover my car?

All three B9 cars (A4, S4 and RS4, 2017–2023) and both sides of the 2020 facelift, which is a styling and electronics split rather than a mechanical one. Section 01 covers working out which one you are actually looking at, because a badge swap is one of the cheapest modifications there is.

Most of the failure-point detail concerns the EA839 V6 in the S4 and RS4. The A4 runs a four-cylinder EA888 and is covered separately, including why the timing chain horror stories you will find online belong to an older generation of that engine and do not transfer to the B9.

I’m not in the United States. Are the costs any use to me?

The figures are US-sourced and quoted in USD, and the guide says so plainly. If you are buying elsewhere, treat the severity band as the reliable signal and the dollar figure as the starting point for a local quote; parts availability, labour rates and import duties vary enormously by market.

Everything else is market-independent: the inspection sequence, the build-date risks, the VIN and PR-code decode, the manufacturer service intervals, and the negotiation structure.

Can I use it on more than one car?

That is what it is built for. Section 3.1 runs before you leave the house: photos of the VIN plate and the boot sticker, the service history, and the questions to ask before you have shown how much you want the car. A car can be ruled out from your phone, and most of the cars you look at will not get past that stage.

Why are there no refunds?

Because the whole thing is readable in one sitting. The checklist and the negotiation scripts can be taken to a car, used, and then returned, which would make a refund window a free rental rather than a safety net. Change of mind is not refundable.

If the file does not arrive, does not open, or is not what this page described, that is a different thing entirely: contact me and I will fix it or refund you. Your statutory rights are unaffected either way.

Is this affiliated with Audi?

No. Ring Apex is not affiliated with, endorsed by or connected to AUDI AG or Volkswagen AG. Audi, A4, S4, RS4 and quattro are trademarks of AUDI AG, used here for identification purposes only.

What will show up on my bank statement?

Not Ring Apex. Payments are processed by Lemon Squeezy, which is the merchant of record for this purchase, so the charge appears as LEMSQZY*RINGAPEX. Your receipt and download link arrive by email immediately.

There is always another B9. There isn’t always another chance to check this one.

Get the guide · $39

27 pages · 59 checks · instant download

B9 Pre-Purchase Buying Guide $39, against a repair reported at $4,000–$6,000
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