Product Reviews

B6/B7 Audi S4 Carbon Fiber Engine Covers + R8 Oil Cap


I recently found a user parting out his B7 S4 on Audizine and jumped on the chance to pickup some gently used pieces to clean-up my engine bay – most notably, an OEM Audi R8 Oil Cap and Relak Carbon Fiber Engine covers. While neither part does anything from a performance standpoint, they work together to dress up the S4 engine bay nicely along with my gunmetal JHM Intake Manifold, 034 Motorsport MAF Hose, and OEM RS4 Side Engine Cover.


The engine covers are no longer made, but were previously produced by a manufacturer named Relak. They are very easy to install, they literally just snap into place using the OEM rubber grommets and are a great mod. These have yellowed a little bit with age, but my OEM engine covers had some wear and tear so they’re a great upgrade for me.


The R8 oil cap is an OEM part however and still available. You simply unscrew your OEM oil cap and put this one on to install it; be careful there is no dust or debris on the cap before installing, as any dirt or containmanents will get into your oil (and engine) if you’re not careful…otherwise, this is a very easy mod to install. You can pick these up in many places, but eBay tends to be the cheapest:

 Pic  Title  Details
OEM Original Audi Chrome Oil Filler Cap Genuine part for various Audi VW Seat R8 Current Price: $57.9
# of Bids: 0
Ending: 11 days 13 hrs 52 mins
AUDI OEM 08-12 R8 4.2L-V8-Engine Oil Filler Cap 420103485B Current Price: $94.49
# of Bids: 0
Ending: 15 days 19 hrs 37 mins
AUDI OEM 14-15 R8 5.2L-V10-Engine Oil Filler Cap 420103485 Current Price: $81.84
# of Bids: 0
Ending: 19 days 4 hrs 26 mins
AUDI OEM 14-15 R8 5.2L-V10-Engine Oil Filler Cap 420103485E Current Price: $70.79
# of Bids: 0
Ending: 19 days 23 hrs 58 mins
Audi R8 Oil Cap 420103485B OEM Genuine Current Price: 152.9 AUD
# of Bids: 0
Ending: 14 days 17 hrs 37 mins
 View all items... (Powered by: WP eBay Ads)  

There is also a matching coolant cap, but these cost anywhere from $120-180 new which seems pretty steep for a part so trivial, so I’m going to see if I can find a used one otherwise skip that item.


That’s all I’ve got for now, but thought I’d post up a nice quick & easy mod since it had been a while since my last update!

Nick Roshon

Nick has been an Audi owner and fanatic for the last 10 years, and started Nick's Car Blog in 2009 to share DIYs and pictures of his A4. Currently he drives a 2012 Audi TT-RS, and has previously owned a B7 S4, B7 A4, and an 82 Audi Coupe (GT) LeMons race car. In his day job, Nick is a digital marketer and lives in San Diego, CA, USA.


  1. Hi need help with my 2006 audi S4 took of right head light to put electrical tape on wires on the inside cause they got striped from plastic sleeve put it back on and main bulb whont turn on

  2. Sounds like you might have pulled a wire loose? Does the dashboard say light out? Is the bulb secure? It’s hard to say where exactly to start, but I’d take the light off and check all of the connections first.

  3. What did you use on the intake hose from the air box? Is it a silicone hose that is readily available? BTW if you are ever in the market to move those engine covers give me a shout! They would look good on my dolphin grey S4 Avant!

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