Shop Our Clearance Sale - Up To 80% Off FREE SHIPPING on Orders $49+ *exclusions apply

Menu

Call Us330-331-2003 ChatLive Chat Text Us!
0 Shopping Cart
Your Vehicle Clear

Audi C7 S6 Quattro 4.0T

    • Audi
    • BMW
    • Mercedes Benz
    • MINI
    • Porsche
    • Volkswagen

Saved Vehicles

My Vehicles
You currently have no stored vehicles.

Recent Vehicles

Recent Vehicles Manage Vehicles

You currently have no recent vehicles.

We'll automatically keep fully selected vehicles here for your convenience.

Call Us330-331-2003 ChatLive Chat Text Us!
Track My Order View Order History Submit a Return Contact Us Wholesale Information Lifetime Replacement Returns and Warranty Information
0
Call Us330-331-2003 ChatLive Chat Text Us!
Track My Order View Order History Submit a Return Contact Us Wholesale Information Lifetime Replacement Returns and Warranty Information
Cancel
0
Sales & Specials
Enter Your Vehicle
garage-red
Your Vehicle Audi C7 S6 Quattro 4.0T
Your Vehicle Audi C7 S6 Quattro 4.0T
Change Clear

Audi C7 S6 Quattro 4.0T Cooling Expansion Tank Parts

Sort By
Filter By
Return to Top
This product has been superseded to ES#5477621

TGK Motorsport Coolant Tank AN Line Kit - C7/7.5 S6/S7

ES#4821589 - TGKacc02 - TGK Motorsport Coolant Tank AN Line Kit - C7/7.5 S6/S7 - top-tier solution to eliminate factory coolant line Failure - TGK Motorsport - Audi

top-tier solution to eliminate factory coolant line Failure affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
TGK Motorsport - Corporate Logo
ES#:
4821589
Mfg#:
TGKACC02
In Stock
$256.99

This product was last offered at the strikethrough price on
04-20-2026

$229.99 USD
Free Shipping

Porsche 911 Expansion Tank Cap

ES#3496004 - 99110645702 - Porsche 911 Expansion Tank Cap - Black and satin aluminum colored coolant cap from the Porsche 991. - Genuine Porsche - Audi Volkswagen Porsche

Black and satin aluminum colored coolant cap from the Porsche 991. affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Genuine Porsche - Corporate Logo
ES#:
3496004
Mfg#:
99110645702
In Stock
$53.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Audi R8 Expansion Tank Cap

ES#4691207 - 420121321 - Audi R8 Expansion Tank Cap - Keep proper pressure on your coolant, replaces any modern blue or black cooling cap - Bremmen Parts - Audi Volkswagen Porsche

Keep proper pressure on your coolant, replaces any modern blue or black cooling cap affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms 10X Entries For Our 25th Anniversary Sweepstakes!

Brand:
Bremmen Parts - Corporate Logo
ES#:
4691207
Mfg#:
420121321
In Stock
ON SALE! SAVE 14%
$34.99

This product was last offered at the strikethrough price on
05-02-2026

$29.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Expansion Tank Cap

ES#253082 - 3B0121321 - Expansion Tank Cap - Keep proper pressure in your coolant system - Genuine Volkswagen Audi - Audi Volkswagen

Keep proper pressure in your coolant system affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
253082
Mfg#:
3B0121321
In Stock
25% off MSRP

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$39.59

This product was last offered at the strikethrough price on
01-08-2026

$29.67 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

CTS Coolant Tank Cap

ES#4620720 - CTS-ACC-009 - CTS Coolant Tank Cap - Lose the plastic! - CTS - Audi Volkswagen

Lose the plastic! affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
CTS - Corporate Logo
ES#:
4620720
Mfg#:
CTS-ACC-009
In Stock
$69.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Coolant Expansion Tank Cap

ES#3485290 - 2Q0121321A - Coolant Expansion Tank Cap - Keep proper pressure in your coolant system - Genuine Volkswagen Audi - Audi Volkswagen Porsche

Keep proper pressure in your coolant system affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
3485290
Mfg#:
2Q0121321A
In Stock
2% off MSRP

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$42.99

This product was last offered at the strikethrough price on
02-26-2026

$41.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Expansion Tank Cap

ES#10026 - 3B0121321 - Expansion Tank Cap - Keep proper pressure in your coolant system - Vaico - Audi Volkswagen Porsche

Keep proper pressure in your coolant system affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
We Price Match - Give Us A Call or Chat!

Brand:
Vaico - Corporate Logo
ES#:
10026
Mfg#:
3B0121321
In Stock
$15.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Audi R8 Expansion Tank Cap

ES#2149010 - 420121321 - Audi R8 Expansion Tank Cap - Keep proper pressure on your coolant, replaces any modern blue or black cooling cap - Genuine Volkswagen Audi - Audi Volkswagen Porsche

Keep proper pressure on your coolant, replaces any modern blue or black cooling cap affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
2149010
Mfg#:
420121321
Ships in 1 day
9% off MSRP

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$326.99

This product was last offered at the strikethrough price on
02-26-2026

$298.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Coolant Expansion Tank Cap

ES#4858532 - 2Q0121321A - Coolant Expansion Tank Cap - Keep proper pressure in your coolant system - Bremmen Parts - Audi Volkswagen Porsche

Keep proper pressure in your coolant system affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms 10X Entries For Our 25th Anniversary Sweepstakes!

Brand:
Bremmen Parts - Corporate Logo
ES#:
4858532
Mfg#:
2Q0121321A
In Stock
ON SALE! SAVE 22%
$19.99

This product was last offered at the strikethrough price on
05-02-2026

$15.50 USD
Free Shipping
on orders $49 and up

Coolant Expansion Tank

ES#4004609 - 4G0121403AC - Coolant Expansion Tank - Coolant level sensor enclosed in tank - Rein - Audi

Coolant level sensor enclosed in tank affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
We Price Match - Give Us A Call or Chat!

Brand:
Rein - Corporate Logo
ES#:
4004609
Mfg#:
4G0121403AC
In Stock
$55.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Expansion Tank Cap

ES#2709040 - 3B0121321 - Expansion Tank Cap - Keep proper pressure in your coolant system - URO - Audi Volkswagen

Keep proper pressure in your coolant system affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
We Price Match - Give Us A Call or Chat!

Brand:
URO - Corporate Logo
ES#:
2709040
Mfg#:
3B0121321
In Stock
$5.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Expansion Tank Cap - Black

ES#3690266 - 5Q0121321 - Expansion Tank Cap - Black - Keep proper pressure in your coolant system - Vaico - Audi Volkswagen Porsche

Keep proper pressure in your coolant system affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
We Price Match - Give Us A Call or Chat!

Brand:
Vaico - Corporate Logo
ES#:
3690266
Mfg#:
5Q0121321
Ships on Sep 29, 2026
$18.99

This product was last offered at the strikethrough price on
04-02-2026

$12.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Coolant Expansion Tank

ES#3679602 - 4G0121403AG - Coolant Expansion Tank - Coolant level sensor enclosed in tank - Genuine Volkswagen Audi - Audi

Coolant level sensor enclosed in tank affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
3679602
Mfg#:
4G0121403AG
Ships in 1 day
9% off MSRP

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$158.99

This product was last offered at the strikethrough price on
02-26-2026

$144.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Expansion Tank Cap Seal

ES#302264 - 1H0121687A - Expansion Tank Cap Seal - Seals the expansion tank cap to the reservoir. 28.5x3.8 - Genuine Volkswagen Audi - Audi Volkswagen

Seals the expansion tank cap to the reservoir. 28.5x3.8 affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
302264
Mfg#:
1H0121687A
In Stock
$6.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Coolant Expansion Tank

ES#4039536 - 4G0121403AC - Coolant Expansion Tank - Coolant level sensor enclosed in tank - Behr - Audi

Coolant level sensor enclosed in tank affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Behr - Corporate Logo
ES#:
4039536
Mfg#:
4G0121403AC
Ships in 1 Business Day
$69.99

This product was last offered at the strikethrough price on
04-06-2026

$66.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

T25 Torx Screw - Priced Each

ES#4790 - N90775001 - T25 Torx Screw - Priced Each - Install new hardware with your new parts. 4.8x16 - Genuine Volkswagen Audi - Audi Volkswagen

Install new hardware with your new parts. 4.8x16 affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Used to secure the coolant expansion tank

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
4790
Mfg#:
N90775001
In Stock
ON SALE! SAVE 82%
$7.99

This product was last offered at the strikethrough price on
05-14-2026

$1.40 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

More About Cooling Expansion Tank Parts

A common source of overheating problems is a broken or leaking coolant expansion tank. Replace it with an OEM coolant expansion tank or quality aftermarket expansion tank to prevent future woes.

ECS Tuning is not affiliated with any automobile manufacturers.
Manufacturer names and/or part numbers are used only for identification purposes.

Terms of Use Privacy Policy ECS Tuning is part of Enthusiast Auto Holdings