Radiator — 16400-50280
OEM Part Number
16400-50280 — Radiator assembly, plastic top tank crimped onto aluminium core. Manufactured by Denso (OEM supplier to Toyota/Lexus). [Verified — Lexus parts catalogue]
What It Is
Main engine radiator for the 3UZ-FE 4.3L V8. Plastic/aluminium construction. The plastic top tank is the known failure point — see Radiator Plastic Tank Crack. Critical component — the 3UZ-FE is an all-aluminium engine and catastrophic damage can result from sudden overheating. [Probable — multiple forum reports]
Fitment
All SC430 (UZZ40) 2002–2010 with 3UZ-FE 4.3L V8. [Verified]
Aftermarket Alternatives
Recommended
| Brand | Part Number | Type | Price (USD) | Notes |
|---|---|---|---|---|
| Denso | 221-3175 | OEM-spec | ~$115-150 | Best option. Denso is the OEM manufacturer — this is effectively the same radiator without the Lexus box. ClubLexus owners report 6+ years no issues. [Probable — multiple forum reports] |
| Koyo / KoyoRad | A2419 | OEM-spec | ~$166 | Koyo is OEM supplier for many Japanese makes. Reported as perfect fit on SC430. Well-regarded. [Probable — ClubLexus reports] |
| CSF | — | High-performance | ~$250+ | High-end aftermarket. Full aluminium construction. Overkill for street use but excellent quality. [Reported] |
Avoid
| Brand | Why |
|---|---|
| TYC | Budget tier. Plastic tank quality inconsistent. [Reported — forum consensus] |
| APDI | Budget tier. Fit and finish issues reported. [Reported] |
| OSC | Budget tier. [Reported] |
| Unbranded eBay/Chinese | Unknown plastic tank quality — defeats the purpose of replacing a failed cheap radiator with another cheap radiator. [Probable — Leif’s mechanic suspects current radiator may be one of these] |
Where to Buy (Australia)
- Denso Australia — denso.com.au, or through Bursons/Repco trade accounts
- eBay Australia — search “Denso 221-3175” or “SC430 radiator Denso”
- Sparesbox — sparesbox.com.au, stocks Denso
- Amayama — amayama.com, genuine Japanese parts, ships to AU
- Amazon AU — check availability of Denso 221-3175
Pricing as at April 2026. Ask mechanic to check Bursons/Repco trade pricing first.
Installation Notes
- Relatively straightforward job — ClubLexus owners report completing it in an afternoon [Probable]
- Replacement radiators don’t include factory foam sealing/padding. Owners reuse old foam or use self-adhesive tape. One owner tested without foam — no temperature difference [Reported — single test]
- Refill with Toyota Super Long Life Coolant (pink)
- Bleed cooling system thoroughly after install
Related Faults
- Radiator Plastic Tank Crack — the primary reason this part needs replacing
Sources
- ClubLexus SC430 radiator replacement thread (2026-04-14 research)