Parts for your 2007 Lexus Is-Radiator

2007 Lexus IS Radiator — What it does and how to look after it

Yes, a radiator is absolutely relevant and fitted to the 2007 Lexus IS range (IS250, IS350, and IS220d). Lexus/Toyota technical sources back this up: the Lexus Repair Manual for the IS (cooling section) specifies radiator removal/installation and coolant service, the Toyota/Lexus Electronic Parts Catalogue lists the Radiator Assembly for these models (e.g., 16400-38460 for many IS250 variants and corresponding 16400-31Axx ranges for IS350), and aftermarket manuals such as Haynes/Chilton cover the same component. So this model uses a conventional liquid-cooled radiator as part of its engine cooling system.

The radiator’s job is simple but vital: it pulls heat out of the engine coolant and dumps it to the air as the fans and airflow do their thing. On many auto trans models, the radiator also houses an in‑tank transmission fluid cooler, so it’s doing double duty. If it’s tired, owners may notice creeping temps in traffic, a sweet coolant smell, pink/white crust at the plastic tanks, or damp patches low in the bumper.

Servicing is straightforward. Lexus specifies Toyota Super Long Life Coolant (pink), premixed, with an initial change around 160,000 km or 10 years, then every 80,000 km or 5 years thereafter. Don’t mix coolants, stick with SLLC. When refilling, set the heater to HOT, use a spill-free funnel, run the engine to burp air, and top up the reservoir to the “FULL” mark once cool. Chemical flushes aren’t usually needed—clean drains and refills are preferred.

If the radiator needs replacing, go for a quality aluminium core with plastic end tanks (OE or reputable aftermarket). It’s smart to renew hoses, clamps, and the radiator cap at the same time, many owners also choose to replace the thermostat. For automatics, check the transmission cooler fittings and inspect ATF for any milky contamination. Keep an eye on the water pump area on 4GR/2GR engines for pink residue that hints at weepage.

• Quick checks: coolant level cold, cap seal condition, fan operation, and any leaks around the lower tank.
• Safety: never open the cap when hot, dispose of coolant responsibly—it’s toxic to pets.
• Time/cost: a careful DIYer can handle a radiator swap in an afternoon with basic tools.

Popular questions about the 2007 Lexus IS radiator

What coolant should be used?
Use Toyota/Lexus Super Long Life Coolant (pink), premixed 50/50. It’s phosphate OAT, silicate‑free, and designed for the alloys and seals in this cooling system. Avoid mixing with green or universal coolants to prevent additive clash.

How often should coolant be changed?
Typically 160,000 km or 10 years for the first change, then every 80,000 km or 5 years. If the radiator or major hoses are replaced, refill with fresh SLLC and recheck the level over the next few heat cycles.

Is it safe to drive with a leaking radiator?
Not recommended. Small seeps can become big leaks quickly, risking overheating and expensive engine or transmission damage (on autos with in‑tank coolers). Top up only to reach a safe spot and arrange repair promptly.