• Skip to main content
  • Skip to secondary menu
  • Skip to primary sidebar
  • Skip to footer
  • Home
  • Contact Us
  • Profile
  • Privacy policy
  • Sitemap

Garage Takeshi-kun (Kyoto, JAPAN)

Automobile Repair Shop in Kyoto JAPAN. Toyota, Nissan, Honda, Subaru, Suzuki, Mazda, Mitsubishi, and many other imported cars. Enjoy your car life!

  • Japanese Cars
    • Toyota
    • Nissan
    • Honda
    • subaru
    • Mazda
    • suzuki
    • Daihatsu
    • Mitsubishi
    • Isuzu
    • Motor Cycle
  • Import Cars
    • American Cars
      • Chrysler
      • Saturn
    • Italian Cars
      • Alfaromeo
      • Fiat
      • Lancia
    • German Cars
      • BMW
      • Audi
      • Smart
      • Volkswagen
      • Porsche
      • Mercedes Benz
    • French Cars
      • Citroen
      • Peugeot
      • Renault
    • North European Cars
      • Volvo
    • British Cars
      • Rover
    • Korean Cars
      • hyundai
  • Driving Skill
  • General Maintenance
    • Maruyama Molybdenum
    • Exterior Maintenance
    • True Stories
  • Handtool Selection
  • 日本語
You are here: Home / General Maintenance / What happens when you cool long-unchanged coolant? – An experiment with Super LLC past its replacement period –

What happens when you cool long-unchanged coolant? – An experiment with Super LLC past its replacement period –

4/21/2022 By ITS Leave a Comment

Currently, many vehicles use Super Long Life Coolant (hereafter, Super LLC) as engine coolant.

Similar to the previous Long Life Coolant (hereafter LLC), the main component is ethylene glycol, a polyhydric alcohol (ethylene glycol is a divalent alcohol because it has two hydroxyl groups in the molecule).

While conventional LLC required replacement every 2 years, Super LLC has benefited from advances in additive technology (rust inhibitors, anti-foaming agents, and others), resulting in extremely long replacement cycles – initial replacement at 7 years or 160,000 kilometers, or 11 years or 200,000 kilometers (whichever comes first).

Ethylene glycol is an environmentally harmful substance that becomes toxic when metabolized in living organisms. Proper waste disposal is paramount, but this extended replacement cycle can be seen as manufacturers’ efforts to reduce environmental impact.

In the era when cast iron cylinder blocks were mainstream, neglecting coolant replacement would cause the coolant to turn “rust red,” making inadequate maintenance visibly obvious. However, with today’s predominantly all-aluminum alloy engines, there is almost no visible color change even if internal corrosion progresses due to neglected coolant replacement.

A 19-year-old Toyota vehicle came into our shop.

The Super LLC had been replaced at least once 8 years ago, with earlier history unknown.

The manufacturer’s replacement specification is initial replacement at 7 years or 160,000 kilometers (subsequent replacements at 4 years or 80,000 kilometers, whichever comes first). (I believe the shorter interval for subsequent replacements is due to the water passage structure that makes complete replacement difficult).

TOYOTA(トヨタ) Super LLC 2L 08889-01005

The bottle on the left is new Super LLC (pre-diluted to 50%), the bottle on the right is Super LLC that hasn’t been changed for 8 years.

There is almost no difference in color or transparency.

I placed these two samples in the freezer overnight, simulating Hokkaido’s winter sub-zero temperatures. Consider it around -20°C.

While the new Super LLC remained completely liquid, the 8-year unchanged Super LLC froze into a sherbet-like state. In severely cold regions, this could potentially damage water passage components.

We can predict that rust prevention and anti-foaming performance have also deteriorated, so especially with Super LLC, it would be incorrect to determine replacement timing based on appearance alone.

Toyota Genuine Super LLC Pink 2L 08889-01005 Long Life Coolant High Performance Long Life TOYOTA

Buy on Rakuten

Filed Under: General Maintenance, True Stories

Reader Interactions

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

email confirm*

post date*

Primary Sidebar

Sponsored Link

The Journey of Takeshi-kun

[Read More…]

Readers Voice

    Past Posts By Month

    Recent Posts

    • Air Conditioning Malfunction Caused by High Refrigerant Pressure Exceeding Pressure Switch Limit (GBD-U71V Nissan Clipper)
    • Engine Warning Light On with No Noticeable Performance Issues (DBA-L175S Daihatsu Move P0325)
    • Recognizing the Importance of Suspension Components at 370,000 km: Replacing Arm Bushings (UA-SCP10 Toyota Vitz)
    • Can You Replace Suzuki Hybrid ISG Belt Without Special Tools? (Spacia DAA-MK53S)
    • When Engine Vibration Becomes Noticeable (Toyota iQ DBA-KGJ10)

    Site Search

    Article Recommended

    Footer


    This Website is Produced by ITS

    Official SNS

    • Facebook
    • Instagram
    • Twitter
    • YouTube

    Site Search

    Past Posts by Category

    Sponsored Link

    • 日本語
    • English

    Copyright © 2025 · ITS All Rights Reserved