I have a 2003 Lexus IS 300 (manual) do I need the radiator and the transmission flushed?

Question

Last time I had my oil changed they told me that i needed both services but I declined and decided to research it. I now see that there are drains and flushes, some say that a flush is neccesary, some say that they have practically the same effect and others say not to flush just to drain. Does anyone know what the truth is, in particular for my car? Thanks!

Answer 1

Flushing the radiator is a good idea. The transmission DOES NOT need a flush, just a drain and refill.

Answer 2

With a car that is about 5 years old, you should flush the radiator and refill with a 50/50 solution of water and anti-freeze. The coolant has additives that prevent corrosion and after this amount of time they have been used up.

The manual transmission should be drained and refilled with new fluid.

Good luck with the car.

Answer 3

just like investing, your time horizon should dictate your actions.
keep car , for 10 years, then flush
keep car for 2 more , just drain and fill.

how ever most cars transmissions can not be drained.
the fluid coupling stays full. full, as in full of filth.

The engine , every time you run it , it pushes acids in to the water jacket , very slowly ,
due to that we drain it, every 2 years.
flushing gets out all the acid. ( 5 year orange juice ?)
but draining does do a very good job , its just not perfect.
If you do it every 2 years , draining is ok.
if you delay , I recommend flushing.

The tranny is a whole different kettle of fish.
Flush it every time it says so in the maintenance schedule in your glove box, this operators manual says it , just look.

if you dont , then kiss off $2500 when it bites the dust.
the oil breaks down and even more, so when its hot.
the clutch packs put dust into the oil , really bad stuff.
if you dont get it out , it will kill the tranny.
(autos are dirty by design and they tons of waste fuel)
Hope this helps,

jtgh.