MOT advisories re Corrosion - what would you do

[Lexguy64]

Just had the Mot done on my 57 reg RX400, got advisories regarding corrosion on the front and rear subframes. I asked the mechanic afterwards about options to which his comment was that the type of corrosion suggests it is a seaside car, I.e. corrosion being from the inside rather than surface rust. 
as it happens the previous owner did live by the coast, so seems that he has a point.

with it likely to be that it will only get worse do I get rid before the next mot or have you had similar advisories but it is still lasted a few more years.

what would you do?

[Russell Wheeler]

Mine is the same, and I do live by the seaside. 2020 was the 1st mention of corrosion underneath on mine.  Removed the spare wheel, cleaned and used hammerite on both subframes, then waxoyl all areas I could find. Seems to be keeping the worst of it at bay. Doing nothing means it will eventually rust away. The subframes should not rust out from the inside, if they have then it would have failed the MOT. The advisory must be for rust they can see (ie on the outside of the subframes). At 17/18 years old, you do need to expect they will be rusting underneath. Some older RX300 owners have had to have new subframes (or scrap the car)

[kenhall]

My experience is similar, living near the Irish Sea coast, however I believe that road salt is a bigger cause of corrosion than wind borne sea salt.

My last two MOT passes in January ‘23 and ‘24 both had advisories for rear subframe corrosion.  When the weather is more amenable I plan to pressure wash the subframe and then spray it thoroughly with Lanoguard.  I hope I won’t get chased by any sheepdogs!!.  If you have smelled Lanoguard you will know what I mean. Lanoguard is obviously derived from the greasy by product of the wool scouring process.

[Restorer]

On 2/6/2024 at 8:53 PM, Russell Wheeler said:

........ Doing nothing means it will eventually rust away. The subframes should not rust out from the inside, if they have then it would have failed the MOT. The advisory must be for rust they can see (ie on the outside of the subframes). At 17/18 years old, you do need to expect they will be rusting underneath. Some older RX300 owners have had to have new subframes (or scrap the car)

About a year ago my 2004 RX300 failed on rear subframe (amongst other things).

 

I found this place that imports cars from Japan to break for parts.

I got a subframe for £360. It was corrosion-free.

 

NIPPON AUTO SPARES LTD ★ 4.6/5 £360.00   Inc Delivery - Estimated 2-3 Working Days HOW TO ORDER BUY NOW ONLINE OR CALL QUOTING REF:  ☎ 01332 293399 Purchase securely online by Debit/Credit Card or PayPal. Never pay by bank transfer or cash.

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Quote Details LEXUS RX 300 SE | KO53EUE 2004 | 2995CC | 5 SP AUTO | PETROL | 5 DR ESTATE  SUBFRAME (REAR)  3 Months Gte | Used £250.00 Delivery - Estimated 2-3 Working Days £50.00 VAT @ 20% £60.00 Grand Total £360.00

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