Rust concerns...

Mr_Groundhog · October 13

Has anyone else ever thought about rust? I was wondering whether to take the car in for rustproofing (undersealing) and the guy at the garage told me to first get in writing whether Lexus is OK with applying the very products they use to treat the surfaces, and so I did.

Unsurprisingly, Lexus replied with a vague, no-risk statement, which means if I take the car in and something goes wrong they'd wash their hands off.
I will indeed ask at the dealership about possible options but I expect them to not have much in the way of options for this.

I guess the forum question is: 🤔 given I'm planning on keeping the car for the next few years, how worried should one be about rust?
Things are ok so far, maybe some rust on the differential case, but I'm thinking about the future.

Banokles · October 13

Not worried at all.

High speed stone chips to the paint work only, and your undersealing wont help that. This is just not needed. All lexus and toyota cars have 10 year rust warranty - except Hilux. That differential case will never rust through. The bit that's not covered by the rust warranty is perforation, so your body panel is hit by a stone or whatever, all the paint and protection is gone, that bit rusts through, they cover that for 3 years i think. all chassis are galvanised etc and connected electrically, its just not gonna happen, if you're doing something so unusual that means it does happen, a bit of underseal is not going to help.

IS300FSPORT · October 13

It's certainly worth doing but the key is to get it done before the rust starts developing otherwise it's not effective. However I do recommend to get it done by a specialist people who day it day to day. As ideally certain components and plastic trims have to be removed to get into the sections that you can't usually reach.

Purchased a car before now an old boy had it done by a garage & they just covered the entire under chassis including the brake pipes making it deceiving, come MOT time the tester would just put down as advisory "brake pipes covered in grease or other material" as you don't really know the true condition.

I have an under carriage pressure washer & it seems to do a good job do it once a month from Jan-April, post winter removing the road salt is what causes it. Since owning mine over the last couple of years can't say i've seen the under chassis or brake pipes corroded. Wipe down the brake pipes still looking newish.

Setup Example

Mr_Groundhog · October 13

4 hours ago, IS300FSPORT said:

It's certainly worth doing but the key is to get it done before the rust starts developing otherwise it's not effective. However I do recommend to get it done by a specialist people who day it day to day. As ideally certain components and plastic trims have to be removed to get into the sections that you can't usually reach.

Yes thank you that was what they said. They are an undersealing specialists and they guy advised me just because another client who had a Tesla apparently had been told by Tesla not to do it, on the basis that some of the undersealing substances would eat into some of their Tesla pipes, cables, etc. All according to Tesla of course.

But yeah nobody wants to invest the money then end up worse off, and with the brand telling you the warranty is voided and it's on you.

I may look into one of those undercarriage accessories for my pressure washer, thank you 🙂

Also, there are products to revert rusting, so even if rust has appeared one can still revert + heal + seal. Or so i have been told.

PCM · October 14

Rust killed my R2003 X300 underneath. The engine was fine.

Sadly, it was not economical to repair.

I've used Lanoguard on my cars since...

The-Acre · October 14

2 hours ago, PCM said:

Rust killed my R2003 X300 underneath. The engine was fine.

Sadly, it was not economical to repair.

I've used Lanoguard on my cars since...

Lanoguard is brilliant, and so easy to apply.

DBIZO · October 14

10 hours ago, PCM said:

Rust killed my R2003 X300 underneath. The engine was fine.

Sadly, it was not economical to repair.

I've used Lanoguard on my cars since...

Does it make sense on a 9-year old car, do you know? Can existing rust be removed cost-effectively? I saw high pressure CO2 removal advertised. Then Lanoguard. Not sure about the costs though.

NemesisUK · October 14

The only sure way to remove rust is to cut it out. Not terribly practical in most cases but there are some effective rust converter solutions out there that do stop the process. Then underseal ..

Mr_Groundhog · October 14

Problem with Lanoguard is that you need to re-apply every year and I suspect the waxy-sticky texture it leaves is prone to pick up all the dust and sand in the world...It's good in the sense that's environmentally friendly but does it smell of sheep when you apply it?

Boomer54 · October 14

If you believe in the underlying science of rust converters then on the assumption that your corrosion was not yet structural in nature then in my view it is rational to apply the converter and then underseal preferably with a multi year solution. After all is it not correct to say that when we talk about rust we are usually talking about how we make sure surface rust does not become structural in a way that destroys the car?

If a rust converter and undersealing is still an economic proposition then why would you not apply it and extend the longevity if your car?

The-Acre · October 15

14 hours ago, Mr_Groundhog said:

Problem with Lanoguard is that you need to re-apply every year and I suspect the waxy-sticky texture it leaves is prone to pick up all the dust and sand in the world...It's good in the sense that's environmentally friendly but does it smell of sheep when you apply it?

Yes, it smells like sheep!

Boomer54 · October 15

I had mine done using a product called Corrolan. The website say's it is virtually odourless. Not even close. Smells like sheep even now 6 weeks later. Guess that will change, but whilst it lasts there is no disguising it is not a nice smell.

Linas.P · October 15

Rust isn't something to be "concerned" about, it is a simple matter of looking under the car and knowing whenever you have rust, or you don't have rust... also good thing about rust - it does not happen overnight. Even if there is some surface rust, it literally takes years for it to become serious problem, so usually there is plenty of time to device the plan of attack and resolve the issue before it get's very bad.

Obviously if you looking for preventative maintenance, then you need to apply whatever you applying before you get rust. I know many people praise Lanoguard, but I am just not sold on it. It needs annual application and that is just too much effort and cost just adds-up. For that reason I like to use "migratory" systems, like Bilt Hamber Atomac or Hydrate-80, it is easier to apply (does not require to perfectly cover everything as it is migratory, also does not care if surface is wet as it is water based anyway), last 3+ years, has no smell, does not attract dirt and works out cheaper (both in product an labour). Hydrate-80 can even be applied onto surface rust and still work (but I mean just light rust). If one is really really want to protect their car, then they can even apply Lanogiuard on top of Hydrate-80.

But the first step - go under the car and see...

e46guy · October 19

A 2014 and 2016 IS300h I looked at had rust on rear sill jacking point areas - this was actually worse on the 2016.

This part is not protected by any plastic undertray and only appears to be covered with primer.

Totally unacceptable for an 8 year old car of any make...

Linas.P · October 19

In theory shouldn't be a problem if people lifted the cars correctly and had rubber pads on their jacks as they suppose to, but people will be people and some of people who works on the cars really shouldn't... so I tend to agree with you - the part which is most likely to be abused should be reinforced and protected better. Even just having a little bit of rubber/plastic protector would go long way. It doesn't mean that cars are poorly protected from rust, but they are certainly poorly protected from idiots... and when idiots inevitably damages them.. yeah they will rust.

My GS300 is not really that bad for the rust, except of those jacking points which are completely mangled and the rust started spreading from there, there is little hole on on side of jacking point, that obviously then let's water into the sill and now there is a spot of rust in all direction from the jacking point. My plan is to get that welded and then also put tab made out of stronger metal over the jacking point to reinforce it. I will also do it on all 4 corners, because it will surely be damaged again.

dazzlar · October 31

I have had my 2015 300h from new, and it's looking pretty bad for rust if I'm honest. I'm going to treat and protect as much as I can next summer as I think to not, will cause issues in the next few years. My wife's Kia same age looks immaculate in comparison. I wish I'd treated it sooner.

GMB · October 31

I remember being horrified to find quite a bit of metal in the rust underneath my old Rover P6. The rear axle dropped off shortly after.

Notamech · October 31

6 hours ago, dazzlar said:

I have had my 2015 300h from new, and it's looking pretty bad for rust if I'm honest. I'm going to treat and protect as much as I can next summer as I think to not, will cause issues in the next few years. My wife's Kia same age looks immaculate in comparison. I wish I'd treated it sooner.

I tried it on the IS last summer. Honestly if you're trying to do it in your drive way with no access to a lift...its a massive massive pain. First of all a lot of the underside has plastic cladding. you need to remove all the panels to be able to truly treat everything. I didn't bother with this. Then theres the issue of you have to really get under the car which for some reason felt very scary..even after that you cant reach places like the top of the diff etc and the diff is the thing that looked most rusted to me. Then when you use a wirebrush to try and remove the rust you get rust particles all over you and in your face also since youre fighting gravity your arm starts to hurt trying to scrub everything down. Long story short i said f@#% it i dont really care anymore and gave up trying to do it properly. I then just brushed over whatever i could with some jenolite rust converter and called it a day.

DBIZO · October 31

10 hours ago, dazzlar said:

I have had my 2015 300h from new, and it's looking pretty bad for rust if I'm honest. I'm going to treat and protect as much as I can next summer as I think to not, will cause issues in the next few years. My wife's Kia same age looks immaculate in comparison. I wish I'd treated it sooner.

I don't have a problem with rust because I rather not look.

Mr_Groundhog · November 1

On 10/31/2024 at 10:36 AM, dazzlar said:

I have had my 2015 300h from new, and it's looking pretty bad for rust if I'm honest. I'm going to treat and protect as much as I can next summer as I think to not, will cause issues in the next few years. My wife's Kia same age looks immaculate in comparison. I wish I'd treated it sooner.

If you do, please update us with the solution you finally choose?

On my part, I'm due for annual service soon at Lexus, and since Lexus UK replied they do not approve of the products I was told the local specialist uses, I will ask them for alternative solutions.

I mean, if they say don't do this that way, should they not suggest an alternative?

As @Notamech said, a lot of the front is covered, but not so much in the rear, and it's mostly the differential casing where i saw surface rust.

PCM · November 1

... I used ramps and Lanoguard on mine.

Notamech · November 1

43 minutes ago, Mr_Groundhog said:

If you do, please update us with the solution you finally choose?

On my part, I'm due for annual service soon at Lexus, and since Lexus UK replied they do not approve of the products I was told the local specialist uses, I will ask them for alternative solutions.

I mean, if they say don't do this that way, should they not suggest an alternative?

As @Notamech said, a lot of the front is covered, but not so much in the rear, and it's mostly the differential casing where i saw surface rust.

I remember seeing plastic cladding in most of the middle sections as well (on the sides) . Not as much as the front though. And even at the rear. One strange thing i remember is the rear most plastic cladding (directly under the boot) was filled with small stones. Tapping it stones kept falling out. I remember thinking i need to open this cladding some day but then never got to it.

Infact just managed to find a pic on Google. As you can see other than the central portion of the car where the exhaust runs through everything else has plastic cladding.

Modano · November 1

1 hour ago, Notamech said:

I remember seeing plastic cladding in most of the middle sections as well (on the sides) . Not as much as the front though. And even at the rear. One strange thing i remember is the rear most plastic cladding (directly under the boot) was filled with small stones. Tapping it stones kept falling out. I remember thinking i need to open this cladding some day but then never got to it.

Infact just managed to find a pic on Google. As you can see other than the central portion of the car where the exhaust runs through everything else has plastic cladding.

Hey this is my car 😄 (lived in western France, very humid weather) until I brought her in the sunny side 🙂

Mr_Groundhog · November 1

This is the diff outer side I was talking about. Makes me wonder why they choose materials prone to rusting in some parts?

NemesisUK · November 1

3 minutes ago, Mr_Groundhog said:

This is the diff outer side I was talking about. Makes me wonder why they choose materials prone to rusting in some parts?

Cost and strength. Most diffs are made from cast iron for that very reason. The rust is only surface and the casting is thick enough for it not to be a problem