Hidden Corrosion on BMW (E39) M5

We really didn't know this hidden corrosion was present in the Rear Sills and Rear Jacking Points of this BMW (E39) M5!
This is a Nov 2002 BMW E39 M5 with 124,000 miles.
The corrosion was well hidden behind OEM factory seam sealer meaning that until you started pressing and poking certain sections you wouldn't believe how 'holed' it was.
We were stunned when the Right Rear 'Sill End' gave way with just thumb pressure!
As you can see, initially this M5 didn't look too bad but once it was stripped and we dug deeper we found a surprising amount of corrosion.
We were tasked with carrying out a tidy-up process on the underside rear chassis as the owner knew there was some corrosion present.
The giveaway on this vehicle was that corrosion was already present on the outer rear sill sections which means it's been growing for several years as it all starts from the inside first.
Both the Fuel System and the Rear Axle System (and all their ancillaries) were disassembled for access and correct assessment of the problem areas.
The Rear Sills and Rear Jacking Points were a major problem on this vehicle (as with most E39's), as well as the Fuel Tank Bracketry, the RACP Mounting Points, and the Boot Floor Curved Panel.
Watch us talk through the process and update you on the key stages of the repairs necessary to restore this BMW E39 M5 Rear Chassis and improve upon it's weather protection processes.
This work took 114 hours.
For more BMW E39 M5 content check our website here:
www.redish-motorsport.com/E39M...
Did you learn anything from this video, if so, drop us a comment.
Is there anything further you think we should add to this sort of video?
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Thanks for watching!

[@PowerslideSWE]

Both my M5's have been absolutely rust free, and yes I have looked :D Not winter driven is the key. Great job saving this one.

[@RedishMotorsportbmw]

Nice one!

[@richlee509]

Exactly keep them off the road when the crap weather comes which is basically all year lol

[@chiefrocka8604]

My e34 m5 no rust , no corrosion , no mention of either on any mot Lack of use saved it and that’s the key , summer use only going forward it’ll never rust

[@realmusicreallife]

Yeh i used to think like that. But life is very short so if you need to nip out and its raining then so be it. Just enjoy it and if things happen they happen

[@ralphlazio505]

@DK - Is that the culprit of cars getting ‘rusted’? Winter driving?

[@Jonathan-qz9kd]

I must say you do a proper job a lot of people don’t know how much work doing that sort of work is and how specialists it is. That’s done properly spot on!

[@RedishMotorsportbmw]

Thank you very much Jonathan - appreciate that!

[@cossied01]

Brilliant job .

[@stevensumner3146]

Another fascinating video, real-world factual detail. Thank you for sharing

[@jakeblair4215]

Excellent underside walk through

[@RCNITROPRODRIVERS]

Just noticed my rear jacking point on my 540 is gone as i was putting it on stands, My plan was to service the prop shaft cv and renew the whole suspension with all subframe and diff bushes control arms/bushes and ball joints and a set of BC coils so while I’m at it dropping the rear axle I’m just gonna drop the fuel tank and go to town on all the corrosion And your videos really helps visualize what I’m in for and what to look for! Realizing that to do any actual lasting work fuel tank needs to come down so I can get to all the corrosion and seal everything up once the repairs has been made To me, this is a summer only car. and seeing corrosion when I thought she was pretty clean is heartbreaking! Currently repairing my friends e36 witch had water in carpet for years and most of driver side (left) floor is the consistency of a biscuit Also made a floor repair on an incredibly rusty all year round daily e46 back a few years ago, so I’m not a complete newbie and seeing your videos and explanations really makes it less daunting to get started myself I quickly on my first e46 repair noticed how important it is to get all of the corrosion out and properly seal the repair A quick repair might look nice for a few years A good repair might last and look alright for 5-10 years A professional repair will look good for 20years if sealed good and cleaned every once in a while throughout the years

[@offworldnetwork]

Great transformation, can you do a video showing the process taking place? eg, the physical rust removal, localised media blasting, products you use, and their application? It would be very useful. Thanks

[@E39V8BMWM5]

Beautiful :p i`m loving the attention to details keep up the good work and videos!!!

[@adams7405]

Used to repair E39 at an official BMW bodyshop.Amazed how people treated nearly new cars.Impressed by the amount of high strength boron steel in it and very few injuries.

[@berwhaletheavenger]

I'm starting to see some Z4 Coupes in a very ropey condition now.

[@YootubeUK]

Having just addressed one of my non BMW cars, sills specifically and luckily nothing else, the creeping rust under factory seam sealer is an eye opener. Nice video as always, Redish!

[@RedishMotorsportbmw]

Many thanks Yootube!

[@Borgschulze]

I had a German delivered 525tds that was exported to Canada probably 10 years ago... the rear jack points were tipped up at the back, with a LOT more rust than this example in the video has... but it still lifted the car just fine.

[@JP-zo4nr]

Quality work

[@RedishMotorsportbmw]

Many thanks JP!

[@m5yo]

I’ve been watching some of your vids lately and the craftsmanship and love you have for these cars is amazing. I wish you were local to me but alas, I wouldn’t hesitate to hand over my 1998 E39 M5 into your care! A quick question if I may, the studs where the fuel line clamps go into, am I correct they are welded in? One of mine is missing, the previous owner hit a speed bump causing the entire clamp to sheer off...thanks and keep up your amazing work! All the best from The Netherlands.

[@Liamofloin]

Such a big job! But, amazing work done. Do the earlier 5 series, e34's have the same/similar issues? I'm looking for an e34 Touring, 520i or 525i. Thanks.

[@k0vve_]

My 523i rusted on exact same spot around the rear jacking point as this M5 but luckily not as bad. Still required some welding though. Interesting how all of these always rust from there and how well they hide it.

[@briangreen6602]

Have you looked at a thermal zinc spray for the bare metal ? If you watch the vids from Retro Power, they zinc spray all there cars and did some salt spray testing on various coated panel.

[@gerardstabley6464]

Could you share what sprayable seam sealer you are using. Or anyone know if they've mentioned it in another video?

[@jensleopold7436]

Nice job

[@MrZ676]

Quallity work, well done!

[@RedishMotorsportbmw]

Thank you! Cheers!

[@Ton7o]

Great video - what would you recommend as best way to check corrosion on an E39 and determine if can needs more work? Thanks

[@1kontrabida]

This is why u have to double or triple check cars that were exposed to snow and salt, if ur thinking of purchasing... Just a personal observation, i would have clean the all the things u took off with at least a brush and a degreaser, painted them and sprayed them with some lubricant /rust prevent instead slapping them back in, also replaced or repainted all the bolts, or made owner aware and offered as an extra service i mean would if went that far as doing some rust resto.

[@user-lp4dv]

Good work !!

[@RedishMotorsportbmw]

Thanks!

[@leedon74]

Oh, great work you do btw!!!

[@RedishMotorsportbmw]

Thank you! Cheers!

[@miroslavmoravcik2447]

What is the name of the original protective coating that you used?

[@DreddE34]

Really good Video, ihve learned alot from the Past Content, currently iam Saving my E34 Daylie, it had/has massive Rust Problems, mostly in the front bottom, a Thin Person could actually slip trough the big Hole, due to Water inbreak from Behind the Console somwhere, it was left there for likely 10 years before i bought the Car and checked it, however i got Into Welding from a Complete noob, i was scared of any Welding on the car, and now i feel like i could fix 90% of the Problems, also i learned, often if you Replace bad Metal, if you put new in, it does not have the exact same Shape of the old one, so you dont really need to buy every new shaped metal from BMW really, but thats just my take on it.

[@paullofty7028]

Any tips on removing the plastic trim along the under sides I want to remove and treat mine

[@farturinn]

I am very interested to know what this process costs,

[@ronan7812]

Very nice lads 👌

[@RedishMotorsportbmw]

Thank you kindly

[@TheNorthernmunky]

Utterly brilliant work! Only problem with being this good is that they’re booked up for donkeys!!! Great work though, really flawless finish. Should be mandatory on all M cars

[@tonistaru]

My opinion on cutting off the round spot welded flange on the boot floor is that the flat stitch welded solution is actually less strong/stiff than the factory join. The reason being one direction of rigidity is now removed. That said, I think it´s a good approach and I would have done the same, it´s near an edge anyway and the change in rigidity is probably without effect.

[@RCWatson]

Ah man I genuinely feel for the owner. I have a 2003 330i sport that in hindsight I should've cut my loses two years ago but started to try and sort the corrosion but it's too far gone..I've wasted a lot of time and money on it.

[@callummunro5400]

That’s too bad it’s a nice car.

[@diegosilang4823]

Also those nasty undercoating hide the rust pretty good as well. When you looking to buy a car, make sure you bring a magnet.

[@alimechs]

Can you do an E 32?

[@KillSwitchGarage]

very nice work done sadly that corrosion problems are present in our country aswell :/

[@stoveguy2133]

Exhaust is massive. 1 cat, rez and muffler? X2 seems quite bulky. And heavy.

[@mirzha001]

How much did this cost I am curious

[@IDriveUShoot]

29:49 was just comedic to me lol This is a whole car and it just went "crack"😂

[@matthewbell1968]

I was looking at getting an e39 but from what I've heard it's a £3.5k job, Japanese import it'll have to be I guess!

[@2403salman]

I was considering doing Poly bushings on the H-arm as well until I was told they’d wear out prematurely because that arm needs to be able to have some movement. I was recommended to go with either monoball or OEM rubber. Not sure how true this is. Would appreciate some insight if you can give any.

[@Dmxravin]

Very true. The flexible arm allows the wheel to hold the road at all angles giving BMW the road holding and grip it’s known for. Hence the reason why monoball or oem softer rubber is recommended solution.

[@RedishMotorsportbmw]

Good question Syed. I'd say rubber is probably best, however poly shouldn't be fully over looked. I guess time will tell but I wouldn't assume poly would wear out prematurely. I'd direct that question to Powerflex who'd be able to comment further with R&D data I'd assume.

[@theurbanegentleman4550]

What are your thoughts on under chassis cleanings available at carwashes? Do they actually worsen corrosion?

[@channelfiftyfive055]

I've wondered about that, myself. The aim is to try to wash out any salt that has accumulated That and dampness are worst for rust.

[@Life4DreamCar]

how much it costs?

[@465painkiller465]

What James is mentioning about repairing trapped corrosion is certainly correct and I’ve discovered on my car that it reaches a lot further in than you expect. I am restoring my e46 and tackling all the hidden and trapped corrosion on it. Making some videos on it that I will upload if anyone’s interested to see

[@465painkiller465]

I’m learning along the way and would not have been doing all this work if it weren’t for this channel! So many thanks to you for making these videos!

[@RedishMotorsportbmw]

Many thanks for the kind words Josef! Good luck with your E46 project.

[@laurencesnaterse]

Hi, A similar repair job is been done to mine e39 530i. Same rust at the door sills and jack points. All rotten metal was taken out and welded fresh metal in. new coating and paint and new paint on the door sills. The problem is, after 3 months i discoverd there was rust stains through the paint again at for instance the jacking point and but also at the end lip which was competely new welded in. I have had e discussion with the company, offcourse i was not really happy with this, but they don't take full responsibility for it (50/50 for a new job). Do you guys have any recommodations which products are best to keep is rust free at least a couple of years. Do you use a specific rust primer or anything? I do think the guys that did my job used poor products. Love to hear your opinion this.

[@RedishMotorsportbmw]

Hi Laurence, we see cars like this a lot actually (where we have to go over other peoples work). It might be poor product choice like you say? (we use Rust Converter chemical, Graphene Etch Primer, High Build Primer, Brushable Seam Sealer, Sprayable Seam Sealer, then finally Cavity Wax - 6 processes in that order). However, what seems more common is the fact most places (assuming it's probably a bodyshop?) don't seem to do much work 'under the car' in the dirty areas - especially bodyshops as most don't have great access to available lifts like a mechanical workshop does. So, if the 'underside' or 'dirty side' hasn't been attended to there's probably still old corrosion still trapped in between the seems of the metal like we note in our video examples on our KZbin channel.

[@laurencesnaterse]

@@RedishMotorsportbmw Thanks for you response. lets see if I can do some damage control knowing that all the hidden corrosion parts are all welded shut again, so i am not able to do much there i think. Very good video's btw!

[@m16msn]

I have an E39 525i Sport and had the rear jacking points repaired last year,I was shocked when I saw the extent of the rust after the plastic trims were removed.

[@SlickDan1]

How much did your repair cost you?

[@m16msn]

@SlickDan1 there was a hole in the drivers footwell and the boot also,so including both sills it was £1100 but there was a lot of rust to be cut out and new panels fabricated.

[@SlickDan1]

@@m16msn Thanks. Who did it for you, whereabouts?

[@m16msn]

@@SlickDan1 I'm in West Yorkshire.

[@SlickDan1]

@@m16msn Oh bit of a way to go for me then! Never mind, thanks for the ballpark figure anyway.

[@jorgex1604]

What an amount of work. Decent job though 👌🏻. I've scrapped a few non M E39's for parts over the last years and got the idea that the early models have less of an issue with rust than the later 2001-2003 models.. anyone recognizing this?

[@adams7405]

Water based paint from face-lift...

[@jorgex1604]

@@adams7405 yeah same here my daily is a 1996 528i with the single vanos m52. Really love it. Sort of started as a winter beater to keep my E24 out of the salt 10yrs ago 😅. Rust is not an issue on it so far. 🤞

[@billynomates920]

self-lubricating chassis system

[@rusu84]

Great job, can you tell me how much such work cost approximately???

[@cenksoylu3409]

I would also be very interested in that. If it doesn't cost a galactic amount, maybe I would combine that with a trip from Germany to UK Bristol haha :D

[@robertbrander7203]

Suprice...The E39s and E46 rusted as hell already upon roll out from the production line. Back in the day when I worked for BMW all panels almost were changed on warranty but rusted after a few years again😂😭

[@dawhitecastle]

Of course those are the two I recently bought. Both have a bit of rust but not too bad. The e39 has more though.

[@jamesroberts-yo8wy]

you said youve never seen problems with the rear jacking points im wondering coz i live in new zealand so dont have to worry with rust as much as you guys but ive noticed it seems like my jacking points have pushed up into the inner door jam is that something you guys have ever seen?

[@richlee509]

It's a weakness with some of these bmws with the jacking points not being that strong as a design flaw

[@adogmcdizzle]

These videos must help James break the news to the owners of these cars. Or warm them up before inspection… Like a doctor telling a patient they are seriously ill. If they come in knowing what to expect it doesn’t hurt so much.

[@RedishMotorsportbmw]

Well put Alex.

[@darrenwhite5544]

Wow 😳 mine is from July 2002. I'm gonna need to get mine done by the end of the year... Thats quite worrying to be honest

[@shamstar2k]

Bring a blank cheque with you

[@mickeymang6]

Good on the owner spending the cash to get this properly done.

[@voodoocars2134]

Do same era X5's suffer like this? I've been under mine and it doesn't seem too bad. Also, how much has this work cost the owner?

[@RedishMotorsportbmw]

We have an E53 X5 4.8is in with us at the moment as both rear corner boot trays has HUGE holes in them. Will possibly do a video on the process. Subscribe to us for the notifications. Many thanks.

[@Mehta555555]

Really should sort my rust out on my E39. 1 jacking point and both rear arches have rust.

[@Mash333]

The higher cost of living in SoCal seems worth it, after watching this.

[@mickeymang6]

I don't know any shops in the US that do this for BMW's.

[@cenksoylu3409]

Gladly also via direct message, I am very interested to know what this process costs, maybe I would combine that with a trip from Germany to UK Bristol :D

[@ErcleeIsBoss]

how much did this cost the customer?

[@TypeTuber]

Did you say 2000 pounds for a small piece of formed metal? Wow!

[@garywinterbottom6073]

It seems German cars of this vintage seem to rust on wings arches etc but french cars not so much?

[@4bimmer_ee_bmw_tuning_parts]

All e39s in Eastern Europe

[@Decrepit_biker]

I'm currently doing an underside restoration on my E90 335d and I'm surprised by just how much pitting I'm finding under the E- coat. I really wish BMW would have put better covering on underneath. That said no holes have appeared and it's now 16 years old so can't complain. And yes... this is Redish's fault I'm doing this..... 😂😂😂

[@royfontaine5526]

Yep BMW don’t even bother with proper underbody seal since e60 and e90 I believe, and rely on a basic e-coat. Pretty disgusting really. Though as you can see, underbody seal can end up hiding all kinds of nasties 😩 There has to be a better way...

[@adogmcdizzle]

@@royfontaine5526 the answer is that they only design it to last 15 years. If it makes it that long then they’ve met their brief. On my e46 it had quite a bit done under warranty at the 11 year mark. In that instance they did not do very well, and to their cost.

[@royfontaine5526]

@@adogmcdizzle I agree but it seems a shame. I suppose nothing lasts forever. But it’s sad having to call it a day on something like this...

[@RedishMotorsportbmw]

Haha sorry John! Hope it's going well! :)

[@HarrryHarrry]

Brake-Lines were already fixed (not in a good way), as you can see (really copper used???). Normally this corossion had to be recognized!

[@Arrozconchopsticks]

Scary

[@sintjinansley6107]

think i might have to bring you guys my 530i

[@thedean4431]

they should be going up in price more than they are e39 m5 s ..i have had mine for 18 years with 78k on the clock is this all worth doing or is it better money to strip them down and sell parts

[@shamstar2k]

Would be criminal of you to strip and sell it. Save up and get all rust issues sorted as I'm planning to do with my one. These are getting rarer with each passing year and are bound to rocket up in price in the coming years.

[@jamesstanding3364]

What rust converter do you use please

[@herrrechtschreibprufung7807]

mostly caused by the damp weather in the UK ….

[@kimkimpa5150]

Isn't it awfully dangerous to lift an E39 by its jacking points (like you do in the beginning of the video) when basically all jacking points on any E39 driven in northern europe are corroded to the brink of collapse?

[@johnkaimins9998]

The result certainly looks good, but unfortunately this video lacks showing the actual process of rust removal / welding / repairing, which would have been a more convincing display of your work.

[@_marcus_does_]

E36s would be the same?

[@RedishMotorsportbmw]

Quite possibly Marcus.

[@ToriL97]

It makes me sad seeing e39's like this and being driven in winter. They are gorgeous cars. It's sad so many of them rot out like this.

[@altblechasyl_cs2093]

It is 20 yrs old and should be at the junk yard for many years. Nobody in the factory planned with that the cars would be running more than 7 to 10 yrs. 🤷‍♂️

[@PowerslideSWE]

Couldn't agree more, fks sake, get a winter beater.

[@PowerslideSWE]

@@altblechasyl_cs2093 It's an M5, these were engineered in the early 90's and I can guarantee that the planned lifespan of the car was more than 10 years, modern cars have less end of lite time span.

[@altblechasyl_cs2093]

@@PowerslideSWE The designed life span will be round about 200.000 km for cars in this category of higher middle class. This means something about eight to ten years if the car runs the estimated 20.000 to 25.000 km per anno what is typically in this car category. 🤷‍♂️ That is official BMW strategy.

[@proxcess4946]

Its far sadder to own a car and not use it for 8 months of the year! What a waste.

[@alimechs]

Is it possible (E 32) ?

[@RedishMotorsportbmw]

Sorry, that's not a model we've done before.

[@dzgaming1]

114 Hours! How much did this all cost?

[@shamstar2k]

prob 8.5k

[@dzgaming1]

Parts and labor>?

[@ventsistoqnov6680]

💪🙂👌

[@iamyourfuture808]

I think the sensible answer is to avoid these old e39s like the plague

[@darrenboston342]

The old saying…. WTF. Don’t you look after your cars ffs🤔😡 James, amazing turn around buddy on this old girl👌 Shame the owners didn’t feel the way some people do about there cars tho ! Hope you guys are all god down there in Bristol🤔👍

[@RedishMotorsportbmw]

Hi Darren, hope you're both well! We're all good thanks! Many thanks for the kinds words as ever. Yeah it's a good transformation to save this chassis. The owner just recently just bought this car so wasn't responsible for any of the corrosion, however, he was doing the right thing for the car and getting the corrosion under control as soon as he started his ownership journey.

[@petrolhead28]

Fortunately the non m cars are cheap. Drive maintain the scrap if required. It's the shape and the drive I love.

[@repairitdontreplaceit]

the stupid plastic jack pads and the plastic under trims killed alot of e39s both of my alpina b10s had some . 2k undercoat or even epoxy resin is the best treatmeant , rubber underseal killed alot of cars to

[@paullofty7028]

Them plastic trims are a pain to try get off id like to remove mine and treat for rust

[@rusticagenerica]

What did those guys use such a low end metal, which leads to a beautiful car dying far too early? This is a pity

[@stevecooper6653]

IVE JUST HAD 2 brand new full sills galvanised fitted cost more than the cars worth.but ha Ho still a fantastic ride.all electrics work 👌🏻👌🏻lol lol (1999) E39 535iV8 full m Sport ) (139000)

[@RedishMotorsportbmw]

Thanks for sharing Steve. That's great news!

[@tomlyon4085]

How did this pass an mot

[@SajidHussain-lj5mr]

Because a Pakistani must of done the MOT 🤔

[@tomlyon4085]

@@SajidHussain-lj5mr 😅😅😅

[@lukealiaqua1018]

It’s a German thing. You wont understand.

[@esteemedenergy]

You should see what a 2018 F150does when it has rust - falls apart.

[@chiefrocka8604]

No offence there was clear tell tale signs on that it was a 5 Hitter You’d not buy that without proper rust scrutiny when there’s signs of corrosion clearly showing

[@chiefrocka8604]

If you think that’s good I’ve had miles better with zero rust and corrosion

[@soklot]

Damn rust, i hate it.

[@sats7819]

Every car in Europe. Then you get one from Spain and it has a bad repair and no service lol

[@paulvalente4140]

Literally car p0rn

[@RedishMotorsportbmw]

Thanks Paul!

[@GopNet]

0:21 is too painful to watch 😅

[@leedstown]

Probably £3000 for all this work?

[@shamstar2k]

add another 4k in my estimation

[@PT82]

@@shamstar2kAgreed. £3000 is way off lol. They’ll be charging at least £65 an hour and rightly so.

[@channelfiftyfive055]

Rust is literally cancer of the car. What is visible, can sometimes be just a minor indication of far more extensive damage.

[@sebastianspalding5016]

copper is way better than steel pipes as copper does not rust as easy everyone knows that !!!

[@RedishMotorsportbmw]

Did you watch the video we added to the top right? kzbin.info/www/bejne/j2LGoJmDnZVkY68

[@rusticagenerica]

DEAR GOD ! Shame to those for making such a car.

[@remzoo]

its a HIDDEN corrosion ? xDDDDDD

[@eggbirdtherooster]

Let us see the work instead of the results after it.. this is boring af

[@jaroslavzaruba2765]

lol it looks like a rotten wood

[@iwantmycountrybackkg4482]

Why wouldn't you ? So you know how much money BMW pay to advertise how good there cars are.A lot of people have fell for it ,(a bit like Brexit ) but hay ho .A lack of education is the problem in both.Its an old car whatever the badge.

[@peter3234]

Logically the car should have been scrapped. Not worth the money it cost to repair. Too many miles as well.

[@classiccarssp]

UK cars rust like... 😢

[@trevorgwelch7412]

BMW's Crap and Over rated . Buy Nissan