635 CSi or an M6 - which would you get and why?

[bigbilly]

I've got the itch to expand my BMW stable from its humble beginnings. Is one car a "stable"? :)

The E24's are looking better to me every day. As I look around on roadfly/craigslist/autotrader/bf.c, I see plenty of 635's and M6's to choose from.

The hardest part for me is figuring out where to start, specifically whether to chase a 635 CSi or an M6.

Unlike my e36, I am looking for an unmolested e24 and would plan to keep it stock.

Does anyone have any suggestions for me? I know for today's M's there is a strong difference, but for these 20 year old cars, is there as much of a difference between the 635 and M6?

It wouldn't be a daily driver (obviously), and I'm interested in doing most repairs myself, so as long as parts are available/findable, I *think* I'd be ok there.

Any guidance? If you were starting new, what would you get and why?

[e24mpwr]

If you don't have a specific reason to buy an ///M6, I would go with a 635. Find a stick if you can. M6's are more maintenance intensive and can really eat your wallet alive, even for examples that have lived a pretty good life (ask me how I know). Some things in the motor wouldn't be DIY, either.

A nicely-preserved 635 5-speed is a kick to drive and will satisfy your craving for a beautiful car to look at while respecting your life savings.

If you decide to go the M6/M635 route, it would be a good idea to get a strong education on them. There are some big gotchas for an unaware buyer.

I went with a Euro M635, but if I could have had a Euro 635 in as nice shape, I might have gone with that knowing what I know now...

[JayM]

If purchase price and added cost of maintenance isn't an issue, go for the M6. For one, it's hard to find an 635CSi with a manual gearbox, and all of the Ms are 5 speed OD. As well, if you're sticking with stock, the M6 has about 50 more horses.

On the other hand, the S38 engine in the M can be costly for maintenance, and potentially bankrupting if it needs major work. It's not for the faint of hear for DIY either - mistakes can be costly. I say this based on others' experience, since I've never cracked one open myself.

Personally, while I sort of like the older cars, the only ones that really interest me are the Ms. It never ceases to amaze me the level of performance in a 20+ year old car (just rent some of the stuff on offer today to get an idea). Another reason is the limited production ensures that a good one, or a good restoration, will retain it's value, if not increase. Of course, I wouldn't count on 5-figure prices in our lifetimes. They don't have the nostalgic value of a '71 Hemi 'Cuda or the rarity of a '58 300SL, and will never likely fetch that kind of coin.

[JayM]

Oops, e24MPower posted while I was typing. As you can see, we more-or-less agree, though I prefer the M for other reasons.

[GWL]

I agree with all that has been said. I owned an 80 Euro 635 CSi and now own an 87 M6. The surprising thing is that the 80 Euro (E12 based) was more nimble and pulled just as strong as the M all the way to 5500 RPM where the M6 feels a little stronger. This despite the 3.07 rear end in the Euro. Although it is great fun, 18 Months of ownership of the M6 has cost almost as much (it was in very good shape when I bought it), as I spent in over 25 years of ownership of the Euro.:rolleyes:D

[e24mpwr]

Oops, e24MPower posted while I was typing. As you can see, we more-or-less agree, though I prefer the M for other reasons.

LOL - you and I are pretty close, and we wound up with pretty much the same car. I love the looks of the Euro, the rarity of my M635 and the performance of the M88. I went looking specifically for an ///M car. My main point was that if you aren't looking for it specifically, a nice 635 fits the bill.

Mainly this year has been a tough one in a lot of ways, not the least of which is financially, so right now the cost of what I did to the M635 this year (new tranny, new timing chain/tensioner/rails, dual row conversion, valve adjustment and new rear brakes, not to mention new tires all around) seems a little pricey, despite the fact that Haygood is extremely reasonable - it has just been one of those years where everything adds up.

[jdkirkk]

The 2 differences I recall from my M6 was (1) the ride was stiffer and (2) it just kept going up in speed with little effort. The 635 cruises at around 95 without effort and the M6 will do much more than that, an easy 120+, without effort. (But where can you use it?)
Unless you are going to use it on the track I think the M version is really more than you need in the U.S.. The standard 635 does just fine and it is plenty to take care of mechanically.
The BMWCCA has a special section just for the M6 and you must get their info sheet from Stan on what you need on the engine before you buy the car. Know what you are getting into before the fact. I stayed ahead of the game and never had any serious bills to pay but I only had mine for about three years and actually drove it very little.
The problem with the late 635's is they started loading it up with gadgets, like that air ride crap, the involved air conditioning, and the expensive exhaust system. Find a very nice '85 or 86 with a known history, a manual transmission and a light color (black is tough to keep clean) and keep it garaged. The leather will probably need attenion even in a well cared for example. And if you want a late model 635 you can switch the auto trans for a manual. The type of tire is critical on these cars since the handling is such a joy.

[bigbilly]

Thanks to all of you for your thoughts. It's definitely helpful!


The BMWCCA has a special section just for the M6 and you must get their info sheet from Stan on what you need on the engine before you buy the car. Know what you are getting into before the fact.

I'm a member. How do I get into the section? Is this a SIG or a part of their forums or what? I'm locked out of their website for the evening...


Find a very nice '85 or 86 with a known history, a manual transmission and a light color (black is tough to keep clean) and keep it garaged.

I have my eye on an '86 red 5-speed 635 that - from pictures - looks compelling enough to investigate. And it's close enough that I can.

I just wasn't sure whether to leap at this one or hold out until the right M6 comes along. But considering my disposable income combined with homeowners insurance and property taxes in Florida, maybe the 635 is the right call!!

Thanks for all your help.

BB

[wokke]

both have advantages and disadvantages. When I bought my first M635 (Euro of course) I was kind of disappointed about the low end power. I was the proud owner of an E28-535i at that time. But high end power and top speed of this car is something else. A quick down shift when you want to pass another car and you just fly by.
And last but not least it is the rarity of this model which keeps value up and then just look under the bonnet and compare :)
Since I'm just a week man with having problems to make a decision once in a while I got one of each :stickoutt

http://www.aaa-car-imports.com/BMW-E24-M635CSI/Restauration/Endergebnis/19.JPG

http://www.wokke.de//BMW-E24-635CSi-85/Motorraum/635CSi-engine_02.JPG

[bigbilly]

wokke - Thanks for the response.

I think I understand the points raised on whether or not I'm "looking for an M-car". I think the answer is that I could be, if I understand the difference.

As an example, while I wouldn't turn down a new M3, today's 335 would be enough car for me. Do you think the difference in performance is as wide in the e24 as it is in today's M vs non-M vehicles?

I guess the simple answer is that I need to get behind the wheel of one of these - and maybe one of each.

jdkirkk - while I realize tire choice is often more controversial than politics, religion, or brand/weight of oil, what do you recommend for the e24?

Is there someplace I can go to get smart on these cars? I've got my M6 enthusiast companion book ordered from Amazon, so I'll be learning more soon enough.

[amibuggnu]

Is there someplace I can go to get smart on these cars? I've got my M6 enthusiast companion book ordered from Amazon, so I'll be learning more soon enough.
Big Coupe Group is an E24-dedicated site & forum with a great range of technical info on both the standard 635 and the M versions.

http://www.bigcoupe.com/

The BMW M registry is a good reference guide on the M6/M635CSi.

http://www.bmwmregistry.com/model_faq.php?id=5

[sixseries]

if you honestly dont care about the money part go get a nice M635 and make sure its the euro catless version. if money is an issue then get a 635 5 spd.

[GWL]

I agree with this with the exception that if you go for an /M635, then be sure any Euro version already has the double row timing chain and the improved valve spring modifications. Although the /M6 has fewer HP stock, it does have these mods as furnished by the factory. Further, be sure that the federalization has been done right as there were a lot of butcher jobs done when the Cats, lighting and other items were added or modified to comply with EPA & DOT import requirements. All said and done (IMHO) the /M series six is a big bite for someone without access to a mechanic or friend with a lot of BMW experience. But, as previously stated, if money is not an issue, the /M is a very rewarding six.:buttrock

[88m53453]

Pretty much in agreement with what has been said here and I'll repeat what I have said over the past 20 years
Buy the M car if :
You can wortk on it yourself or you have someone you absolutely trust to not "take you to the cleaners"
AND you can afford either downtime or have $$$.

I'll take the other side and say if you are going to drive the car as an alternative, the M car could be a good choice, it won't have much wear on it while you are driving it AND you have other transportation. If I wasn't getting an M car if I were in your shoes. I would try tp get the euro version for the nicer bumpers and more power, My highly modified 79 635 was as fast as a stock M car on the track and would idle nicely and get 25mpg . Admittedly,it took $$ to get it do this, but it was simple and fast with no turbo

[GWL]

My highly modified 79 635 was as fast as a stock M car on the track and would idle nicely and get 25mpg . Admittedly,it took $$ to get it do this, but it was simple and fast with no turbo I agree with this. I had the same experience when comparing my 80 Euro 635 CSi to my 87 M6. Although I never came close to 25 MPG with my 80. 19.5 was the best I ever got while on a cross country trip.

[JayM]

I agree with this with the exception that if you go for an /M635, then be sure any Euro version already has the double row timing chain and the improved valve spring modifications. Although the /M6 has fewer HP stock, it does have these mods as furnished by the factory. Further, be sure that the federalization has been done right as there were a lot of butcher jobs done when the Cats, lighting and other items were added or modified to comply with EPA & DOT import requirements. All said and done (IMHO) the /M series six is a big bite for someone without access to a mechanic or friend with a lot of BMW experience. But, as previously stated, if money is not an issue, the /M is a very rewarding six.:buttrock

I disagree that the double row conversion needs to be done, but you do need to make sure the chain, guides and tensioner have been replaced fairly recently, or allow for that in your price. The valve spring mod is another story.

I do agree that the federalization work needs to be well documented and make sure it was well done. Frankly, I'm glad I didn't have to worry about that.

Your (the OP's) best bet is to get a US spec car (if you go for the M), as BMW has already done the engineering for you. Most people I've spoken with say they can only tell the difference at the top end, and the US spec has better low RPM performance.

[jeffcfp1]

Not sure what you will gather from my comments:
I have both, a US M6 purchased in July of 07 and a 635 automatic purchased several months later, both 1988, which my wife drives. Neither is an everyday driver. I wouldn't drive a M daily, and unless you buy one is phenomenal condition, which will retain tremendous resale value, you are probably waisting your money on repairs and maintenence, unless you are like me and don't mind pouring it into your baby. I drove a non M first when deciding to get into a six, I expected more power as my Infiniti I 30 seemed so much more powerful, so I decided to find this car (ie body) with a higher level of performance. M to the rescue, love the performance. In summary, I pretty much agree with all prior posters. However, beware, many of us with sharks end up with several...

[bigbilly]

Thanks to everyone for the thoughts and suggestions.

As this would be my second car, I'm thinking the american-spec (non-gray-market) M6 is what I'm looking for.

With that said, can anyone see anything in this ebay listing (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=010&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=200175656154&rd=1)that should set off warning bells? I can't understand why an M6 in good mechanical shape would go for this low (buy it now $6500??). :dunno

If anyone can point me in the right direction for the BMWCCA info sheet from "Stan" that jdkirkk mentions, I would appreciate any guidance you can give.

Thanks again for all the ideas.

[Layne]

Wow that looks like a heck of a deal. May not even have to repaint it but for that price you could afford to. Its a perfect time to buy a car, prices are low before christmas. Remember that "rust free" can mean different things, especially coming from Illinois. I would ask for pics of the critical areas just to be sure.

[jeffcfp1]

O.k. Good call. On the M, be aware that it is a loud engine, and can be very loud, no one has mentioned this yet. Can, not will, but can sound like a diesel till fully warmed up. Tolerences much greater than with an M30. Also, mods are more limited than with an M30.

[e24mpwr]

With that said, can anyone see anything in this ebay listing (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=010&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=200175656154&rd=1)that should set off warning bells? I can't understand why an M6 in good mechanical shape would go for this low (buy it now $6500??). :dunno

Hmmm...the tranny and motor are worth a big chunk of that price by themselves.

Frankly, I'm suspicious of any E24 M6 at a bargain-basement price, but I've seen some decent cars go for ridiculously low money. I'll only caution you that a sick M6 can rack up bills even faster than it can go 0-60.

Worth checking out for sure though...

[rlkrlk]

I think it looks not bad for the price.

A concern would be the timing chain rails at that age and mileage, if they are original. You might try and get a compression check if you wanted to seriously look at it as well, and see how much oil it's burning.

Gearboxes and motors do wear out. It could last a good long time as is... or not!

Dash is ugly. ;-)

Cheers,

Ray

[jdkirkk]

Useful M6 information
Stan Simm
800 Chancy Lane
Winston-Salem, NC 27104
336-768-4415
336-768-3336 (Fax)
M6/M5 (U.S.)
M5/M635CSi
(gray-market)

Stan is the man when it comes to good info on these models. He ran an M Register for years in the Roundel and can be contacted at the above address. He still has copies of the 49 newsletters he sent to members of this registry and will send them to you pp for $1 each. If you have an M6 this is information that you absolutely should have; it would be the best $49 you ever spent.

[bigbilly]

I've left a message for Stan, I'm guessing with the holiday weekend he's out and about. From everyone's comments, I'll let this ebay special pass - it's too soon for me to get smart on everything in time. And frankly the price is ridiculous - which raises my concerns. I will find mine in time...

As for mods, etc, I appreciate the heads up on this. My goal would be to get one that is bone stock - or return one to stock. I wouldn't mind fixing one up.

And finally, as for noise, I'm running a 'vert with a CAI and UUC RSC exhaust, combined with a 3.46 diff (up from 2.93). Between the high rpm's and the exhaust, I'm used to loud BMW's. I'm sure an M6's noise level won't be a problem! Thanks for the tip though.

Again - thanks to everyone for the helpful insights. Support from people like you is what makes Bf.c a great resource!

[e24mpwr]

I wouldn't avoid it...but I'd find some local resources to check it out carefully if you're interested. Roadfly has folks all over the US - betting you could get a someone to scope it out.

Like I said - the motor is easily worth $3K+ and the tranny is worth $1500+ by themselves as parts.

[GWL]

I wouldn't avoid it...but I'd find some local resources to check it out carefully if you're interested. Roadfly has folks all over the US - betting you could get a someone to scope it out.

Like I said - the motor is easily worth $3K+ and the tranny is worth $1500+ by themselves as parts. If it was just a little closer to me, I would look & possibly buy, just because it is a good price, if there is not a hidden problem. If it's condition is as it says in the ad, someone is going to make out on the deal. If I was still looking for an /M6, this one would be worth flying up to see. I just noticed that from the looks of the spare tire storage in the trunk, the SLS has already been modified back to none SLS status. (At least the pump & reservoir are gone, you would have to verify that the shocks have been changed out)

[bigbilly]

I wouldn't avoid it...but I'd find some local resources to check it out carefully if you're interested.

Okay, anyone here near Moline, IL willing to help a buddy out?

[e24mpwr]

Okay, anyone here near Moline, IL willing to help a buddy out?

I'd try over at Roadfly - more folks there...sorry if I was unclear.

[bigbilly]

I'd try over at Roadfly - more folks there...sorry if I was unclear.

You weren't unclear, I was just starting with the board I'm a member of first...

But since I just joined - conveniently enough as bigbilly on there too - I'll see what the guys at roadfly can do to help.

Thanks for the tip.

[jeffcfp1]

Loud with reference to engine...ie cold, large tolerences, some say they sound like diesels. Stock exhaust is quiet.

[Sixracer]

I may be able to put some prices behind the M6/M635 talk. I bought a cherry M635 last year, it has 55k on it. I guess I paid upfront for a low mileage car but I kept about 15-20% of my money in my pocket for issues just in case and figure a rather large budget of about $200 for toys and trouble.

I did spend maybe $200 on tune up parts.
Another $350 for and brake pads and front disks.
Had to replace clutch master which was a few hundred at a local shop(owner has a 635)

It already had the brake master replaced and the dual valve spring recall done by previous owner.

A big expense is replacing TRX tires or in my case upgrading to BBS wheels ($2k either way).

I also chose to:
Install Bav Auto chip ($250)
Replace plug wires ($450, probably not worth it)
Bought K&N intake(not installed yet, $200, will need to fab cold air baffle)

So I guess I am in for about $4k in a year, but a lot of it was upgrades or preventative. Could be much worse on a 120k car.

Maybe the issue is 50% the M6 being expensive to maintain and 50% once you own one you want to spend money fixing it up and upgrading it. If you didnt want to sink money into your car you would lease a Camary.

[cmolleur635]

Purchase mine :)

[DaHose]

My M6 has been interesting. I have had it for 2 years and have slowly uncovered all the little things that have been done wrong or just naturally wore out. It started with the simple things as most projects do and now I am in the middle of a complete rear end rebuild and upgrade with parts I am machining myself. I very much agree that if you don't have a pretty high level of mechanical ability, you will find the M6 extremely expensive to own. The funny part is that the labor would pretty much be the same on both, but once you hit the M specific pieces the cost is exponentially higher. Hell, half the stock manifold is $600. Unfortunately, many of the little ancillaries end up costing more because they are built to a higher tolerance. If you have good skills, a good tool collection and space to work, I say jump on the M6. If frequent price premiums of 40% compared to 635 parts is scary, then get a Euro 635. You can tune the hell out of the suspension and it will be great fun to drive.

Jose

[JRanmann]

Personally Billy, if I were you and in the market for an e24 (which is perhaps a better way to ask the same question AND then get better input for your decision making process to come with the same effort. Only you know and can decide what's right for your new stable...If you have the guts and the wisdom to take the vehicle life offers you at the 'restored or as in my case it's completely original, down to the nuts and bolt...and it has a price to match some M sixers... As they all say in Texas, are you man enough to walk your talk and trust your intuition or as some here not old enough to buy what you like and ask question later....

...be advised too that haggling and the use of your energy to fool yourself to believe in the BMW car market with those in the know might be better directed toward (and with) your real (or imagined) faithful wife who's at this moment patiently waiting for you to come in from the garage and in short order your hands are washed and paying attention to her has a serious up-side, just like the Sixer you seek...

Seriously Billy, some women are unnaturally jealous of the Sharks just because they are bored at the slightest provocation and will make that point perfectly clear (if you've really been unlucky in love), then this process really been makec lza very long period of time unless you take immediate action as stated in this simple solution...Of course we here have a good solution for this very common dillemma, and IIRC it's brilliance lies in the details that may also reside most of their life in your new glovebox in the form of the vehicle registration certificate. Simply put, make the car hers at the outset, (or divorce her?) It's vastly easier and saves wear and tear on the relationship...and allows for more time working on the vehicle (as her interests are now also a reflection of yours which lead to you all having to read this very long posting

Mom saying she will fix the food but searching for and maintaing one of these fine automobiles is a choice and a . btw I use mine for my daily driver and I can't think of a better vehicle for that purpose ... alas, I live at the top of a snow covered peak all winter and the roads here are a bit too destructive even to more SUV type vehicles.

My belief and direct experience with owning this particular model had led me to the realization some years ago as to what it does best over the other's. My take on it (it's a visceral feeling) that at the same time my car provides almost everything one could possibly want creature comfort/performace and looks-wise that also for the lucky owner it does it in a very subtle, laid back and almost non-descript sort of way, A style that certainly would fit in perfectly at perhaps a dinner party held in the Southeast perhaps Nashville or Atlanta (with all that Southern charm and friendly ettiquitte we out here in CA gave up along with the long pants) perhaps where the fancier or racier models fit in much better is at the track on a weekend show visit or parked in front of your new lush office, downtown in the building where you own a company that is a leader in medical research and besides, there's the wowing your clients factor and all that jazz..t

My theory of the Art of Motorcycle (and BMW) maintenance has always been to keep the Sixer's well designed sytem's All working... Allof The time ... without too many excuses i've done just that on this one...so


Like a symphony orchestra with all of the insturments and musicians present and adding their own unique contribution. Hence the car rewards me over and over with sweet music, extreme comfort on long mileage trips and performance in many aspects that one can't really come close to in any other BMW model, new or old...These are THAT special, and certainly well worth cherishing and holding onto for a long long time, even if your wife gets a bit jealous!

Also those pre '85 cars are still fairly affordable (although I have mine listed at almost $12k, I know and am obscessed with delivering it to the new owner with it's systems intact and at 100% both cosmetically and mechanically with no odd aftermarket bits whatsover aside from the license plate freams and the handy co-pilot interior iight that in reality should have been a warranty replacement for the weak headlner lamp directly behind your head causing most of the light to go out the back window!

So if what you find out there (and that's not too many) and it's got the right wheels and suspention set up the combo fits you like a new Pendleton shirt at Nordstom then snap it up before you come to your senses and realize that for one brave moment in your life you actually found something worthy of your care and attention. That my friend is getting even more scarce than the e24 itself...

The funny part of it this ownership thing is (and I jokingly sometmes think of it as a religious calling) is that i keep spending time and money on her just out of monthly habit and desire to once again confirm that at one time in my life I did it right, kept it right and passed it on as right and the darned car is still as good (or better) than the day it arrived on the Jersey shore!

Honestly, I am very bonded with this sixer but strangely for reasons other than just driving it or (not at all) showing it off...as it's my personal statement or symbol and expression of my subconscious desire to support all things great left in the world and that includes marvelous engineering and here's it plainly evident in all nice details, etc.

and perhaps a recognition of sorts regarding the expression of all those BMW engineers and Karmann's designers, and for the hours that they all slaved together to bring this idea to life...and in doing so, bringing it to it's perfection for some 12 years over and over again, yes with minor changes over the years but remember doing it all prior to the general use of ATM machines, computers smaller than a large closet not to mention Cell phones and of course pagers and the Internet...It's not surprising that not a one of them was a jet pilot, as their nose was in the details back then and not in the clouds if you will pardon my metaphor.

So, if I weren't buying a house here and now, I would get a loan and build a heed/carpeted garage and keep her there all winter.

You asked I answered as honestly as I could here so do take what you think is relevant and also take a look at my car's details and current state of being.... accessed via the link here:

I assume that you know this already but don't forget that BMW's the numerical designation for the models has more to do with just what numbers are/were still left over after the previous upgrade and mostly relate simply to the size of the engine displacement and also the basic usefulness/purpose/type of the vehicle rather than foster a false belief that a higher number somehow better...in truth is simply more expensive and buying one over the other without specific personal reasons (that only you can identify and address) is very much like refusing to buy a house that you and your partner love in every other way except for the unfortunate fact that it gotten stuck an even numbered address and since that was the case on your previous home, 'you don't want that...no way!

The thing I like most about this last BMW I still own and drive everyday (i've owned (or borrowed) most all of the models and many twice over) there


PS Believe me Billy (and the rest of us here) you are gonna need lots of those insanely new parts from time to time, so do count on that as a sort of regular monthly expense and (perhaps punishment and life's price) for not listening to your mother's insistance over and over that you buy a new Toyota intead....so factor that in with the other incidentals (like a new garage, etc.) and of course then there's all those fancy carwash/detal supplies too...

Good luck and remember...

...just like with drug addiction, it's the hunting for the perfect 'high' (or the perfect wave out here in CA that will decide what Sixer is just right for you...Don't worry as life will take care of all the detail....you hope that you find) that's the most fun...Sadly it's often downhill from that point forward...and that's what we on the board are here for, sort of lemonade stand-ish no doubt but as a group most are good at communicating and all of us here share a love for something that's quickly becoming harder and harder to find in good shape for under $10k which by the way, once over that hump it will repay your investment with many miles of uninterrupted service cuz it's not a hodge podge representation of the last fifteen shade tree mechanics that if true to form usually tinker their project cars into non operation, they rust out and eventally the various componets retrurn to the earth ...and they go worthless,
as they should...here's the URL link to my collectible cars listing....

http://s254.photobucket.com/albums/hh93/JRanmann/?action=view&current=6c1080c0.pbw

Additionally since I was planning to replace the front struts, a few suspension retains and rear shocks (included in the price but if you are willing and able to tighten' up the sway bars and draglinks with fresh rubber bushings although time has grown short and