Loving Every Minute - BMW E46 328i, still only 20..

[McSam]

I'm a very happy boy:



In fact, I have been since May, when I picked this up! Ashamed that I've only just got round to making a thread, but at least it means I have plenty of content for the opening post

A 1999 328i SE, in very high spec and remarkably good condition, came with a fresh MOT (and some VED). 134,000 miles. I've got a sunroof, gorgeous tan leather sports seats, cruise, 6CD changer, parking sensors, automatic climate, headlamp washers.. The list goes on and on, I'd love to know what it cost new! As befits a car owned for eight years by a double-barrelled chap in Buckinghamshire, I have a huge raft of receipts and invoices totalling over ten grand, and the car really does look very well cared for. Anyway, some more photos:









Complete with retro Nokia phone holder :



2793cc straight six, 190bhp, 207lb.ft. This is the later twin-VANOS engine, the M52TUB28. Having done my research, M50 inlet conversions are possible..



I'm still quite capable of looking at it all day long! When I started searching through these cars, and saw one with the tan seats, carpet and headlining paired with a black dashboard and the walnut trim, I knew I couldn't buy one without that interior. I spent my first month or two checking my nearside blindspot an inordinate amount of times for another cheeky glance around inside

I'm coming from a 1996 Audi A4 2.6 SE, and as nice as that car was, it's fuel consumption : power ratio was starting to take the mickey, as was its ride quality. I loved the way it looked but it was time to move on, and honestly, I think the BMW beats it in every major area.

This car handles very neatly indeed and has good body control but, especially on these 205/55R16 tyres, rides exceptionally for something of its size. If you want to get the best out of it you need to give it a damn good revving, but in reality there is plenty of poke wherever you are. The immediacy of the response higher up the rev range is addictive, though!

Surprisingly, quite a good amount of space in the back, too. Though I do sacrifice quite a lot of bootspace, I don't care because that's for a most excellent reason: the diff has to go somewhere!



I really like some of the details, too.

The wings are very sleek, but this wheel-hooding bulge is lovely..


Planning for every eventuality..


Really every single one!




So far, in an alarmingly short space of time, I've done nearly 5000 miles in it! This is a hell of a lot for a student with no commute, but a lot is due to travelling with a race team. I also took it up to Scotland, a 420 mile leg each way, for a week away with my girlfriend and her family. Six and a half hours in a day and neither of us felt a single twinge of discomfort - it turns into an excellent cruiser that also did the whole run on one tank both times! Also proves to be nice and easy to drive, as I let Emily drive for a couple of hours - a bit of a change from her 1.25 Fiesta, but no trouble



Awesome for an engine like that. I keep track of my fuel usage, and the trip is consistently about 2mpg high. 37mpg at 80mph in a thirteen-year-old straight-six saloon?! I could fall in love with it for that alone

Still sitting pretty, 400 miles from home:



To cover the essentials in a nutshell - a bloody brilliant car. Lovely place to sit, and looks great. Rides well but is sharp when pressing on, good steering feedback, wonderfully tail-happy in the wet, and with ever-present power but impressive economy capabilities. When you keep yourself from experiencing the gorgeous howl between 6000 and 6500rpm, that is

And all this for £1750.


Here she sits now, outside my student house with PHer 722Adam's 2.4T S60.. Not bad for two twenty-year-olds!



Actually, I think that could be one of the worst photos I've ever taken, but there you go..


So, looking forward.. The to-do list has boring and interesting stuff.

• Take that phone holder out
• Work out why my radiator fan has forgotten its purpose in this world
• Change the gearbox oil - the thing hates cold mornings
• Try and hunt down a small but evident exhaust manifold leak

• M50 inlet manifold - the M52-engined 328is use a deliberately restricted inlet manifold to keep the power output below an old German tax bracket. Fit one of the freer-flowing OEM ones from an earlier 325i and you see about 210bhp!
• Thinking hard about an exhaust really rather like this one..
• Track day!

Cheers,
Sam

[McSam]

Ah, thanks guys

It is indeed Aston Martins we work with, just at the race meetings themselves - Adam's a mechanic and I do data analysis, both for getting the drivers to go faster and for strategic planning, as the team has six cars and do mostly two-hour races. We run V8 Vantages in the AMOC GT4 Challenge, and yes, it's still awesome even after a whole season!




I really appreciate the comments and I'll definitely be keeping this up to date! I've serviced the car already, some photos to follow, as well as doing a very entertaining run with another PHer but I felt my first post was getting on a bit! She's really in amazing condition, I honestly think I have one of the best 328is in the country, certainly a class above any others that were for sale at the time.

Insurance is no major problem, actually. I'm always stunned by how much it costs for other people my age - I swapped from the Audi to this halfway through the policy so never paid the full premium, but it would have been around £1000. At renewal, I'll have just turned 21 and expect more like £750. I have a good postcode and a clean record, and have always been insured as a main driver, so perhaps that's where it comes from. I'm glad it enables things like this, though!


And cheers, Sandy, but..

BorkFactor said:

Black leather with walnut inserts is the way to go though

Nah

[McSam]

Cheers Carter! Hope you enjoy yours just as much

Andy665 said:

The Esenmann exhaust is not cheap but quality is superb, have one on my 328 Sport

Hmmmm I've thought of Eisenmann before, but on V8s and V10s they often seem a tad too aggressive. Have you got a video of yours? Would love to see what it's like on this engine!

[McSam]

Thanks guys! Living the dream it really is. The versatility of the car is almost the best bit at the moment.. I can take my grandparents out for dinner in leather-lined luxury, or I can go seriously quick on a great road with a very well-balanced chassis.

Naturally I'm now biased, but when I was looking I always thought the pre-facelift cars looked nicer. There's something too "smiley" about the newer headlights, perhaps proven by them never being used on M3s!

Sparks, I saw some photos of your car in Sandy's thread, very nice I considered E39s myself, but as I don't need the space I thought I'd save myself the weight and potential costs. Plus if I did it I would be compelled to get a V8 one

Andy665 said:

I'm 45 so aggressive is not the note I'm looking for, its deep and since doing the M50 inlet manifold conversion I now have some pops and bangs on the overrun, no noisier than standard when at a constant speed

Hmmmm, that sounds lovely.. Just what I'm after. Is yours an E36? And do Eisenmann just do the one system for this car? I'll get myself on YouTube and see if I can find an example.

[McSam]

Thanks Andy - they do indeed have a video on there, and it's nice too, exactly the sort of thing I'm looking for. At £660, though, it's a bit steep - I presume that's from the cat back, not including the manifolds as well? I'll bear them strongly in mind when the time comes

I know exactly what you mean about the arches, Evangelion, I really like it for that. It's a good job, because the Audi filled its arches perfectly, but then lowered on 18" wheels it would do. This does it completely standard, and I really like it! It does have the factory sports suspension option too.

danjama said:

Lovely car and good write up.

Sorry to go a bit off topic, and I hope this isn't rude, but what steps did you follow to find yourself working with Astons on track? Would love to do similar.

Thanks! Not rude in the slightest, worry not but sadly, as with everything in motorsport, it's down to who you know. This one I came upon quite by chance, through someone I know on my university course. It's turned out that, thanks to the experience I already had proving useful, the team are more than happy to keep me on - but they're not short of staff now, I'm afraid!



Back to the car, a new job has presented itself - I had a light but persistent scraping sound coming from what we identified as the rear left brake disc. I thought I might have picked up a stone or something, and it didn't seem to affect the braking performance at all - though, at the rear I wouldn't expect it to. Today we jacked her up and got the wheel off, and the mystery was immediately solved:



The rusty disc surface is purely down to the car having been washed, but it's looking decidedly shaky at the edges anyway, and the pad is clearly down to the backing plate. It's started to carve into the disc at the outside, hence the noise. The other side is well worn, but not as far, explaining why the noise was only from the left side. Pads and discs are being changed this week. Thankfully I can get Bosch ones for £65, despite them being vented discs at the rear! Someone engineered this properly

[McSam]

Thanks Daniel

So, having discovered that my rear brakes really weren't in the decent condition they looked through the (narrow, in my defence!) alloy spokes, work was due:



These ought to do the trick



Hmmm. Yes. I think it's perfectly possible that these have been there for the full thirteen years! In particular, the caliper guide bracket nuts took some cracking off.

The wear sensor (thankfully only one, on the right side) was trickier than it could have been! It's attached to a cable about three feet long, which routes all the way along the subframe, through a tiny gap, and into a little control box under the rear door. Cue much contortionist wriggling on the deck to get to it! We didn't break any clips, though, and the new one went in just fine, so shan't complain



Happily, the handbrake shoes within look fine. It really wasn't as easy as going from one photo to another to get the discs off the shoes were, as you could imagine, rather fond of them after 13 years and didn't want to let go. Much wobbling, shaking and prising later saw the left disc come off, which then entered service as a hammer to remove the right one, which really was seized in place. We got there in the end.. I was baffled as to how the right-hand disc could still be wedged when it was hanging 90% off the hub...

..but this was explained when it came free and took the handbrake shoes with it



Analysis time. Mmmm. Haven't seen pads like that for a while! Scraping noise duly explained.. For the sake of comparison:



So, finally..







Excellently placed branding there! Now she brakes smoothly and firmly, but most importantly silently. Took the two of us around two hours to do, including farting about jacking the car, struggling with discs, taking photos, etc. Not bad. Parts were £70 in total, so very pleased with the result!

Cheers Adam

[McSam]

722Adam said:

No problem mate

You just wait til we do the handbrake shoes on the Volvo

I can barely sleep with the excitement

Walsh, that's a serious consideration glad to hear it works nicely.. Certainly when I do the M50 inlet manifold, that would be happening! Maybe sooner.. Is yours a simple K&N type cone, or a particular brand? I've considered the classic DaveF job, but also something like this:

{image removed due to malware on external site}

Yum..

[McSam]

walsh said:

Mine is a K&N, properly installed to, with the feed pipe going through the wing.

Probably provides some sort of increased response. I am skeptical of any power increase, but under load 4500rpm onward, it sounds close to an M3 CSL. Doesn't do the mid range snarl thing they do, but the top end makes a fantastic racket.

Davef is widely regarded to be the best, looks good, but I wouldn't change mine for any. doesnt bark until you want to play, even under full load.

Hmmmmm.. Sounds like exactly what I'm looking for! I'd love to get more of a howl at the top end, but without knackering the chauffeurability. I'm gonna have to start looking, I think, this is an exciting prospect and happily, when compared to playing with the exhaust setup, much cheaper and easier to reverse. Not sure how much I should be paying, but I'll look into it.

Cheers Sandy - wear sensor wasn't hard as such, just a little fiddly, and the one I was supplied had one pin marginally too big to fit the socket, and it was getting dark, and the car wasn't really high enough to access it... etc etc, I was predisposed against it

[McSam]

Thanks again for the info, Walsh. Is yours a Gen II 57i, then, for those prices? I've found the first-gen 57i kits for around £70 on eBay, which is a real bargain. These still have proper inlet pipes too.

I really like the look of the Simota carbon ones - have you seen facing into one? Looks like a turbine! - but do agree their positioning is daft.. I think a cone filter further back would work better, despite lack of heat shielding.

I had considered oiled filter vs MAF, and am not yet sure whether it's likely to cause a problem.

2 Wycked said:

McSam said:

*Work out why my radiator fan has forgotten its purpose in this world

I haven't read every word in this thread but I had the same problem on my E36 325i and it's likely as not going to be the viscous fan coupling; it causes the death (through overheating) of many an M50/52 engine.

Further to that, well done on owning a decent car at 20 - I bought my 850 T5 when I was 19 and haven't looked back since. The only reason my current car is so darned sensible is because I do such a huge amount of miles.

No more has been mentioned about the fan yet! Thanks for the heads-up, although, while I know all M52s are supposed to have a viscous coupling...... Mine appears not to. I'll get a photo up next time I remember.

Thanks some of your back catalogue is very good too!

[McSam]

I think an update is in order.. I finally gave in to the need for more induction noise, I can tell there's a lovely-sounding engine in there but it needs to be given proper voice.

So..



I've yet to get the intake piping sorted out properly, apparently it wasn't designed for E46 sixes, because K&N want it routed down to underneath the front bumper - I have a full undertray! Instead, my plan is to cut a fitted hole into the brake ducting and run it through there. Should work well and look professional

A little bit of aural description..

£65 well spent, I think!

[McSam]

Yep, also on the list, as soon as I can think of an effective method. Thankfully I don't do a lot of town running, so don't expect heat soak to be a major problem, though I am considering moving the exterior temperature sensor to somewhere useful under the bonnet to see how it varies in normal running!

You can see the end of the kidney grille intake in the bottom of that photo, I am going to use that, there's a black connecting hose that runs to the original airbox but is about 5mm too long to be used with this filter. I'll adapt that too, and then I'll be making use of both that and the ducting from beneath

[McSam]

I wasn't sure what the limit might be but did think a temperature sensor of some sort under there could be a neat solution. It's not exactly a race car, but it'd be interesting!

I haven't looked into diagnostic systems for this car yet, I don't know what's available - do you have software for your own E46?

[McSam]

Cheers petrolveins, I'll have a look! Definitely sounds like the sort of thing that would appeal to me and I'm surprised you can get so much data from it. Excellent.

I'm at Loughborough, 3black

[McSam]

Ah, I did check your profile but forgot that while some E46s were made in '98, they weren't coupes, and the model years started in '99! Fool. I'm gonna have a read of your thread now though, looks like a decent example!

Thanks for the tip on the software, too, I'll look that up when I have more free time. Though if you decide you want to sell on your E46 cable, drop me a message

[McSam]

After over a year I think it's about time I updated this thread!

I'll go through what I've spent/done up to now:


Airbag sytem
The car has had an intermittent airbag warning light, which is apparently very common.. Two things can do it, one being the passenger occupancy sensor (essentially a pressure-sensitive mat in the front passenger seat which checks if anyone's there and arms their airbags if there is), and the other a phantom fault in the airbag ECU. So I got a code reader, which told me the passenger occupancy sensor was faulty, and also gave a fault for "right side airbag firing circuit".

I reset it just to see if it stayed off, but alas not

The occupancy sensor is actually a pretty expensive thing to replace, but an alternative was at hand - a small resistor plug which permanently gives the correct "passenger present" signal. This was a whole £7.43 delivered, and when installed resolved that fault code.

Unforunately, while the driver's side airbag code would go away, it would always come back within a week or so. I decided to take a look:



Door card actually comes off quite easily, but more importantly it went back on again properly too!



Voila driver's side airbag. Everything looked perfect, all wiring, harnesses and connections looked brand new. If there really was a fault, it had to be in hidden wiring or within the ECU itself. I'd read about people replacing the airbag ECU and still not stopping the fault coming back occasionally, so I decided it was going to stay.

Currently, the warning light's off and has been for three or four weeks. Occasionally it comes back, and I clear it again. There's plainly no fault in the system while the light isn't on, so I'm happy enough that everything will work as intended should it be required.


Central locking / GM5 module
I started to get strange central locking issues, where the car would always lock OK, but not necessarily unlock at first time of asking. You could open the driver's door with the key when this happened, but none of the others - not even from the inside! This started out very occasional but became more regular until it was clear a complete failure was around the corner.

Some research showed there's a general "body control" module (GM5) that's responsible for this type of thing, quite a common failure, relays in it start to suffer. A new one is something like £200 and then needs coding to your car by BMW, which didn't sound ideal, but thankfully there are many out there who will recondition them, so I removed it and got it posted.

GM5 not too bad to get to, the flat grey box:


You can actually drive the car without it, but you'll have no alarm/immobiliser/central locking, electric windows or, more worryingly in March, windscreen wipers It came back repaired and working perfectly, no problems since. Not bad for £45!


Front Brakes
Nothing major. The pads were actually alright, but the discs were pretty done for, so replaced the lot with Bosch parts. These came off far easier than the rears covered earlier in the thread!

Nasty, who can tell how long those were on there:


Not so bad, but foolish to re-use on new discs:


Trusty assistant finishing off his side:



Cooling System
Reckon I did quite well to make it this far without having to write about the cooling system. During the car's MOT in May 2013, a negligent tester let the car overheat on the ramps. In fact, it overheated so severely the pressure punched right through the expansion tank:



The radiator didn't look too clever either, shown here removed with its dead fan:



Really shouldn't be in that half-moon kinda shape at the bottom.. Apparently, the cooling system is semi-designed to fail by splitting the expansion tank like this. Rather there than the head gasket, anyway.. New radiator in:



New fan was duly fitted. If you have an electric fan that's failed, honestly, it's hilariously easy to replace - one Torx screw, four expanding screws, a wiring harness (all at the top end), and it just lifts out! With that done, the cooling system was perfect, even in 25'C traffic, and the car seemed to have suffered no ill effects.



Until...

I had a severe overheating problem on my way to work in December. Initially I thought the heater wasn't warming up as quick as it should, as within a mile I usually have some warmth. Then as the car reached temperature at the normal sort of point of the journey, the temp kept rising, extremely quickly and even when off load at 50mph. Clearly, no coolant flow at all. Stopped, let her cool, limped home and a couple of days of thought and testing later I diagnosed a sticking-closed thermostat.

This struck me as really, really unlikely - never having heard of one doing so, and on a car where the water pump is a known weak point - but it was the only thing that fitted all the symptoms. The 'stat comes as a complete unit:



£40 for a good replacement. It's nice and easy to get to, unlike the last one I did on an Audi V6 which required the whole front of the car off! In fact, you only need to get the inlet duct and radiator fan out of the way and it's simple. Twenty minute job. At least, it would be if the two of the four bolts weren't corroded down to little nipples of rust.. Much swearing, judicious vicegrip use and some gentle persuasion later, the bugger was free. New one in, and the problem was solved, the coolant flowed properly again. Major relief.

Presumably due to the temperatures reached in this particular failure, the radiator top hose developed a very fine split that meant it would dump some coolant when hot, so replaced that with a nice Febi one, and all was well in the world again.



Compression Test
A short time after this overheating problem I realised the car seemed to be using a hell of a lot more fuel. My commute is especially bad for it (10 miles with 14 roundabouts each way..) and the cold wouldn't have helped, but nevertheless it seemed excessive, around 25mpg did not impress me. I wasn't sure whether my mind was convincing me of a loss of power or not, but it did seem to be lacking something. I also had a strange tapping/popping sort of noise at idle, which sounded to me about the right frequency to be one cylinder on its power stroke (~4 pops per second). I started to doubt the integrity of the head gasket. So I bought myself a compression tester, and just this morning had a go.

Most of the plugs were looking pretty good:



But number 3 cylinder's plug wasn't even finger tight, in fact it was about half a turn loose. And it (and its coil) didn't look so happy:





Proceeded with the test, and here are my results, vs. a minimum of 142-156psi for the M52 engine and a maximum permissible variation of 7psi:

No. 1 - 192psi
No. 2 - 193psi
No. 3 - 191psi
No. 4 - 192psi
No. 5 - 191psi
No. 6 - 195psi

That looks great to me, which has pleased me no end and on firing back up afterwards, the idle noise had disappeared, and she seems considerably smoother.

If you're reading this and fancy a compression test on your E46, I can easily post a how-to, but the important points are to diable the fuel system (I pulled the fuel pump fuse (#53) with the car running and let it empty the lines until it coughed and stopped), and uniquely to the E46 remove the DME relay. This disables the ignition system, which is sensible enough, but you must do so by removing this relay (sky-blue, in the box in the top right of the engine bay). If you don't, cranking the car repeatedly with no fuel supply and the coils disconnected can apparently cause serious damage to electronic control modules. Like this, I was absolutely fine and had no engine lights on restart.




Well, that turned into a mega long post.. Congratulations on making it to the bottom

Next on the list is another service, oil, filters and possibly coolant too. After that, I'm considering reconditioning the VANOS - the seals perish, and as a result the engine can't adapt the timing quickly enough as you accelerate through the lower ranges. That's kinda what the car spends its life doing on my commute, so if they're knackered, I'd be losing a lot of power, response and fuel to it. Improvements of 5mpg are not unheard of, so seems worth looking at!

More photos of the car, rather than just the bits of it that are broken, to come soon

[McSam]

I'm not sure about the rear end in general - I am detecting a slight bit of uncertainty in its response to sudden inputs, but most of the time it's fine. I can't be sure whether it's a change in my car, or the fact that I've been evaluating a lot of brand-new ones recently and its usual characteristic might stand out in contrast!

I'll take a good look around when I service it. It's unfortunate that I'm only really using the car for commuting at the moment, little chance to stretch her legs, maybe I should plan a bit of a drive soon..

[McSam]

Cheers Sav!

Service time today. This is actually the first car I've kept long enough for it to need a second service, that made me realise I must rather like it

Not a huge amount of space to work in here, but it'll do:




Sump nut came off nicely, it was on tight but not overtight. Seeing as I'm the one who put it there, I was glad about that! The access hatch in the undertray is perfect, no idea why other manufacturers design undertrays to be fully removed for oil changes. Equally excellent is the oil filter housing on the front & top of the engine bay.




I'd noticed during the compression test last month that the cabin filter was well buggered, so I changed that while the oil was draining. This surprised me after only 18 months and 15k:



Old vs new, bloody hell..




The oil draining's down to a trickle by now, but time enough to get the K&N open air filter off. I've decided to revert back to the standard airbox for now - in my daily commute there's little benefit to having a beautifully howling top end, and until I get my fabricated heatshield in, it's going to be suffering a lot of soak from the engine. So back to OEM we go..







This is rather nicer. Yes, some of the resonant urge in the midrange is gone and the top end is a shade muted, but in normal use it's quieter and doesn't make the annoying faint hiss that the open filter generates on part load.

Next up, front end auxiliary drive belts. Yes, plural, I didn't realise this before looking but it turns out BMW decided to have a common belt for all M52s to power the water pump, alternator and PAS pump, and then add an extended pulley and another belt for the air con where fitted, which is a new one on me. Here they be:



I faced these with some trepidation, having no idea how long they'd been on, but it turns out BMW saw fit to put little plastic covers over the tensioners, so they were in perfect nick, and with a T50 bit on my 3/8 ratchet they moved easily. The lower left one, for the air con, was dead easy and I was really pleased with myself.. until I realised the longer one could only come off past it, so it needed to come off again

The A/C belt (left) looked OK, but the main one (right) was rather more tired and I was very glad to be changing it.



Oil filter housing cleaned up and new O-ring and filter installed, new sump washer swapped in (though the old one looked good so kept that in the toolbox), torqued up, back on the deck, and 6.5 litres later...



She's ready to go!



Drove beautifully, and idles noticeably quieter with the belts replaced. I think various coolant spillages and years of ageing had them slipping quite regularly. Happy with my Sunday's work, anyhow! Researching changing the VANOS seals as my next job.

Edited by McSam on Sunday 2nd February 18:15

[McSam]

St. Anger said:

Holy thread resurrection! I'm looking at buying one of these next week, how are you getting on with it?

Ah, I fear I'm too late! Sorry I didn't notice your reply, did you take the plunge in the end? I hope so, because I still have nothing but praise for this car, no competition at this price point.

If you're still looking, I can give plenty of buying advice, having had most of the common issues by now

[McSam]

Heh, very nice - I find myself in a similar situation now, but with two 328is instead! The stiff, hard E36 for tracks and the comparatively lovely, soft and quiet E46 for road

A minor update - it's often mentioned on here that you should only ever fit original BMW thermostats, with these engines being very sensitive to overheating and the cooling systems in general being a weak point. You know what? They're right.

I fitted a Cirocli thermostat from Euro Car Parts as a matter of emergency when mine stuck closed back in November, and you know what, it's already failed. It became unreliable and then stuck open completely within about 500 miles, obviously right before going on a 1200 mile trip to and around Scotland, why not.. A proper replacement is now installed. Thanks to this car having (oddly, by all accounts) an electric radiator fan rather than a viscous coupling, it was a pretty quick job and all seems well again.

Here's some photos from a great run alongside BorkFactor's 328i. We stopped off at Fyvie Castle for a look, and did this rather wonderful route. It's always a pleasure to show this car some good roads, it still performs admirably!

[McSam]

dazz1871part2 said:

I may be wrong (sure I'm not) but the m50 mani mod is only for e36. U need m50 mani from 2.5 and fit it to 2.8. They don't fit e46. Oh and I know on e36 the Thermostat housing splints so need a metal one so with the water pump and they can go, not sure of its same with e46

You're half right about the inlet manifolds - the M50 part doesn't marry up to E46 M52TUB28s very well, the twin VANOS design is quite different. What you can do, however, is fit the manifold from the M54 in a 330i, this fits OK with a throttle body adapter plate and gives the same (if not better) results. Now I have my track toy E36 as well I don't feel too much need for more power but that would be on the list!

The whole cooling system is a bit dodgy on E46 too, but mine has had everything except the water pump and lower radiator hose replaced. All E46 M52s have plastic thermostat housings which seem pretty robust - I haven't managed to break any of the three I've handled - but you can't remove the actual thermostat from the housing without breaking it, so you have to replace the whole lot which is annoying. My E36 is an aluminum housing