New member and owner looking for advice with project car!

[Chest Rockwell]

Quick story - I'm a motorcycle guy my whole life. My current ride is a BMW K1300s, 175HP comfortable rocket sled. When I was young I learned car on a stick but then as life evolved I ended up with automatics and boring cars. I decided finally to go back to my driving roots and sell my 2007 Honda Accord auto (yea I know but it was a smart buy at the time) and jumped on a 2003 330i ZHP after doing research for a great driver's car that's affordable. I've always loved the look of the E46 platform and after reading about how awesome a platform it was (probably one of the best BMW has made?) I was sold. As much as I wanted an M3 I still have to think about practicality with a family so I opted for the ZHP sedan. I’ve had it about a week and I love it. Titanium with black leather, silver trim, loaded. Excellent condition with 135K on the odometer. However it doesn't really have much in the way of history so I'd like to restomod her with the help of this forum. I have done searches but some of these threads are a bit old so my questions are to just make sure I have the newest info - I can do basic wrenching and have a decent tool set. I'd like to do as much as I can and learn with this car because the only one who cares about your ride is you...I've been screwed by half ass work by dealers and mechanics far too many times. I can do much more work on bikes but that's a little different animal however I do know from experience that power is nothing without control so suspension/steering/proper alignment/camber/tires are definitely on my more important list. Like most people I’m on a budget so I’d like to have a good mix of performance/price. Right now I have about 2K I can spend on her and then I’ll do another round when I have some more money saved.
So onward to my plans/questions…

Please let me know if these need to be re-prioritized and if there is anything that should be grouped together to do while stuff is accessible:

1) Reinforce rear subframe. It’s been inspected and has no cracks as of now. What’s the latest on the best way – I’ve seen the bar method and the plate method. Doing a quick look at the E46fanatics DIY this looks like something I don’t want to do and should take it to a shop...
2) Cooling system overhaul (expansion tank/hoses/WP/T-stat). Do this myself? Also should upgrade the T-stat right…
3) Break fluid flush, replace lines with SS, new pads & rotors. I’d like to try and do this myself…a lot of opinions on here so not sure which way to go.
4) VANOS seals & ant-rattle kit. It was checked out and I was told no issues and I don’t hear a rattle. Put this off for a bit? And is this something I should probably farm out? How would I know if there’s any issues with the VANOS…
5) Pulleys (water pump, idler, A/C) w/ belts. I want to go with an underdrive set and also upgrade water pulley to aluminum. Do this myself I think? This is something I need to do soon as they look worn.
6) Change diff & tranny fluid and power steering fluid flush. Should this be done just to be safe since there’s not much history
7) New final stage resistor (FSR). Necessary?
8) Check oil filter housing gasket & engine valve cover gasket – what exactly should I look for? This looks like something I want a shop to replace if necessary
9) New pre-cat O2 sensors. Necessary?
10) New DISA valve. Necessary? They are expensive now (German Automotive Solutions) but you can rebuild but that looks like a bitch…is there a way to check?
11) New spark plugs. Do this myself. Should I replace coils as well?
12) Suspension replaced w/ coilovers. Control arms, endlinks, CAB’s, bushings, sway bars, brace. I do aggressive street driving however I also drive on some really crappy city roads so I definitely want a compromise between control and comfort. Not sure where to go on this since there’s so many people with different opinions…it’s like an oil thread.

Most of this list I compiled from the maintenance section of this website. There’s a lot of other cosmetic things I’m not going to bother listing since I can do them all myself. Once the above list is done I’d like to focus on performance. I know you can’t get anything substantial unless you add a turbo or supercharger but I’d like to make sure I’m getting as much as I can from the engine. The underdrive pulleys seem like a no brainer, cold air intake looks like it’s not worth the money. I’ve read you can have the ECU flashed so that seems like it’s worth it. Exhaust seems like too much money for too little gain unless I can find a used one on eBay or somewhere.
I really appreciate forums they are a great help – I’ve spend many hours on motorcycle forums that have taught me a lot and saved me a ton of time (and money) so thanks in advance.
And lastly, if anyone has recommendations of a god indie BMW shop in the Atlanta area that would be great. If any of you live near Atlanta and want to come help me with the project I’ll buy you a steak dinner at the finest restaurant…

Cheers

David

[san]

Welcome David!

IMO
1. Cooling system and can couple with pulleys
2. Change diff and tranny fluids. Easy and won't take much time, so just know it off.
3. Suspension components
4. Brakes. If they need to be replaced immediately then move to 2.
5. DISA, change it even if it's working well, the screw(bolt?) can fall off and enter the combustion chamber.

Spark plugs, I don't think is necessary to be replaced unless they haven't been since it left the factory

O2 sensor don't bother unless it is throwing a code

Ofhg and vcg check for leaks and can replace the vcg while replacing spark plugs and /or vanos

Not sure about fsr.

Coming to subframe (RACP) cracks, it's not an immediate concern if it's been checked and it's good. You can get it reinforced if you have the budget and for piece of mind but I don't think it should be the first priority. Also google Vince Bar for e46, a few people think that it's a better solution than welding plates. I haven't researched about it to know a lot.






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[BMWCurves]

Again, welcome and congrats on your purchase, David! I'm glad to hear you're enjoying the car so far.

In terms of repairs, I pretty much agree with San, but I'll go over the points in my own mind. N.B. I did repairs on my car when it had about 50k miles so maintenance was often as a result of age of the parts rather than pure mileage. Many items I haven't touched though that are more mileage related (VANOS, DISA valve, CCV, tie rods, etc). I'll include a parts list that I used on my car after my summary below. I've done the vast majority of this work myself and I came from a very novice understanding of DIY wrenching, so if you have the tools, time, and space, you can do most of this yourself as well.

• Cooling system - This is a priority, and is easy to do yourself. It's a known weak point in the M54 engine. I personally replaced as many components as possible including the radiator because I rather have all the components new than have to go in and drain/bleed the coolant each time an individual part when it needs to be replaced. Many people don't replace the radiator and it might not be as big an issue on the M54, but for the M62 V8 from the E39 540i that my father drove, the plastic radiator inlets broke like clockwork every six years. So I felt I'd rather be safer than sorry. All parts with a radiator are probably $400-500.
• Belts/pulleys - If you have the cooling system apart, it makes life easier to do the pulleys and belts while you are there. Relatively cheap and easy to do. Numerous guides (if you go to my project thread by clicking on my sig picture, you can find links to all the guides I used DIYing my repairs). Going to a metal water pump pulley is a smart idea. I wish I had done it.
• Fluids - Change them all, IMO. It's cheap insurance and you know when you replaced everything and you know exactly what is in there.
  The clutch and brake lines are connected so they all use brake fluid. There is some debate whether you should use low viscosity (LV) fluid for proper ABS function, but numerous people use non-LV DOT4 fluids like ATE type 200, Pentosin, etc and it seems to work just fine. I personally use Pentosin LV DOT4, but if I were to track the car I'd flush the system with something with a higher boiling point.
  Transmission and differential fluids are cheap and easy insurance against wear. I used Red Line MTL for the transmission and Red Line 75W-90 for the differential. Other people use different oils, just take a look around and see what there is that fit your preferences.
  Engine oil is easy enough to do. BMW recommends 5W-30, but people use a myriad of different oils such as Mobil1 0W-40. Be sure to replace the small green rubber o-ring in the housing every other oil change (listed below).
  Power steering fluid is a commonly overlooked fluid. I used Red Line D4 ATF. I had my mechanic do this since he did a proper flush by releasing it at a physical low point in the system rather than the common turkey baster method which I think isn't sufficient. Many people think this is enough so do what you think is appropriate.
• Valve cover gasket (VCG)/oil filter housing gasket (OFHG): I haven't had to replace either of these but I plan to do them myself since my VCG is leaking ever so slightly. Neither one is supposed to be very difficult to do on your own. Get a Viton OFHG (linked below). For the VCG, look for burnt oil residue on the fins above the exhaust manifold. If you are facing the car with the hood open, look to the left side of the engine and down below the plastic valve cover. You'll see some fins and they'll often have burnt oil residue on them which is a common sign of a leaking VCG. OFHG will have oil around it, I presume. As I said, I've never had to deal with it.
• Other general items Spark plugs (depending on when they were last replaced, cheap replace regardless), air filters (cabin and intake). Fuel filter if it hasn't been done, and replace the soft hoses with it (kits can be purchased, linked below).
• Suspension: I don't have much experience with coilovers but many people swear by them. If the suspension hasn't been touched, then your bushings and shocks are very worn. I personally wanted an "OEM+" feel for my car i.e. improved performance that maintained or improved comfort that also addressed known issues of front strut tower mushrooming and the rear shock mounts. Basically it was replacing fluid filled bushings with OEM solid rubber bushings and replacing shocks with Koni Sport/Yellow shocks (adjustable) and replacing other ancillary components. You can read about my refresh that a handful of members have followed/duplicated with positive reviews here: http://www.zhpmafia.com/forums/showt...miles-10-years
• Brakes: Do them as needed. The regular old BMW solid brake rotors are fine, some people prefer slotted or drilled rotors for other reasons. I personally have BMW Performance drilled brake rotors (since discontinued and overly priced) because they shaved about 3 lbs/1 lb front/rear in unsprung weight and supposedly have improved wet weather performance which is perfect for the PacNW. The BMW pads produce a lot of dust so many people opt for different brake pads that are the same price or often cheaper than the BMW pads. Aftermarket pads will produce different pedal feel but you can get improved performance with less dust production. I use Hawk HPS 5.0+ pads and I have liked them so far. As far as stainless steel brake lines, I'd go for it. I'd also go for a stainless steel clutch line since the clutch line shares the same fluid reservoir as the brake lines. I purchased StopTech SS lines from Turner Motorsport and have a SS clutch line from UUC.
• VANOS - I don't think you need to really touch the VANOS until there are issues, but other people would know a lot more about it than me. It is a moderate DIY job as far as I can tell (fair amount of bench work), but not that difficult supposedly.
• DISA - Rebuild is supposed to be easy. You can remove and inspect the DISA flap and see if it springs back or has any play. I plan to do it for my car at 55k miles sometime soon. Get a kit from German Auto Solutions (G.A.S.).
• Battery - The electrical system is sensitive to old batteries. Mine made it 10 years before it started causing weird popping sounds in the speakers. Worth replacing if it is old.
• Vacuum leaks - tougher to chase down, but often the upper or lower intake boots will have cracks in them that can cause a vacuum leak. Easy enough to replace if they do have cracks in them. Buy an extra F-connector if you are replacing them, I hear they're easy to break in the process.

As for some of the other things you mentioned, I'm not sure I'd go there.

• Subframe cracking isn't as big of an issue in late model year E46s. Other members like Peter (username Slater) will tell you that it is inevitable that the subframe will crack and he may be right. It's a matter of risk assessment but I don't plan on doing any reinforcement anytime soon. Peter's much more knowledgeable on the subject, so have a discussion with him.
• Final stage resistor - This is low priority in my book. Really only replace it when your AC/fan starts acting all wonky, not as preventative maintenance. I replaced it in my father's E39 540i after 15 years and the AC started acting up.
• Pre-cat O₂ sensors - I wouldn't worry about this unless your car is giving some sort of engine code. Others would know more, but I think the mileage is appropriate for them to start to be worn.
• Coil packs - same thing, if they're working fine and not throwing codes or causing misfires, no need to replace them.

As for your modifications/performance list:

• Underdrive pulleys - common option. I go back and forth on getting a set. The upside is most of them are metal which is an improvement over some plastic components. Some members have reported noticeable power gains while others said they felt little to nothing. It's subjective but I'd believe there is some power to be gained there.
• ECU tune - these can't really do all that much on a NA engine. I have the Conforti Shark Injector. I think it gave me some top end power but what I noticed more was an improved throttle response. I got mine on sale but I would not pay the full $350 it costs. There is a quasi-affiliate here for EuroCharged that does a ZHP-specific tune that many are pleased with. Just don't expect much from it.
• "Cold" air intakes - not much power to be gained here, maybe 1-2 hp max. BMW claimed their Performance intake only provided an additional 3 hp. It's basically for the noise. I've had the BMW Performance intake which I believe did add some top end power but who knows how real it is. I've also had the GruppeM intake which has an intoxicating induction noise. You basically buy them for the noise, not the power.
• Exhaust - Similar to changing intakes, you really do it for the sound. There might be a few hp to be gained from a freer flowing catback system, but the real ticket is getting headers, which is its own can of worms. You'd have to talk to someone with more insight. While the stock ZHP exhaust sounds good and is refined/reserved, I am looking forward to installing my used UUC TSE3 which many think is the best exhaust for our cars.

Some other modifications that you might consider:

• Clutch Delay Valve (CDV) Delete - Remove the clutch delay valve for improved clutch pedal engagement feel.
• New tires - Tires make a lot of difference in how your car handles. Dedicated summer tires can really make the car handle better
• Different wheels - the stock Style 135 wheels are really beautiful wheels and are a distinct design of the ZHP. However, they weigh a ton, close to 28-29 lbs a piece. Lighter wheels will improve not only ride quality and handling through less unsprung weight, but will also improve acceleration performance to a small degree.
• Short shift kit - there are several kits. I have the UUC Evo3 short shift kit and while it is very expensive (stupidly so), it is a very good piece of kit. Other members have opted for BMW's performance shifter or a shifter out of a 330d. There are many options.
• E46 M3 Transmission and Engine Mounts - Should make the driveline a bit stiffer for a better response and shifting feel.
• M3 front seats - I have a coupe so they're plug and play but can be swapped out in a sedan easily enough. I love them, they have great lateral support through bigger side bolsters and are more comfortable in my mind than the seats that came in the ZHP.
• New final ratio differential or LSD - The stock manual transmission comes with a 3.07 final ratio, but many people opt for a 3.38 or 3.46 ratio to give the car a little more acceleration. Many members have opted for a limited slip differential as well, a feature that should have been fitted to the car from the factory.
• Lighter flywheel - Not my first choice and not something I ever plan to do, but there are performance benefits
• Strut braces - front and rear. Not sure they do a whole lot in our cars, but the E46 M3 had a front one from the factory.

[BMWCurves]

My conservative replacement intervals for fluids and some parts. Many might disagree, so adjust as you feel accordingly:

• Fluids - Coolant (every 2 years), brake fluid (every year or before any track event), power steering fluid (every 30k miles or ~5 years), transmission fluid (30k miles), differential fluid (30k miles), motor oil (5k or 1 year). Again, these are guidelines. Many people will say you can go 50-80k miles without changing differential or transmission fluid, but to me it's cheap maintenance, like $30 total to keep your car's internals running smoothly.
• Belts: every 30k miles
• Pulleys: every 50k miles
• Fuel filter: Every 50k miles
• Intake filter: every 30k miles
• Cabin air filter: every 30k miles
• Cooling system: 60-80k miles or until you see signs of wear such as a sticking thermostat or a bulging hose.
• Spark plugs: every 60k miles or so

PARTS:
Suspension:I'll toss a link in to my suspension refresh thread again, here: http://www.zhpmafia.com/forums/showt...miles-10-years

Cooling System:

• Upper (17127510952) and lower (11531436408) radiator hoses
• Wahler thermostat (OEM) (11537509227)
• Graf or BMW water pump (OEM) (11517509985): the concern used to be the plastic impeller would disintegrate but they updated the design a while ago so I think any OEM manufacturer should be okay.
• Auxiliary fan switch / coolant temperature sensor (OEM) (13621433077)
• Expansion tank (17117573781)
• BMW coolant level sensor (17137553919)
• BMW shroud clips (17111712963): they can break easily and they're cheap at $0.69 a piece. Get a couple.
• BMW coolant (82141467704)
• Expansion tank cap (BMW or Rein, which is $9 cheaper): you have two options. The standard E46 cap (17117639022) is rated to 2.0 bar before it vents. Some people believe that the high pressure is what leads to premature expansion tank/cooling system failure, so they opt for the E30 expansion tank cap (17137639023) which has the same fitment as the E46 but is rated to 1.4 bar instead of 2.0. You could also continue to use your current cap. I'm not quite sure why people replace them, maybe they're considered an age/wear item. Also consider German Auto Solution's 1.2 bar cap because they have a combination deal with their DISA valve rebuild kit.
• Copper crush washer (I can't remember exactly what it's for, I believe it's for the engine block coolant drain plug
• Water pump pulley (BMW) (optional, 11511436590): The pulley is made of plastic, so it might be worth replacing. I didn't replace mine and I think it might be wise to replace it in the near future just to be safe. Optional hex bolts and washers for said pulley (BMW, 4x, 07119904524)

Belts and Pulleys
Belts

• Accessory belt (Continental) - 11281706545 / 11287636379
• AC belt (Continental) - 11287512762

Pulleys

• AC pulley (INA) - 11287512758
• Idler pulley (INA) - 11287841228
• Tensioner pulley (INA) - 11281748131

Fluids
Oil change

• Motor oil (7 quarts) - Two good options, BMW 5W30 or Mobil 1 0W-40.
• Filter kit (MANN) - Includes filter, large o-ring, and crush washer
• Smaller o-rings (BMW, 2x) - 11427549573
• Optional: purchase a magnetic drain plug from somewhere.

Other fluids (someone will have to remind me of the capacities for these, I only have records of my sister's 330Xi which has different capacities)

• Transmission fluid - Redline MTL or Redline D4 ATF
• Rear differential fluid - Redline 75W90
• Rear differential crush washers (BMW) - 07119963355 (this one I'm not sure about. Check realoem.com and see if it's necessary).
• Power steering fluid - Redline D4 ATF
• Brake fluid - Again, several options. BMW (part no. 81220142156, 3 bottles), Pentosin DOT4 LV, or ATE Type 200 are all good options.

Miscellaneous parts

• Spark plugs (NGK, 6) - 12120037607 / BKR6EQUP
• Fuel Filter (MANN) - 13327512019
• Fuel filter soft lines - https://www.bavauto.com/b1300000
• Cabin air filter (MANN) - 64319257504
• Air intake filter (MANN) - 13721744869
• Wiper blades (BMW) - Evo version - 61610037009

Other materials

• If you're looking for some spreadsheet ideas or templates, there are a couple of them over on this thread here (I quite like mine since it has service intervals built in and some other useful tabs ): http://www.zhpmafia.com/forums/showt...-Show-Us-Yours!
• If you're considering new wheels, I had a short thread on them over here: http://www.zhpmafia.com/forums/showt...Size-Questions

[danewilson77]

Welcome

Sent from my S8+

[johnrando]

Welcome.

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[Chest Rockwell]

Sweet baby Jesus I didn't expect that detailed/quick of a response. Thanks that really helps.
So looks like I'll do this for now:

1) Cooling system
2) Underdrive pulleys/belts - do I really need to do a new water pump too?
3) Brakes are needed so I'll do those before suspension. I'll upgrade to SS lines and get new disks/pads. Do I need to rebuild or buy new calipers?
4) DISA - I'll try and do the kit myself to save $$$
5) Flush/replace ALL fluids
6) CDV delete
7) M3 engine / tranny mounts
8) Reinforce subframe if money allows
9) upgrade all steering/suspension bushings which are probably shot - which ones do you suggest I do? I believe our cars already have front/rear sway bars correct
10) I NEED BLUETOOTH CELL HOOKUP BADLY!. I do a lot of work calls while I'm driving and would like to have it integrated with the factory radio. I have the HK premium stereo. Do I need the GROM audio bluetooth box or is my case more simple? My car says pre-wired for cellular. I've attached the factory option sheet for reference and also a screen shot of the GROM I'm looking at.

Later:
1) Suspension
2) LSD
3) Shark injector, intake, exhaust mods
4) Reinforce subframe if not already done
5) strut tower brace

Thanks all-

CAR.pdf

[san]

2) do I really need to do a new water pump too?
Yup

3) Do I need to rebuild or buy new calipers?
Nope

9) upgrade all steering/suspension bushings which are probably shot - which ones do you suggest I do? I believe our cars already have front/rear sway bars correct
Yup.
Start with fcabs, rtabs, sway bar end links front and rear. Diff bushings and subframe bushings if needed. Check for steering play and maybe replace the steering coupler. Also check the driveshaft guibo and replace if necessary. It's difficult it to say which bushings needs to be replaced as their conditions vary a lot based on a lot of things but it's worth it to check all of them and replace accordingly...


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[BMWCurves]

I agree with San. Also, I wouldn't say M3 transmission or engine mounts are an immediate maintenance item, you can certainly hold off for a bit

[slater]

1) Reinforce rear subframe. It’s been inspected and has no cracks as of now. What’s the latest on the best way – I’ve seen the bar method and the plate method. Doing a quick look at the E46fanatics DIY this looks like something I don’t want to do and should take it to a shop...

[*]Subframe cracking isn't as big of an issue in late model year E46s. Other members like Peter (username Slater) will tell you that it is inevitable that the subframe will crack and he may be right. It's a matter of risk assessment but I don't plan on doing any reinforcement anytime soon. Peter's much more knowledgeable on the subject, so have a discussion with him.

first off... and i AM going to be picky about this, because, well, correct terminology is important.

it's the floor, or more correctly, 'RACP' (Rear Axle Carrier Panel), that is what cracks and eventually separates from the chassis of the car. the subframe is a replaceable, mostly-tubular metal structure that the diff and suspension bits mount to, which in turn mounts to the RACP.

with that out of the way:

- post-10/2004 E46s had a factory 'reinforcement' piece/panel sandwiched in between the upper and lower panels of the RACP. presumably it is there to strengthen the RACP and prevent twisting, but i've never seen a cutaway of it so i can't be certain. if you remove one of the plugs in the upper section of the rear floor (in the trunk), you can feel it in there. personally, i have not heard of a post-10/2004, non-M E46 having any cracking or RACP failures - and the 3 post-10/2004 E46s that i have owned or currently own (02/2005 ZHP coupe, 05/2005 ZHP coupe, and 10/2004 325iT) were 100% crack free. but that does not mean it is possible.

- all facelifted E46s had additional spot welds in the RACP to help prevent tear-out. i'm pretty sure this actually happened around 2001/2002, but for sure all facelifted cars (that means ours) have them. this has proven to not be enough.

- many factors contribute to RACP failure. worn subframe and diff mounts, and aggressive driving (hard launches, hard throttle on/off, high lateral loads). these are enthusiast cars, so the latter can and should be expected - let's not beat around the bush here.

- my own personal ZHP (06/2004 build date) has a crack in the RACP 'kink' near the left rear subframe mounting point, where they all crack first. the RACP also started separating in the left rear wheel well (definitely more common on M3s, but can happen on non-Ms). i consider myself a very smooth driver (i'm not a clutch dumper), but i did drive the car pretty hard - high lateral loads were not uncommon, especially after installing an LSD.

"so what the heck, man? why are you all doomsday and stuff about this? what do i DO?"

in my opinion, the correct solution is to redirect the load path to the rear frame rails. for some reason - packaging, perhaps - the E46 rear subframe mounting points do not tie into the frame rails (this was subsequently addressed on the E9x platform), and combined with thin sheet metal - well, it just isn't a robust solution. i personally will be installing a 'VinceBar' reinforcement kit in my 325iT (soon to be 330iT ZHP) as that solution, in my opinion, is the correct one for both eliminating the possibility of RACP failure, and prolonging the life of the E46 chassis. the VinceBar does indeed redirect the load path for the rearward mounts to the rear frame rails, and reinforces the frontward mounts. it does all of this without welding, and also without losing any trunk space or usability of the car - it is completely hidden. win/win/win/win/win.

i don't work for vince or anything. i just think his solution is genius. and good things should be praised.

Sweet baby Jesus I didn't expect that detailed/quick of a response. Thanks that really helps.

you will find that this community is a bit different than other online forums. there is a lot of brotherly love. and not much pride.

10) I NEED BLUETOOTH CELL HOOKUP BADLY!. I do a lot of work calls while I'm driving and would like to have it integrated with the factory radio. I have the HK premium stereo. Do I need the GROM audio bluetooth box or is my case more simple? My car says pre-wired for cellular. I've attached the factory option sheet for reference and also a screen shot of the GROM I'm looking at.

that GROM unit - the BT-3, i think? - is the exact one i am eyeballing. it looks like it does everything needed, all with the factory head unit, which i really like. unless your car has bluetooth from the factory (should be on the build sheet - have you run your VIN yet to get that? check www.bmwvin.com), this should be exactly what you want/need - it supposedly works perfectly with the stock steering wheel controls. but, like of all these things, i think the head unit needs to be in AUX mode for it to work.

oh, and - WELCOME!