Z4 parts: OEM-feel for non-OEM prices?

E85 Z4, 2003 3.0. I've decided to tackle the issues: roof motor, maybe even the torn roof, insecurely-attached front bumper cover, brakes all around, "thrust mount bushings" (That's what the dealership called it.), front struts and springs, rear shocks and springs, bushings(??), maybe headlight assemblies since they're so worn looking, emblems.

What all do I need to get to bring it back to life and get it into shape? What kinds of bushings, reinforcement plates? My top strut mounts are cracked too.

I'd like to get it back to OEM feel, at the very least. Before, when I thought I'd take it out more, I asked before about upgrades to the suspension but taking it a track is getting less and less likely now and I'm afraid of having any more harsh of a ride;  doesn't better performance == more harsh ride?

I'd love some advice, here's what I've been thinking so far:

SUSPENSION:

RockAuto has a variety of struts here, are the OEM-level Bilsteins just fine? By fine I mean, are they the cheapest because they're crap or is it just cheaper to make it the same ride quality as OEM?

Same for the OEM-level shock absorbers on the rear, is Monroe a decent brand? Of course there's rule of thumb of not buying the cheapest, but maybe someone's had some experience to tell me otherwise.

I don't even know where to look for reputable springs. RockAuto doesn't sell them, nor Amazon. eBay does, for what that's worth. I'd take a whole kit from someone but they tend to run over $1k and are all for improved performance.

When looking for "thrust mount bushings on YouTube and Google I didn't see anything Z4 specific. Are thrust arm bushings the same? or a control arm bushing?

BODY:

The sides of the bumper cover keep wanting to fall down. It seems like the only thing holding it in place are those little tabs in the inner fender dust cover (for lack of the technical term) - is that how it's supposed to work? My dust cover is all torn up. Surely the front end was bumped at some point. There's a crease between the two kidneys up front too.

I'm not particularly well versed in the E85, but any time you're looking for BMW parts you should really be using RealOEM.com as a resource. It will give you the specific part numbers you need and that really helps track down and compare prices.

Generally, when it comes to suspension components for BMW's I'd recommend sticking with OEM suppliers (Lemforder, Meyle, Febi/Bilstein). In the case of your dampers that's likely Sachs, but a Bilstein B4 or B6 might also be an exceptable replacement.

Thrust arm bushings are control arm bushings for the lower control arm that connects to the back of the front knuckles, at least that's the case in the E39. It's likely those are worn and in need of replacement.

Given the age of the car, if you intend to keep the car, I'd recommend replacing most of the bushings, inspecting all of the control arms for wear, and replacing where necessary. Even if a bushing looks ok, at this age, it's likely that they have deteriorated. It's likely that all of this won't be particularly cheap, but you'll have a car that feels as close to "like new" as you're going to get.

Springs rarely go bad, so unless they're rusted to hell I'd just do shocks and struts. Bilsteins OEs should be fine. As far as the rest of the suspension, the bushings are all likely done at this point. The thrust arms are what BMW calls the front upper control arms. It's easier to just buy the arms and replace the whole part rather than pressing bushings. If it were me I'd do all the control arms front and rear at once, along with the sway bar bushings and end links. If you can find polyurethane inserts for the rear subframe mounts, do those at the same time.

Brakes are straightforward. I like Zimmerman for rotors, as they're about the last ones made in Germany and I've never had an issue with them. I prefer OE pads - Jurid or Pagid are the usual suspects - for their bite even when cold. They do dust, but it's a price I'm willing to pay.

Finally, be very alert to the state of the cooling system. The M54 engine does not like overheating and will lunch itself in an astonishingly short period of time. Everything in that system is suspect at this age. Standard practice is to just to the whole system at once every 100k miles or 10 years - OE parts shouldn't be more than $600 or so.

FCP Euro is your friend for parts here.

There are a number of suppliers who can provide OEM or OEM quality parts at a discount from dealer prices.  I like Blunttech: https://www.blunttech.com

Like using realoem.com, this site can get you the factory service repair instructions. 

https://www.newtis.info/tisv2/a/en/

02Pilot said:

Springs rarely go bad, so unless they're rusted to hell I'd just do shocks and struts. Bilsteins OEs should be fine. As far as the rest of the suspension, the bushings are all likely done at this point. The thrust arms are what BMW calls the front upper control arms. It's easier to just buy the arms and replace the whole part rather than pressing bushings. If it were me I'd do all the control arms front and rear at once, along with the sway bar bushings and end links. If you can find polyurethane inserts for the rear subframe mounts, do those at the same time.

Brakes are straightforward. I like Zimmerman for rotors, as they're about the last ones made in Germany and I've never had an issue with them. I prefer OE pads - Jurid or Pagid are the usual suspects - for their bite even when cold. They do dust, but it's a price I'm willing to pay.

Finally, be very alert to the state of the cooling system. The M54 engine does not like overheating and will lunch itself in an astonishingly short period of time. Everything in that system is suspect at this age. Standard practice is to just to the whole system at once every 100k miles or 10 years - OE parts shouldn't be more than $600 or so.

FCP Euro is your friend for parts here.

What were you saying to address about the cooling system? Like everything rubber?

In reply to P3PPY :

No, like all of it. Radiator, water pump, expansion tank, thermostat, hoses...all of it. The expansion tank is probably the #1 failure point, but the rad is close behind - hell, even the stupid plastic bleed screws are known to fail (replace them with brass). It's not that you might not get away with it for a little while, but once it starts you'll just end up replacing everything anyway, and probably killing the motor the one time you don't notice until it's too late.

In reply to P3PPY :

Lots of the BMW specific vendors sell "kits" for the most common replacement parts for these cars.

FCP has a kit for the brakes

https://www.fcpeuro.com/products/bmw-brake-kit-front-and-rear-zimmermann-akebono-34116864058ktfr2

And for the cooling system from ECS:

https://www.ecstuning.com/b-assembled-by-ecs-parts/ecs-cooling-maintenance-kit-level-2/17117573751lv2a/

I'm not sure if the Z4 is as susceptible to radiator issues but you might also want to add that to the kit I posted above. That should cover it on that end.

MTechnically said:

In reply to P3PPY :

Lots of the BMW specific vendors sell "kits" for the most common replacement parts for these cars.

FCP has a kit for the brakes

https://www.fcpeuro.com/products/bmw-brake-kit-front-and-rear-zimmermann-akebono-34116864058ktfr2

And for the cooling system from ECS:

https://www.ecstuning.com/b-assembled-by-ecs-parts/ecs-cooling-maintenance-kit-level-2/17117573751lv2a/

I'm not sure if the Z4 is as susceptible to radiator issues but you might also want to add that to the kit I posted above. That should cover it on that end.

That’s beautiful! Thanks for the kit links!! Do you happen to know of one for suspension?

also, my springs in the back have indeed rusted thru at the bottom; according to one YouTuber that’s a Z4 thing

In reply to P3PPY :

Here is a kit for the front from FCP:

https://www.fcpeuro.com/products/bmw-control-arm-kit-8-piece-e46-oem-e46cakitl

And here is a link for a kit that is supposed to address some of the short comings of the rear suspension design:

https://www.ecstuning.com/b-assembled-by-ecs-parts/rear-suspension-refresh-kit-level-2/33326770824kt10/

Again, I'm not familiar with the specifics of the Z4, so this might be just what you need or somewhat overkill.

MTechnically said:

In reply to P3PPY :

Here is a kit for the front from FCP:

https://www.fcpeuro.com/products/bmw-control-arm-kit-8-piece-e46-oem-e46cakitl

And here is a link for a kit that is supposed to address some of the short comings of the rear suspension design:

https://www.ecstuning.com/b-assembled-by-ecs-parts/rear-suspension-refresh-kit-level-2/33326770824kt10/

Again, I'm not familiar with the specifics of the Z4, so this might be just what you need or somewhat overkill.

Thanks, man. I feel kinda lazy now like “here let me google that for you,” but thanks. 

Spring is almost here in Michigan. I did the suspension, headlight refresh and new roundels last year.

It's time for a tune up. At a stoplight it won't even chirp the tires, and then I test drove one that had been well used and it was like a burnout machine. FCPEuro again on this one?

I'm looking at https://www.fcpeuro.com/products/bmw-comprehensive-service-kit-e85-e85compsvckt

and the coils from this kit: https://www.fcpeuro.com/products/bmw-ignition-service-kit-12138647689kt3

Anything else I should be looking at for loss of power? Maybe my tires are just too sticky ;)

heh, I doubt that. Even my old 318ti could chirp the 235/45/17 starspecs I had on the car.. and it had the optional "winterpackage" limited slip

If you haven't addressed the cooling system, please do it unless you enjoy watching an engine die as the temperature gauge goes from fine to I'M MELTING...! in seconds.

My indy swears he can tell seconds into a test drive if a car has been driven enthusiastically or not. Do your service and then drive the car good and hard for a few weeks (like redline at least once every time you get it warmed up - I like a full throttle acceleration from zero to, um, "highway speed"). I bet you'll be able to chirp the tires after that.

While you're in there, I'd recommend installing a DISA valve repair kit. The valve gets brittle over time which leads to power loss and potentially bits of it ending up in the engine. German Auto Solutions sells a decent kit.

Gently clean the maf. Have you run a scanner on it for any pending codes? That tune up kit looks fine, possibly look for any vacuum leaks from cracked intake boot/rubber hoses connected to the oil seperator system.

May want to inspect the valve cover thoroughly while you are changing plugs since it's right there ready for you to fix if it is seeping. 

No I haven’t run a scanner. Will any cheap OBD II scan tool find codes?

In reply to P3PPY :

Nope. You need something that will read the BMW-specific codes - there are a bunch of handheld scanners that will do the job and aren't too expensive. Very handy for live data and running diagnostic tests as well.

Not sure of the shocks on the E85 3.0 and on the M are interchangeable but if they are, the BC Racing units are excellent and can be had with whatever springs you ask for.  I use them on another car and will certainly go that way if I ever decide to change the shocks on my Z4MC.

I did just go thru with Bilsteins this past fall, so I should be good there, but thank you