Must-fix issues Z4M e85

[Shigg614]

Alrighty so I've been doing extensive research on some of the common issues Z4M's have and have narrowed down to 3 issues that I need to focus on. The car is relatively new to me with absolutely no service records. She's a 2007 and currently has ~70k with mostly street driving. I'm starting to track the car and am looking for a peace of mind moving forward.

Issues:
1) Rod bearing replacement
2) VANOS rebuild
3) Valve adjustment (Unless this is done with the VANOS rebuild?)

Is there anything else I should be focusing on? Which issue should I be focusing on first?

[bwright657]

The VANOS and rod bearings are the only things to look at that are specific to the S54 engine. Given the age/mileage of the car and that you're tracking it. I would check all fluids, the brakes, suspension bushings, and the mounts for the engine, transmission and diff.

VANOS typically needs addressing by 75k miles. Rod bearings can usually be stretched until 100k.

Look up the S54 VANOS rattle sound on YouTube. It typically starts around 2.5-3k rpms and will get worse from there as it wears. I bought my car at 66k miles and it started rattling around 69k. I had mine rebuilt using the Beisan parts shortly after that. If you do a VANOS rebuild, you should do a valve adjustment at the same time.

For rod bearings, getting a Blackstone oil analysis can give you an idea of how healthy they are. My analysis has come back fine so I'm going to wait until 100k or the oil pan gasket starts leaking, whichever comes first.

[CTMP4me]

Originally Posted by Shigg614

Is there anything else I should be focusing on? Which issue should I be focusing on first?

1. Clutch delay valve (CDV) removal

If you're gonna track it more than once:

2. Stiffer engine and transmission mounts to prevent missed shifts/moneyshifts (Vibratechnic engine mounts + Rogue rubber transmission mounts worked for my track car)

3. Rear trailing arm bushings - either go with the limiters or replace with polyurethane versions

Look over the rest of the suspension and check condition of the front control arms, their bushings, wheel bearings, etc, and do an alignment. Change the transmission oil and diff gear oil, since that's probably never been done on the car.

[XMetal]

Originally Posted by bwright657

The VANOS and rod bearings are the only things to look at that are specific to the S54 engine. Given the age/mileage of the car and that you're tracking it. I would check all fluids, the brakes, suspension bushings, and the mounts for the engine, transmission and diff.

VANOS typically needs addressing by 75k miles. Rod bearings can usually be stretched until 100k.

Look up the S54 VANOS rattle sound on YouTube. It typically starts around 2.5-3k rpms and will get worse from there as it wears. I bought my car at 66k miles and it started rattling around 69k. I had mine rebuilt using the Beisan parts shortly after that. If you do a VANOS rebuild, you should do a valve adjustment at the same time.

For rod bearings, getting a Blackstone oil analysis can give you an idea of how healthy they are. My analysis has come back fine so I'm going to wait until 100k or the oil pan gasket starts leaking, whichever comes first.

What makes you so sure you can go 100k on your rod bearings? Blackstone oil analysis only works if you have a strings of reports to look at from day 1. Otherwise it's pretty much useless if you only got the last few. What would you be looking for in the report? Spike in lead? Once the lead layer has worn away, you're not going to see much lead in your Blackstone report. So, then spike in copper? You may or may not see that either. If you browse through my Oil Analysis thread, you can see my bearings are already into copper at ~55k miles, but there's no signs of copper being out of the ordinary!

[Shigg614]

Originally Posted by CTMP4me

3. Rear trailing arm bushings - either go with the limiters or replace with polyurethane versions

Are you pointing to these? https://vorshlag-store.com/products/...nt=32750002695

Originally Posted by bwright657

VANOS typically needs addressing by 75k miles. Rod bearings can usually be stretched until 100k.

Hmm I might wait until then (or until the rattle that you mentioned becomes noticeable) as my indie quoted me about 3k for VANOS rebuild and 3k for swapping out the rod bearings...

Are these prices reasonable?

[86Zed]

100% agree that you should have a reputable independent BMW specialist do a thorough inspection of the car (PPI, basically) and see what wear items may need replacement or updating if you are not comfortable doing so yourself.

I would suggest a pad upgrade - stock rotors and DOT4 fluid work well but you risk pad deposits with OEM or similar street pads. The rest of the items you can tackle as you start to familiarize yourself with the car and experience it on track.

For what it's worth, VANOS and rod bearing overhauls are items to consider as you approach high mileage but the forums vastly understate or overstate the criticality and timing of it. Some have tackled them before 50K miles while others approach 90K miles and plenty of track time without addressing it yet.

[bwright657]

Originally Posted by XMetal

What makes you so sure you can go 100k on your rod bearings? Blackstone oil analysis only works if you have a strings of reports to look at from day 1. Otherwise it's pretty much useless if you only got the last few. What would you be looking for in the report? Spike in lead? Once the lead layer has worn away, you're not going to see much lead in your Blackstone report. So, then spike in copper? You may or may not see that either. If you browse through my Oil Analysis thread, you can see my bearings are already into copper at ~55k miles, but there's no signs of copper being out of the ordinary!

Very fair points. From my own research across the Z4/E46 forums and advice from my local BMW shop, the general consensus seemed to be that the VANOS is on borrowed time after 75k and the rod bearings after 100k. Of course your mileage will vary based on use, maintenance and luck.

Originally Posted by Shigg614

my indie quoted me about 3k for VANOS rebuild and 3k for swapping out the rod bearings...
Are these prices reasonable?

We would need some more information here about the parts they're quoting you and the shop labor rate. I wouldn't recommend putting OEM BMW parts in for either system. Follow the Beisan guide for the VANOS. BE Bearings or WPC treated bearings are popular replacements, but that's also a huge debate point. Going back through my records, I spent around $1500 in parts for my VANOS rebuild and my shop charged 9 hours of labor for the VANOS rebuild, anti-rattle, timing chain guide, valve adjustment and oil change.

[XMetal]

Originally Posted by Shigg614

Hmm I might wait until then (or until the rattle that you mentioned becomes noticeable) as my indie quoted me about 3k for VANOS rebuild and 3k for swapping out the rod bearings...

Are these prices reasonable?

3k for rod bearings is a bit high - is that for OE bearings? My indie charged me a shade under 2k out the door for the swap using WPC treated OE bearings.

Can't comment on the VANOS as I had a "friend" that helped me rebuild mine at a discounted rate.

[pyshin]

Does the $3k for the vanos rebuild include all Beisan System parts along with a valve adjustment?

[1stw0rldpr0blems]

I replaced my original rod bearings at ~140k miles, which is longer than my water pump lasted. They did look a little worn but my blackstone analysis always came back fine, and I did it for peace of mind. Granted I don't track or race my car, its a daily driver. S54 bearings don't wear out nearly as fast as S65/S85 bearings.

On the vanos side of things, that got overhauled right around 150k miles. I had a broken tab on the oil pump hub, and the tip of the upper timing chain tensioner was snapped off. Car ran fine otherwise. I noticed the broken tab during a valve adjustment, drove the car for about 5k more miles before I had the money to overhaul the entire system.

If you can't do all at once, I would prioritize rod bearings first, and then vanos after. You can see the tabs on the vanos hub during a valve adjustment, which could probably be the most catastrophic thing to fail.

[XMetal]

Originally Posted by 1stw0rldpr0blems

I replaced my original rod bearings at ~140k miles, which is longer than my water pump lasted. They did look a little worn but my blackstone analysis always came back fine, and I did it for peace of mind. Granted I don't track or race my car, its a daily driver. S54 bearings don't wear out nearly as fast as S65/S85 bearings.

On the vanos side of things, that got overhauled right around 150k miles. I had a broken tab on the oil pump hub, and the tip of the upper timing chain tensioner was snapped off. Car ran fine otherwise. I noticed the broken tab during a valve adjustment, drove the car for about 5k more miles before I had the money to overhaul the entire system.

If you can't do all at once, I would prioritize rod bearings first, and then vanos after. You can see the tabs on the vanos hub during a valve adjustment, which could probably be the most catastrophic thing to fail.

Agree that rod bearings should be prioritized over VANOS. While it's true that you can see the tabs on the VANOS hub during a valve adjustment, but you can't check those camshaft hub bolts without taking apart the hub cover.

The tip of the upper timing chain tensioner appeared to wear out in about 50k miles or so. Mine was on the verge of snapping off when I changed it under 50k. Beisan appeared to have an upgraded version...may consider that on my next go around.

[1stw0rldpr0blems]

Originally Posted by XMetal

Agree that rod bearings should be prioritized over VANOS. While it's true that you can see the tabs on the VANOS hub during a valve adjustment, but you can't check those camshaft hub bolts without taking apart the hub cover.

The tip of the upper timing chain tensioner appeared to wear out in about 50k miles or so. Mine was on the verge of snapping off when I changed it under 50k. Beisan appeared to have an upgraded version...may consider that on my next go around.

Yes true, cam bolts cannot be seen w/ the valve cover off. Mine were fine but I changed those anyway. I went with a rebuilt vanos unit with upgraded seals, anti-rattle components/ splines, S62 diaphragm springs, Beisan upper chain guide, cyro hub, Rogue vanos oil presure line, and even a new vanos accumulator. I basically upgraded whatever could be upgraded so hopefully I'll never had to address the vanos system again, lol.


Also, if you happen to have an oil leak coming down the passenger side of the engine block, and you can't figure out where its from. Its probably the CPV o-ring thats leaking, and should be replaced/upgraded with a viton O-ring. Something I would recommend doing if you're removing or upgrading your headers. It could run down and soak the passenger side of the transmission bell housing and fool you into thinking its a rear main seal leak.

[wdb]

Originally Posted by CTMP4me

1. Clutch delay valve (CDV) removal

If you're gonna track it more than once:

2. Stiffer engine and transmission mounts to prevent missed shifts/moneyshifts (Vibratechnic engine mounts + Rogue rubber transmission mounts worked for my track car)

3. Rear trailing arm bushings - either go with the limiters or replace with polyurethane versions

Look over the rest of the suspension and check condition of the front control arms, their bushings, wheel bearings, etc, and do an alignment. Change the transmission oil and diff gear oil, since that's probably never been done on the car.

Nice list. I'd add a 'short' shift kit in there; the Auto Solutions kit I installed makes 2nd gear *much* more approachable from above.

[CTMP4me]

Originally Posted by Shigg614

Are you pointing to these? https://vorshlag-store.com/products/...nt=32750002695

I ran this kit since 2014/2015: turner RTAB shim kit.

As far as rod bearings go, Blackstone is a good "canary in the mine" at best. My rod bearings at 112K km and about 30K km of that at the track were almost toast, so I am willing to swap them out as a maintenance item every 4-5 years if the car sees significant track time or lots of starts below 30F temps.