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N62 Z3 Part 29: New Garage & New Roads

Fast forward a few months from where the last post left off and at this point the car is mostly just ... finished. I do still plan on some cosmetic stuff down the road - painting, new interior, etc. And it still needs some little things like different wheels (fronts are still rubbing) and some power steering work but it's drivable as-is and frankly, a blast. But I recently bought a home, so most my time has gone into that the past few weeks. A side benefit of that is that my car collection has been downsized and consolidated and all my cars are finally with me, at my house, where they belong. That also means my main focus for the foreseeable future will be finishing up all the projects I've had on the backburner while working on this swap The house sort of just worked out, we got pre-approved and this was the third house we looked, well under our max approved budget. Closing took about two weeks from making the offer to having the keys. Neighbors on both sides are car guys, neighbor across the street is a car guy. My first week he started up one of the dragster hot rods in his garage and just let it idle and I felt like I was where I belonged lol. He needs some brake lines run so I'll bust out my fancy brake line flaring tool and help him out when he's ready


In the new garage...



Side yard/backyard area... plenty of room for activities. The concrete slab is on borrowed time though, within a couple years we plan on putting a pool there... at that point, I'll probably get a slab poured where the cars are sitting now and a gate to block off that area



The E39 wagon needs some work to be daily drivable again for my fiance, so that's the main priority. My black coupe (S54 swap) needs the trunkfloor reinforcement, so it's ass is on the concrete so I can jack it up and get it on jackstands for the surgery. The Ranger (a Mazda B2300 to be really pedantic) needs a fuel pump, but I love that little truck - it's actually the vehicle I've owned the longest. Tahoe doesn't need anything, it's just back there to keep the others company.


And I took the car for a little drive today. Been helping someone else with a ~top secret~ swap he has planned and all that swap talk got me motivated to go drive my own, despite the 100F+ temps. Though I think it was actually a little cooler than what my phone told me and I even hit some rain on the way back...




Beautiful curvy road just a few minutes from me, lots of turns, lots of elevation change, pretty quiet as far as traffic too - I'll be learning this road very well I have a feeling!



Just had to sneak this last picture in because I love seeing the air filter peek through


So that's about where the car is at. I'll still be driving it and I do need to finish the exhaust for it, that's probably the last *major* task on this car. But again, getting the rest of my fleet back into shape is the main priority for now



Hey optimistic past self from a few weeks ago (these blogs are a running work-in-progress post that gets updated until I feel it's too long), don't get ahead of yourself!


It has been smoking, small amounts, but continuously, for awhile now. I though it was residual that would have to burn off from the CCV saga and valve stem seals from cylinder 8 from awhile ago. But it was just too persistent for me to continue to believe that was the case. I think I was lieing to myself to avoid what I really knew it was... for those who have been staying tuned, I had to dig back in to re-do the valve stem seals on cylinder 8. At the time I had a hunch I should have also done 7. And as it ends up - well, yes, I should have



Yikes. (cylinder 5, 6, 7, 8 in order)


Honestly I was a little experimental with those cylinders as they were the last I did and I mentioned it somewhere when I did the job initially that I thought the pressure of the spring pushing on the seal would have, you know... seated the seal to the head. It ends up this is not the case. It really still doesn't make sense to me why it didn't, but that's a live and learn thing I guess


All I did was remove the seal, clean the mating surface and then push the seal all the way down against the head for both intake valve stem seals on cyl 7. The exhaust area was clearly visible and were seated properly already



So here we are, again. Yeehaw. The job wasn't that bad as access is really remarkably good... it's not any harder than doing a VCG on any stock Z3 engine, you just stand on the opposite side of the car to do it. But I did have to take the brake reservoir out to take the valve cover out



All back together. I hit up a local junkyard and plucked the brake reservoir from an E46. Much thinner. Should be able to remove the valve cover without removing the brake reservoir in the future


In the garage with it's S54 coupe brother



I also built myself a little work bench. Nothing crazy here, but this job highlighted the need for some temporary work space until the third bay in the garage is cleared and can be made workable.



I took it for a long drive and it didn't smoke at all during cold starts. It smoked a tad at operating temp. Then longer into the drive the smoking diminished... which is what you'd expect if it's burning off residual oil. By the time I got home there was no smoking at all (knock on wood) so hoping this is the end of that once and for all.




*Narrator voice* but that was not the end of it once and for all


I've been daily driving this car so have been on a mission recently to eradicate all signs of smoking and am starting to suspect there *may* be deeper troubles with my engine.


I isolated the CCV system by installing a catch can and the smoking was dropped to almost zero.


Then I vented the catch can to atmosphere and there was no smoking out the exhaust



But when I opened the hood after a drive I can see smoking out of the catch can outlet hose (the catch can I bought isn't good at it's one job)



My continued diagnostics of the CCV - suspecting that was part of my issue - revealed what I thought was excessive crankcase pressure which interferes with the intended operation of the CCV system. This can be caused by excessive oil blow by or bad exhaust valve stem seals. So yesterday I did a compression test - cyl 2 seemed a little low - did a rudimentary leakdown test, just using a hose from the compression tester to my shop air regulated to ~80psi. Tested cyl 2 a hair past TDC (in case the pressure pushed the piston down, I wanted it to rotate in the correct direction, so went to TDC then just a hair more until it was just slightly on the downstroke). Heard it rushing out of the crankcase when I removed the CCV hose. Rotated the engine until it was at TDC again, just in case a valve was open in the previous position - same condition


I did not have an actual leakdown tester hooked up, so I will be doing that next just to verify leakdown %. But, based on the volume of air, and condition it occurred - I am starting to suspect an issue with piston rings and/or scored bores (feel like I've gone down this path before when diagnosing this... definitely not the first time I've mentioned this in this build)


This is a *somewhat* known fault on the N62, one I suspect is to some extent underdiagnosed. Many people report CCV related issues, I have done tons of research on the topic recently for N62's specifically but most cases end up unresolved. Excessive crankcase pressure can prevent the CCV from working properly while also producing excess oil vapor so it would seem to me that many of these cases are from people with



I'm not too bothered by it - after all, the price I paid for the engine and transmission was a great deal, much less than you'd pay for just a transmission and flywheel... and the plan was originally to mock it up as a 4.4 and 4.8 swap down the road. So I think I'll plumb it back up with the catch can to minimize the smoking and drive the 4.4 into the ground while rebuilding a 4.8, and I may go a little deeper next rebuild - verifying the condition of the bores and maybe even just proactively installing new rings. I have an N62 timing kit so why not


I'm also thinking of taking a page out of the S62's playbook by installing S62 CCV's. An S62 CCV is pictured below



There's no diaphragm, just a constant *slight* vaccuum through the CCV. Low velocity air from the crankcase enters the port on the side, swirls around the cyclonic chamber, the oil droplets accumulate and drop down the bottom and drain into the oil pan, the remnant (cleaned from oil) blow-by gasses go up out the top port. There is one CCV for each bank


This is a very efficient system, but only really usable in engines with manifolds with low vaccuum. The N62, thanks to Valvetronic, can be run at low vaccuum. But under normal operation the N62 does use some TB action when idling, to increase vacuum at idle, specifically for the CCV operation. I would need to be able to run the manifold at low vaccuum at all times for the CCV's to operate correctly, so whether or not I can use the S62 CCV's depends on if this feature can be disabled in the tune


For the oil drains, since I'd be rebuilding the engine on a stand, I think I'd just drill a return port into the timing cover somewhere, and use a one-way valve in the return hose


The S62 system has the added benefit of maintaining the crankcase at a lower pressure - this has performance benefits, as the less crankcase pressure you have, the lower the resistance from the "air spring" in the crankcase the piston is pushing against on the power stroke. This is why dry sump engines often make more power merely from converting to dry sump







Intake experiment looks like it will work well, but the first one I bought was the wrong size. I realized this pretty much right after I bought it, but it included two MAF's and for experimentation purposes, I thought it'd be interesting to get them in and compare. This unit is from a Porsche Cayenne 4.5 V8. It uses two 60mm diameter MAF's whereas the N62 uses a 83mm diameter unit. So the Cayenne has much smaller MAF's, but within ~5% of the same total diameter. And considering the MAF itself is pretty large inside the MAF housing, I think the BMW unit provides more airflow. Just thought that was kind of interesting



Below is the Porsche Cayenne 4.5 intake section. My goal here is to keep the radiator core panel intact on the next swap, while still runing a dual intake

I also find it interesting how small the intake paths are for the Porsche intakes - the 750i dual intake I'm using has MUCH larger intake tract. The 4.5 Porsche and the 4.4 BMW engine both make pretty much the same horsepower in stock configuration, it makes me wonder if the 750i intake may be more useful on the 4.8L displacement engine, perhaps on the 4.4, I may actually be losing some power due to lower intake velocity. I think I will log my MAF values with the current setup and install the smaller Porsche stuff and see how it changes


Anyways - also got the radiator in, and swapped in a new power steering pump too






Test drove this recently too. Underwhelming tbh, for supposedly having 500hp. Not sure if it wasn't running properly, or if it's just a power to weight thing (500hp is a lot ... but in a 4600+lb sedan, maybe not enough to have that sensation of speed)

Got the car back on the road with the new radiator and temps were much cooler. I experienced my first notable failure of the car. I had observed the power steering high pressure line had a little flat spot rubbed into it from the sway bar. It hadn't been an issue before (it's been like that since pretty much my first drive with the power steering), but when I replaced the power steering pump with the recent cooling system work, the line must have settled into a different position.

I drove the car on about a 3 hour excursion and picked a friend up. He wanted to see what it could do so I flogged it on some closed private roads, and one of the times I hit a large bump at around 100mph. Steering immediately felt a little heavier and once I slowed back down I realized I had zero power steering.


I pulled over and topped it up with some p/s fluid I had in the car. Few seconds later I see a huge plume of smoke come out from under the hood... yikes. Immediate thought was the valve cover gasket from last time I did the valve stem seals must not have been seated properly. Power steering pump was whining, and a few seconds later it lost power steering again. Went to an autozone, got some p/s fluid, topped it up in the parking lot. Pump whined, had power steering for a few seconds. Then it went away... I figured either the pump failed, or the rack was completely shot at this point.


Took the highway home, slightly worried the car would burn down to a crazy valve cover gasket leak, but oddly, there was no more smoke after the initial plume. Got it home and checked it out today.

It ends up my high pressure power steering line has failed. There are signs of fluid on the headers too - so I think that plume was the ATF having shot out of the line to the headers. I think the large bump hit the sway bar into the line and a crack developed. I can wipe the line down, and immediately a few drips of ATF comes back out... ATF was everywhere


Decided to take this time to upgrade other components while I was in there and went with sone E30 M3 control arms. They look amazing and are very light. I'll weigh them vs the stock arms once I get the lollipop bushings off so it's a fair comparison. Plug and play upgrade for non-M Z3's if anyone is wondering...

E30 arms also have different balljoints, solid metal without a rubber isolator whereas E36 arms have a rubber isolator for the balljoints


I also decided to order solid M3 lollipop bushings to pair with them. I didn't want to deviate too much from my "OE" style build, but wanted to tighten up the front just a smidge. Waiting on those and new M swaybar end links and bushings to arrive



Stock Z3 control arms




10 lbs 5 oz compared to 4 lbs 2.5 oz for the aluminum arms, pretty significant difference!


Wanted to move forward with getting the replacement steering rack in but unfortunately, the steering rack I ordered arrived cracked. Didn't even notice until I came out to a small puddle where it was sitting in my garage. Should have probably looked at it closer since the box it shipped in was soaked in fluid...



But that got me thinking, maybe there are other steering racks I could install. I was looking at E90 racks and realized the E92 M3 - which has a V8 - places the steering rack input splines a bit further upwards and outwards. I need to measure one, before even consiering plopping the money down for one - but it looks interesting


The E92 M3 roughly overlaid on top of an E46 rack (what I have installed now)



Even if that rack doesn't workt his has also given me another idea as perhaps the design behind it could be applied to modifying a Z3/E46 rack to work... not likely to find it's way onto the current swap, but for future swaps I'd like to come up with a solution for using a stock style steering shaft without the center joint





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