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There are lots of oil cooler threads out there, but almost no one has really documented a factory setup - especially the ducting around the hardware.
After running a track day last week with 106*+ ambient temps (and 140* surface temps), it's apparent I'll HAVE to run an oil cooler if I want to avoid having to take some cool-down time every two laps or so. (COTA is around 3 minutes / lap, so a full cool-down lap is a bit much).
The Euro / Z3M setup seems to be the cleanest by far - especially with the factory thermostat for a street driven car that still has AC and is driven year-round (in Texas, but still - I don't need cold oil making my life harder). And adding the bigger Zionsville cooler seems to be pretty straight forward, but there are some undertray fitment questions there.
I currently have a Mishimoto rad, which has been trouble free, but I've also heard they can be prone to blocked passages, and they lack the mounting tabs for the cooler. Given the benefits Brett expounds of the Z3M rad I think this is a case of letting myself be talked into a better setup, even if it needs to be replaced periodically vs an all-aluminum rad. (The CSF aluminum rad also has mounting tabs is my backup choice).
So back to the question - there are some cascading complications around ducting that I've not found good answers to.
1) The US fan shroud (remember, this is a street car that just sees a couple - very hot - track days a year). Some say the US shroud blocks the oil cooler - is this correct? Is it just the bottom lip? Can that be trimmed, or do you just need to get the Z3 shroud (https://www.fcpeuro.com/products/bmw...-17112227684)?
2) Undertray. I've read the Z3M rad is shorter to accommodate the oil cooler for a combined total stack-up height that's the same as the stock M3 rad. Which appears correct from what I can tell. I've read conflicting info that advises getting the Euro front-end ducting to feed the oil cooler. Maybe both of these are true? Maybe the US ducting is shorter to seal at the US rad without the oil cooler? This looks likely from some of the other ducting discussions we've had here.
I can see that this ducting splits the air ahead of the rad / cooler, but I don't see that splitting the airflow ahead of the rads is necessary. I re-read sirhodjibob's ducting thread and I think I've answered this question - I think we decided that with the GT front splitter you delete that ducting.
However, the Zionsville oil cooler is taller - has anyone used it and can comment on fitment? Improvement vs the factory cooler? I'd be happy to stick to factory if the Zionsville cooler makes fitment a giant PITA and doesn't provide a marked increase in cooling...
3) Mounting hardware. I can't find a good view that shows how the factory cooler mounts to the factory Z3M rad. I see the tabs on the cooler - and I see the slot on the bottom / sides of the rad, but just the driver side. I don't see how you slot the passenger side or bolt it in or whatever. Again, despite searching, I've found very few pics of a stock cooler mounted to the radiator with the tabs and with the factory ducting in place. I know a Euro E36 M3 and an S54 Z3 will be very similar - but yeah, I've found very few pictures. Sirhodjibob's ducting thread is about the best I've found for pictures, and will be super helpful sorting out all the ducting, but was not focused on to the cooler mounting. (https://www.bimmerforums.com/forum/s...-Air-Duct-Help).
If anyone goes back and re-reads that thread, I had plans that never panned out. The GT splitter never arrived, so I then punted on the high-rise wing too (which is just sitting in my attic). And that all looks tidy in retrospect - I can just do it more or less together and just do it once, with the front and rear aero and the oil cooler and everything and just do it one time.
So, feedback on these three areas? Other relevant observations?
-Josh: 1998 S54 E36 M3/4/6 with most of the easy stuff and most of the hard stuff. At least twice. 271k miles. 1994 E32 740il with nothing but some MPars. 93k miles.
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"After running a track day last week with 106*+ ambient temps (and 140* surface temps), it's apparent I'll HAVE to run an oil cooler if I want to avoid having to take some cool-down time every two laps or so. (COTA is around 3 minutes / lap, so a full cool-down lap is a bit much)."
I'm interested in knowing what your coolant and/or oil temps were to get you to this decision.
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you will also need the euro oil filter housing that has the ports for the oil cooler. only issue is that it rubs against the stock alternator air feed so you will need to trim that.
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I pushed water temps to 230* repeatedly before taking a cool-down stretch. I'd let it drop down to 208 or so before getting on it again, which would buy me about another 1.5 - 2 laps.Originally Posted by aeronaut
This was a bit uncharacteristically hot, but 100 isn't out of the ordinary. I doubt I'll be on track with those kinds of temps frequently, but that's how it is down here from about June through September.
Yeah, I'm aware of that (fairly minor) issue, and yes, that's my preferred approach vs one of the cap solutions.
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I am running the Z3M radiator, Euro oil cooler and S54 oil filter housing.
Stock underpanels fit fine. But I ditched them and got the turner underpanel instead. The OEM radiator shroud needed a bit of trimming on the driver side (literally 1 minute of work with a cut off wheel) so it could clear the oil cooler pipes. The rest of my ducting is stock US and it works fine. I have no temperature issues even on 100F+ track days at Thunderhill.
The oil cooler bolts up the radiator with one 10mm screw, the opposite side slides into the tab and it is very secure. I uploaded some pics, hopefully it helps. Another note, I had to trim the stock alternator duct so the oil cooler pipes could clear.
This is also a good time to ditch the stock clutch fan and upgrade to a SPAL fan.
What are your oil temps getting up to? If it is anything under 260F I wouldn't bother with the oil cooler for a street car.
IMG_9433
IMG_8158
Last edited by Johal E32; 06-23-2022 at 01:58 PM.
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Agree, if your oil temps are under 260 or so, I'd focus on primary solutions for coolant temps.
Even in 100deg heat, you shouldn't be seeing 230 coolant temps.
The Mish radiator and Z3M radiator are essentially the same in cooling efficiency.
Go Mish-X, or other larger capacity radiator (can't remember if any of those allow keeping the mechanical fan).
Other than radiator capacity, the options to lower running temps are:
Triple check ducting, and seal any gaps.
Remove rear shroud.
Remove A/C condenser.
Add hood vents.
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Good point.
I should mention that my car has the AC removed. This includes the compressor, receiver drier, all engine bay lines, AUX fan, and the AC condenser.
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Oh wow, then yea, I'm a bit surprised at your coolant temperatures.
I saw 10-15 deg reduction with hood vents.
I have no fans, z3m radiator, decent but not perfect ducting, hood vents. I may see 200-205 on our short, high-rpm track in 95 deg heat. On our bigger track (summit point main), never above 195.
Do you have a mostly stock S52? Higher HP output changes everything.
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i do think keeping the ac and using it in these hot conditions under hard use is at the limits of the cooling system capabilities. ive seen a few weird temp spikes turning the car off stopping at gas stations/stores driving through all the insane elevation changes local to me. turning the car back on to see the coolant gauge at 3/4+. this dosnt seem to be a common experience, but i have a m3/4/5 like blckstrm,
i dont think trimming the stock shroud is a good idea unless you modify it to seal it back up. its kinda bowed out from the radiator in the area an oil cooler would sit. its probably easer to just replicate the z3m radiator setup in its entirety on the engine bay side. at least we all know the z3m setup works in the z3m. proper hardware sounds very difficult to sort without having all the parts in your hand. ive been researching the 4cyl z3 powersteering setup and started to notice that the z3 is certainly a different car.
aeronaut's track build thread shows a power steering cooler behind the foglight area in the bumper. i bet an oil cooler with similar specs to the oem cooler could be put in this location. and fed through the fog light and exited through the fenderliner. just a thought.
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I'll try to snap a pic next time I am under the car. The radiator shroud is sealed up. The total amount I removed from the shroud is minimal and only to clear the oil cooler pipes.
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hmm i was thinking you clearanced the entire area of the oil cooler.
that does bring in to question how the exit side of the z3m is setup. seems kinda self defeating to separate inlet air to remerge it on exit with a upwards turn. my google image search isnt locating anything useful.
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IMG_8158
Let's say the white line is the perimeter of the original fan shroud. I removed literally an inch just around the oil cooler pipes.
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That I think is fairly easy to navigate. But I thought this "issue" referred to the engine-side fan shroud blocking the oil cooler. Granted, I've found little in the way of pictures or even good explanation. By the time most people get to this point they're usually ditching lots of factory stuff, with the AC and fan shrouds first on the list (i.e. long gone) by the time they're working on installing an oil cooler.
So my desire to keep everything makes it a little more unknown.
...
I have both the AUX fan and all the AC system, as well as the rear fan shroud with an electric puller mounted inside of it. (if it helps, pics and description of that here: https://www.bimmerforums.com/forum/s...1#post29196261 )
Engine is mostly stock, just some of the normal bolt-ons (ASC delete, M50/tune, Raceland long tubes - which are wrapped) - nothing that would add a lot of heat. I never see temps above 215 on the street, even on the hottest days (115*) at speed.
My thermostat is failed open, and it does occur to me that it's possible it's stuck somewhere between closed and fully open. I haven't noticed higher than normal temps on the street, but the track is certainly a different situation.
I'll replace the thermostat when I do the rest of this, but I'm doubtful it's the source of the problem. That's wrong - not problem, but the weak link here. I just don't think the system was designed to handle that much heat AND abuse at the same time.
Also, @aeronaut, I've been thinking about hood vents for a long time - intake temps in traffic in the summer are brutal, and I think this would help with both issues. I'm close to pulling the trigger on that, too, but again, this is a street car and I'm not completely at ease with the idea of hood vents in the rain. I like the look of the GTR-style vents, but I don't think they're the most effective - I think a center vent is the most effective given this is where the PTG factory race car had them (maybe with some side vents also). (And yeah, I know the E46 GTR came after the E36 race car, so maybe they figured out that the GTR locations are optimal. More homework, right?).
In any case, cutting up my hood isn't reversible and a whole new fiberglass hood is a lot of money to spend if I decide I hate it.
Last edited by blckstrm; 06-23-2022 at 02:33 PM. Reason: Fixed link
-Josh: 1998 S54 E36 M3/4/6 with most of the easy stuff and most of the hard stuff. At least twice. 271k miles. 1994 E32 740il with nothing but some MPars. 93k miles.
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If you compare the shroud slots on both sides with the 3rd pic from my fan install ( I think it looks like the bottom of the shroud will pass across the middle of the cooler - and yeah, it will also need to be trimmed to clear the inlet/outlet hoses.
Let's say the white line is the perimeter of the original fan shroud. I removed literally an inch just around the oil cooler pipes.
Having said that... I'm not sure that's a bad thing. It just means it'll get lumped in with the radiator as far as the fan goes.
And this is all assuming the total stackup-up height isn't different - I've read that the Z3M rad was shorter to accommodate the cooler within the same packaging area. Johal, what's your total height from the bottom of the cooler to the top of the rad? Mishimoto lists the overall height of mine as 18.3".
-Josh: 1998 S54 E36 M3/4/6 with most of the easy stuff and most of the hard stuff. At least twice. 271k miles. 1994 E32 740il with nothing but some MPars. 93k miles.
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thats a useful pic. after doing a radiator a few weeks ago i thought the oe fan shroud would extend further down into the oil cooler area and that that cooler was basically in the foot print of the normal e36 radiator. im apparently mistaken.
I still have all factory parts and the hood insulation intact. seems im in the same boat as you blckstrm. i just dont have headers. id personally not want to cut holes in my hood. but alot of other cars like to pick the rear of the hood up to get effective cooling. maybe a similar airflow can be accomplished by pulling the rubber seals off the windsheld cowl or hacking up the cowl a bit.
there isnt many of us driving stockish sedans hard. there isnt many sedans in the first place.
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Haha, yeah, that's true.
I'm not sure you're mistaken - I'd like to see how tall both are together. I've read the Z3M rad is shorter...
OK, Schmiedmann has dimensions (https://www.schmiedmann.com/en/17112...renginecooling) - core width (height) is 410mm, or 16.1" - which is about an inch shorter than a normal E36 core which is 17.25" (including the Mishimoto. So I think the OE E36 shroud DOES extend down into cooler area - it looks pretty close based on the pictures from my fan thread and these from Johal.
...
As for venting, you can pull the weather stripping from the rear under the back of the hood and/or space the hood up a little, but the air flow is down - the base of the windshield is a high pressure area and it forces cooler air into the engine bay rather than extracting it. So it doesn't help with coolant temps, though it could be beneficial for under hood temps. In fact, the E9x M3's hood "vents" are actually intake for the V8 (well, one of them is - the other one is purely cosmetic for symmetry).
An oil cooler for me is significantly more attractive than vents. Someday I may pull the trigger on a MASHAW vented hood to keep my original one from getting trashed, but until then I'd rather keep my hood stock.
-Josh: 1998 S54 E36 M3/4/6 with most of the easy stuff and most of the hard stuff. At least twice. 271k miles. 1994 E32 740il with nothing but some MPars. 93k miles.
Member
I will get you some measurements and better photos of my fan shroud setup later this evening.
Previously, I had this setup with the entire AC system before and I had no issues. This includes the AC AUX fan and AC condenser.
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Are you using the E36 fan shroud or the Z3 one?
-Josh: 1998 S54 E36 M3/4/6 with most of the easy stuff and most of the hard stuff. At least twice. 271k miles. 1994 E32 740il with nothing but some MPars. 93k miles.
Member
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Looks you're already on the right track for ducting...I can't help much with the oil cooler as I haven't gotten around to installing one yet. I do have the Z3M radiator which has 2 slots at the bottom for presumably the oil cooler.
Here is my original radiator compared to the Z3M Behr (left), you can see it is slight shorter:
I did replace the fan shroud with 17111723031. I believe the Euro M3s used 17112227684.
The oil cooler ducting that splits the air is 51-71-2-253-303. I do believe this is compatible with the non GT undertrays....I never figured out where 17212227344 goes, but perhaps it attaches to the oil cooler itself.
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I think we finally determined that it is shown backwards (or upside down - or both!) in RealOEM. The flat part goes between the rad and the oil cooler. You have to insert it and then tighten the bolt, which sandwiches it tight. Then it curves down to direct the air flow from the oil cooler down under the car.
[Edit] I've ben thinking through the system, and I think this part is there to provide support and stop the undertray from bowing away from the oil cooler at speed because of air pressure. Those three legs point downward and bolt to the back side of your aluminum undertray [/Edit]
Also, thank you for the pic of the two radiators side by side - this is exactly what I wanted to see. I think with the oil cooler the combined setup will be a little taller than the E36 rad alone, but I think that's pretty solveable.
Quick question - how is 17111723031 different than stock? It looks identical - are the dimensions different?
Last edited by blckstrm; 06-24-2022 at 02:12 PM. Reason: Inspiration
-Josh: 1998 S54 E36 M3/4/6 with most of the easy stuff and most of the hard stuff. At least twice. 271k miles. 1994 E32 740il with nothing but some MPars. 93k miles.
Member
About halfway down this thread is this picture: https://www.bimmerforums.com/forum/s...g-Legal!/page4
So, I think if I go with something like a CSF 3054 (the one in the picture is a C&R, but is also full E36 size) which is both E36 size but also includes Euro cooler brackets I'll clear the shroud issue. I think a giant Zionsville oil cooler would be nice, but probably overkill and might also create problems with extending below (or pushing against) the undertray.
In other words, I think the CSF + stock oil cooler will package, and also nail down the shroud issue. I think a Z3M rad + stock cooler would package and leave most of the cooler inside the shroud, and Z3M Rad + Zionsville oil cooler would package, but leave the shroud issue to be sorted. And I think the CSF rad + Zionsville cooler will be too tall to fit unless I idid something like install a splitter that sits lower than the bumper (which is where my current undertray is). That's not really something I want to do.
-Josh: 1998 S54 E36 M3/4/6 with most of the easy stuff and most of the hard stuff. At least twice. 271k miles. 1994 E32 740il with nothing but some MPars. 93k miles.
Member
I am wondering if anyone has considered repurposing the transmission oil cooler off an automatic for use of cooling engine oil.
BMW Transmission Cooler - ACM 17201728770 | FCP Euro
It has a lower profile and sandwiches between the support and radiator.; so it also gets cooling benefit of the aux fan operating.
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My stock shroud paired with the Z3M radiator does not block the oil cooler in any way. I know my photos suck, if I have time I will remove the Turner underpanel and show you that the stock shroud is not an issue with the Z3m rad and euro oil cooler.
17111723031 for the shroud.
17212244084 for the oil cooler.
17112227281 for the radiator.
If you look around you can find the oil cooler pretty cheap, I paid less than $170 for mine directly from BMW within the last 2 years.
Member
yeah thats why this seems desirable glad to know that this setup dosnt have unexpected problems. thanks for the info.
never thought about the automatic trans cooler, that does seem like a an awesome power steering cooler though. i do recall something about using the e30 oil cooler. it might have been that it didnt work....but i think it was usable in an e30 with a m5x swap possibly.
im still wondering what the underside of a z3m/ m3gt/ 318clubsport looks as delivered new. there is another underside plastic cover as well that covers some part of the trans tunnel area or the area behind the subframe. im unsure of its application if it was for more pedestrian or harsh environment cars or m3's i haven't seen this posted in along time and my realoem search hasn't been helpful.
Last edited by scoobiedoo2029; 06-24-2022 at 06:53 PM.
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