M30 Radiator yak chips

[Hector]

Yesterday I replaced the radiator of my 4-cyl Mazda. Just for the hell of it, I decided to compare the new ALL metal Mazda radiator with that from my m30 which has been out of the car for a while. To my surprise, both radiators were almost the same size, give or take about 0.5". Unorthodox german engineering? Who knows. Anyway, there have been times when car has overheated (temp gauge needle at almost 3/4 mark) a bit when stuck in bumper-to-bumper traffic in hot weather. Specifically, in Baker, CA enroute to Vegas on I-15 where temps can easily reach 120 C+ in Aug. BTW, this doesn't happen to the Mazda.

I guess, the larger 6-cyl demands more quenching of thirst. I read awhile back on some web site that the some 325i owners had modified there cooling system by installing a larger radiator and expansion tank to overcome this problem, I think. Anyhow, this is something I might contemplate in doing later when I get the time.

Trivia for thought.
Hector

[ryan roopnarine]

additive and.....are you sure that your auxiliary fan switch is werking correctly?? its supposed to come on at, IIRC around 190 degrees or so....i'd check your fan clutch when it goes back on too.....these cars apparently operate at high normal operating pressures, 20+ psi.

[George M]

Hey Hector, you pull the rocker shafts from your M30 head yet?
George

[Tiger]

That is one way... the other way is like Bavarian suggest... changing the thermoswitch to lower temp so the electric fan kick in earlier to keep car cooler. They are saying once it goes over the normal range, it is hard for the radiator to dissipate the heat so they say by kicking the fan on earlier, it prevents that...

Personally? I would go larger radiator if you can... but you need to make sure you use the radiator shroud from the same larger radiator car and retrofit it into your car... you gotta have suction across the whole radiator or you have hot spots.

[Hector]

but I'm not a big fan of water wetter anymore. I had this stuff in the radiator before and when the water pump crapped out, I noticed a syrupy red gunk around the pump shaft where it was leaking. I read that the redline wetter is supposed to lubricate the pump. I hope I'm not contradicting myself but this happened several years ago when I wasn't BMW wrench savvy so it could have been something else that caused the pump to fail. I've learned a lot in the last 2 years from trial and error, literature, and more recently from tips in this board. If you and others haven't had any problems with the wetter, then maybe I should give it the benefit of the doubt!

The aux fan is/was working right and the clutch fan has been replaced but can't remember if has been done since then or after. I yak about this because it's not an isolated incident--it's happened several times and sporadically.
Hector


additive and.....are you sure that your auxiliary fan switch is werking correctly?? its supposed to come on at, IIRC around 190 degrees or so....i'd check your fan clutch when it goes back on too.....these cars apparently operate at high normal operating pressures, 20+ psi.

[Hector]

The good part is that it was easy to slide all four shafts out, and this could indicate the head is not warped. Cheerio!!

The kinda bad part was that I inadvertently added fuel to the fire between you and Bill R. If I had tried to pull the shafts out before asking how to do it in this forum, I would've lessen some of the fuss you guys had going. It's just that after reading the Bently manual that you can mushroom the shaft ends by hammering 'em out by brute force, I got myself in a "too cautious" mode and was expecting the worse. Live and learn.

I didn't need "helpers," screwdrivers, slide hammer or the BMW special tool to relieve the pressure off the valves to slide the shafts out. I also didn't have to pull out the camshaft first. I just rotated the camshaft so that each rocker arm pressure was relieved for that section of shaft and pulled them out piecemeal with 4 camshaft rotations. I couldn't believe how easy this was. Seems like there is always more than one way to skin a cat if you can find that one way.

Hector


Hey Hector, you pull the rocker shafts from your M30 head yet?
George

[Hector]

and I remember down side about changing the thermoswitch. Something about increasing thermal shock to the engine block. Hell, I can't remember exactly. Anyone know of this?
Hector


That is one way... the other way is like Bavarian suggest... changing the thermoswitch to lower temp so the electric fan kick in earlier to keep car cooler. They are saying once it goes over the normal range, it is hard for the radiator to dissipate the heat so they say by kicking the fan on earlier, it prevents that...

Personally? I would go larger radiator if you can... but you need to make sure you use the radiator shroud from the same larger radiator car and retrofit it into your car... you gotta have suction across the whole radiator or you have hot spots.

[George M]

well agree the whole affair is unfortunate. As it turns out, Bill and I rarely disagree. That particular day, however we did disagree on a couple of issues, one apparently Bill took personally which is regrettable. As to your rocker shafts, I wanted to save you the trouble of trumping up a slide hammer that Bill recommended as it was likely, it wouldn't be necessary...which turned out to be the case. And FYI, always best to remove the rocker shafts and arms prior to pulling the cam on an M-30. Glad you got it apart with a minimum of fuss.
George

[winfred]

i have a 540 radiator in my 535ia, ill post some pics when i get home if you want


Personally? I would go larger radiator if you can... but you need to make sure you use the radiator shroud from the same larger radiator car and retrofit it into your car... you gotta have suction across the whole radiator or you have hot spots.

[Hector]

Thanks for the offer.
Hector

i have a 540 radiator in my 535ia, ill post some pics when i get home if you want

[winfred]

i had to dick with the mounts a little, i think i cut down two right sides (smaller) and used them, and i used a tranny cooler from a e36 (like later 525s bolted to the front of the radiator) the 540 has a liquid to liquid heat exchanger below the bellhousing, and i wired the shroud on the left, the core is about a inch wider and a 1/2 inch thicker. the closest i've come to overheating with it came from sitting in the bank drive through for 30-45 minutes (inside was closed, was dropping the take from the till at work and it had to be in) it was over 100* hard to say how much it really was the obc was pegged at over 130* from radeant heat, and the ac was cranked, i was working to keep it in check with the throttle to keep it at 3/4 or less, it took about 20 minutes to get there
http://members.cox.net/wdixon27/535%20r%20motor
http://members.cox.net/wdixon27/535%20l%20motor
http://members.cox.net/wdixon27/540%20radiator

[ryan roopnarine]

how much larger is the 540 radiator than the 525i....i know i can't swap them or anything....

[winfred]

not sure about the total capacity difference, the 535 is bigger then the 525 and the 540 is bigger then the 535, but the 525 has the puke tank as part of it and the other cars have it on the firewall, it would take a bit of work but it would be possible to install one on a 525, how much better? don't know, hell i don't know how much better the 540 is then the 535, it is designed to cool another 80 odd horsepower worth of motor so it's gotta be worth something, i just happened to have a new one in stock when my stock rad collapsed internally on the way to work, so i figured what the hell it was only about $20 more my cost

[Hector]

Yeah, I can see that there would be some fiddling around with installing that larger radiator but if it does cool the 535i ever so slightly then I'll buy into it. To me that's a modification worth the effort. It's kinda annoying, even here in town when it's scorching outside, traffic is backed up, you got the AC on minding your own business, and then all sudden the needle starts to creep up to the 3/4 mark. Then you gotta roll down the window and turn the heater on to cool the engine a bit. What's wrong woth this picture? Give me a freakin' break.

I think I'm seriously going to look into this more. Since you have done, it gives me hope that this can be done in my car.

How do you like that power flow intake kit? Does that heat shield really work?
Hector

[winfred]

that's something i whipped up, the last owner just had the filter hanging from the afm, it was just sucking hot air from the manifold, i dug up a intercooler pipe with the right bend and fabed up a shield, i need to tweak the shield closer to the hood and insulate the tube. it bellows nicely when you ass down on the throttle and it's passing 3500 rpm. i think it made less power then stock sucking the hot air

[Hector]

BAS for such a jig. Thanks


that's something i whipped up, the last owner just had the filter hanging from the afm, it was just sucking hot air from the manifold, i dug up a intercooler pipe with the right bend and fabed up a shield, i need to tweak the shield closer to the hood and insulate the tube. it bellows nicely when you ass down on the throttle and it's passing 3500 rpm. i think it made less power then stock sucking the hot air