Author Topic: E36 Radiator into E30 318is (Read 25275 times)

Ernest · « **on:** March 23, 2009, 03:24:43 AM »

I just finished the install. An e36 6 cylinder radiator WILL fit in a 318is but with more modification than I had originally thought. I still, however, believe this is a worthwhile modification. I have a completely irrational hatred for the stock m42 radiator/expansion tank design. This hatred led me to this radiator swap. Here is what I have found...

1. The driver's side lower radiator bracket is too long and will not allow the e36 radiator to drop in. The solution is getting the corresponding bracket from a LATER e30 325 from the junkyard. *You can also remove the plastic airflow block off that is in front of the stock M42 expansion tank assembly, since there will now be radiator area for air to actually flow through.

Here's the original bracket:

M42 bracket/Later E30 M20 bracket Side by side:

New bracket installed:

2. The stock M42 upper radiator hose will NOT fit. Even if you were to install an extension pipe by cutting the radiator hose in half, the stock hose will still interfere with the stock airbox.

The solution I came up with was using a NAPA hose #7315 and trimming it to fit. It seemed to fit the bill perfectly.

3. If you are using the stock clutch fan, you will need to get creative and find a way to both seal the driver's side of the shroud to the radiator AND secure it to the radiator. I stuck a length of silicone window seal from home depot to an aluminium L-bracket and riveted it to the side of the shroud.

4. Lastly, you need an expansion tank from a later E30 325 and modify the block-expansion tank hose to reach the new expansion tank location. I was able to do it with a 5/8" 90 degree hose fitting. (This is not visible in the picture.)

The new set-up appears to be working as it should. The real test will be when I go back to LA and sit in traffic. I'll let you know if anything changes. I would like to go to an electric fan, but if the stock fan continues to do its job, I doubt I'll switch.

JP 91iS · « **Reply #1 on:** March 23, 2009, 11:35:09 AM »

So why do you hate the stock radiator/expansion tank setup? I always thought it was nicer...

finite · « **Reply #2 on:** March 23, 2009, 11:43:54 AM »

cus they blow up

Ernest · « **Reply #3 on:** March 23, 2009, 02:00:41 PM »

Quote from: JP 91iS;68801

So why do you hate the stock radiator/expansion tank setup? I always thought it was nicer...

I always thought it was needlessly complicated. A non-circular seal that is press-fitted in place that will see both high pressure and heat?

I developed a leak at the expansion tank/radiator seal. I bought a new expansion tank and installed it. I could have bought just the seal, but I wanted a new expansion tank because the original one had become very dark and discolored and it was difficult to see the coolant level. The coolant leak got even worse! As I pull the radiator/expansion tank again, the radiator cracks! The only reason I could come up with was that the replacement radiator was a Valeo and the new expansion tank was a Behr and somehow the two different manufacturers manufactured with slightly different clearances.

At this point I'm sick of dealing with this design and I have to get a new radiator anyway. I didn't want to go with an m42 radiator again. The information out there about e36 radiator swaps make the swap seem easy enough, so it seemed like a reasonable upgrade? From both the mishimoto e36 radiator group buy thread and PMing a member who had done the swap, I had been told the swap in a complete drop in. The only modification being you need to acquire an m20 expansion tank. Well, that's just untrue. There's no way the e36 radiator will drop in without changing the bottom bracket, AND there is no way the stock radiator hose will fit. If someone still wants to say otherwise, I'd love to see the pictures of their install.

tonywonder · « **Reply #4 on:** March 31, 2010, 08:17:41 PM »

lol shit man i just did this today and i ordered oem radiator hoses thinking it would all be fine and dandy. and ill be damned the damn top hose aint long enough. ill be ordering that NAPA hose. i just removed the bottom rad brackets for now but ill have to get the mounts you did to properly fit it.

DesktopDave · « **Reply #5 on:** April 01, 2010, 06:11:37 AM »

I wonder if a later 325 radiator would fit?

tonywonder · « **Reply #6 on:** April 01, 2010, 11:31:35 AM »

i actualloy put a mishimoto radiator into mine. im still working on it right now cuz i have to fit my elctric fan i bought as well.

Ernest · « **Reply #7 on:** April 02, 2010, 12:19:41 AM »

Quote from: tonywonder;90300

lol shit man i just did this today and i ordered oem radiator hoses thinking it would all be fine and dandy. and ill be damned the damn top hose aint long enough. ill be ordering that NAPA hose. i just removed the bottom rad brackets for now but ill have to get the mounts you did to properly fit it.

I'm glad my writeup is helping at least one person out! Let me know how it goes dude.

tonywonder · « **Reply #8 on:** April 06, 2010, 01:12:35 AM »

yeah this definitely helped especially when i put the radiator in and went..."oh shit now what?"

i removed the plastic ariflow block off and put one mount back on. the driver side mount is just off now. as for the expansion tank hose i managed to make it work without the 90 degree fitting you suggested. but ill have to see if that will still work when i change the hose for a new one. the old one was pretty flexible. i also used a different upper radiator hose. its still NAPA but its a different number. ill write in what i did differently later. ill have to take pics and write the numbers down. the mishimoto radiator is good. im running it with no fan and it stays under half so far. i havent run it during the day yet and it was particularly chilly tonight

tonywonder · « **Reply #9 on:** April 06, 2010, 07:46:21 PM »

This is the setup i have. expansion tank fit and connected to block expansion tank hose without 90deg coupler. but i had to work it through the power steering hoses and under the intake box then up to the expansion tank.

The Upper Radiator Hose is a NAPA #9683, cut at the end that goes to the thermostat housing. the elbow at the radiator connection just touches the air box. it fits well.

i have two smaller hoses running off the expansion tank at the cap. one that goes to the radiator at the top and one that goes to the radiator using the fan mount as a support to run off to the ground.

i am not running a coolant level sensor.

i have an 88deg wahler thermostat and will be installing the e36 rad temp switch for the auxfan that i just received today.

the switch actually hits the plastic headlight housing protector thing (passengerside), the radiator is a bit large for the switch to fit perfect. ill have to figure something out for that maybe cut a hole in the side of the shield. or just leave it as is.

Appletree IS supercharged · « **Reply #10 on:** April 09, 2010, 02:51:41 PM »

Hi do you have the real oem part number or the age and engine size the radiator you fitted came from?

dont realy understand how the expantion tanks work but where have you put the hose that usualy goes to the bottom left of the rad undder the "top hose" thats slightly smaller in diameter.

I'd idealy like to fit the expantion tank were the battery would go, would this be possible as ive a superchargeer in let pipe were yours is :-)

E30tii · « **Reply #11 on:** May 29, 2010, 08:46:21 PM »

Getting ready to do this once I source a radiator, as my third M42 radiator is now leaking…I'm done with the plastic integrated expansion tanks!

I picked up the M20 mount and expansion tank, however I have a question: how are you guys mounting the expansion tank? On the M20 car I pulled it from, there is a bracket welded to the wheel well and another "nub" that a plastic mount screws onto, however, my car has neither of these, as there was never anything intended to be in that spot.

Also, probably a stupid question, but where does the smaller of the two hoses running off the cap of the expansion tank go? I can tell that one goes to the radiator, but there is a smaller one that was disconnected on all the cars I saw at the junk yard, and I'm not sure where this one will be going.

PumpItUp · « **Reply #12 on:** May 30, 2010, 02:16:27 AM »

god. i am fed up with this

on rev i seen some 6cyl owners were converting to m42 radiator for its integrated expansion tank. here we're converting back

it would be funny if it wasn't so brain numbingly depressing

dude8383 · « **Reply #13 on:** July 06, 2010, 04:52:35 PM »

Quote from: E30tii;93026

Also, probably a stupid question, but where does the smaller of the two hoses running off the cap of the expansion tank go? I can tell that one goes to the radiator, but there is a smaller one that was disconnected on all the cars I saw at the junk yard, and I'm not sure where this one will be going.

I believe that the one that isn't connected is supposed to be routed to the ground...this is the bleeder.

rufiox426 · « **Reply #14 on:** November 05, 2010, 06:56:33 PM »

what happens to the lower radiator hose on the m42 radiator when doing this swap?

#4 in picture