My M30-Swapped Alpine Coupe

[iso_hi]

So my dumbass installed the thermostat backwards. I'm still going to install the new 71c and drill a small hole at the top.

[e30RS]

Color combo is fantastic and really loved that daytime photo with the popout wimdows open. Good luck with the thermostat.

[iso_hi]

new thermostat is probably a good idea. glad to hear things are working out bit by bit

Yeah at this point I'm certain it's the thermostat. It takes way too long to open. The temp gauge was close to the 3/4 line and the lower hose side was cold and the other side burned me when I touched it. It opened shortly after but it was like minute 15 by that time.

The car had a 71c tstat when I pulled the head and I replaced it for a 80c. I have another 71c on the way. Let's hope this helps because I'm pretty certain I've been bleeding it right the entire time. Hopefully this helps someone looking to do a M30 swap without a heater. Even though I might be the only one.

[wworm]

new thermostat is probably a good idea. glad to hear things are working out bit by bit

[iso_hi]

I just opened up the the extra 19mm bolt on the thermostat housing and then the bleed screw while the engine was barely warm. A hiss of air came out and the coolant almost came out of the 19mm bolt. It's level almost to the top so I'm hoping that was the last bit of air. I'll try the car out in the morning, too loud to let it idle for 20 minutes in my backyard right now.

Regardless, I ordered a 71c thermostat/gasket and proper coolant hoses to remove the current hose extender and plug. I also hit up e30_dad for a cluster quote.

[iso_hi]

I've always hated bleeding BMW engines, from the M42 to the M20 and now the M30.

I got the Frank M M30 guide thanks to wworm's suggestion. It confirmed my previous post about the cooling hoses. They should have been plugged rather than looped when doing a heater delete. I fixed that and bled it again, this time raising the expansion tank as I filled. It seemed to bleed just fine but when I drive it stays at about the 3rd line with the fan on and looks like it rises a bit when I drive it hard. When stopped at a light it lowers a bit. I'm starting to think something is up with the thermostat. It is a new 80c unit. Should I use a 71c unit since I have no heater core? I also couldn't find a gasket for the thermostat, just the o-ring. It leaked originally so I used gasket maker for the first time smh.

After bleeding the cooling I start the engine and let it idle with all the caps and bleed screw closed. The lower hose stays cold until the temp gauge almost reaches the 3/4 mark and then it drops to almost 1/2 and then thats when the lower hose gets hot. After letting it sit a bit more it starts getting closer to the 3/4 line again but doesn't overheat. This is all with the fan off. Is this as good as it gets without a heater core? I'm considering getting my cluster refurbished, new thermostat housing, 71c thermostat, new coolant hoses, and maybe an aftermarket gauge as well but I'm trying to save cash since I have Coachella coming up next month ;D

[iso_hi]

I have only a little bit of input to add. glnr12 is right, it shouldn't be bouncing around. Mine used to do that, till i changed my timing belt, bled the system and then it never bounced. I then replaced a hose that led off the throttle body to the block and ever since the gauge has been bouncing. my only idea is that there are pockets of air that are causing the gauge to bounce like it is due to the air being hotter than the coolant. So i've been bleeding the system for like two weeks now having the front up on ramps to see if i can get it all to make it's way out of the system.

I guess to summarize, i think the bouncing is due to pockets of air in the cooling system.

I don't know I think I've bled it pretty well. When I open the thermostat screw it's just a steady stream coming out. The expansion tank stays at the normal level after it cools down. Even the thermostat opens while I drive it because the lower radiator hose gets warm.

I ordered new ground cables but I'm going to try unlooping the lines because I think that will solve my issues.

[jeenyus]

I have only a little bit of input to add. glnr12 is right, it shouldn't be bouncing around. Mine used to do that, till i changed my timing belt, bled the system and then it never bounced. I then replaced a hose that led off the throttle body to the block and ever since the gauge has been bouncing. my only idea is that there are pockets of air that are causing the gauge to bounce like it is due to the air being hotter than the coolant. So i've been bleeding the system for like two weeks now having the front up on ramps to see if i can get it all to make it's way out of the system.

I guess to summarize, i think the bouncing is due to pockets of air in the cooling system.

[glnr13]

I don't know if your reroute will make much difference but I will say that the temp should not be bouncing around like that. I drilled 1/16" hole in my thermostat to help bleed the system and car stays below 1/2 mark unless I'm in stop and go traffic. Leave me at a light for too long and that temp goes up quick.

I have a spal 16" that brings the temp down fast. Be sure you have the fan gasket, helps a ton.

[2mAn]

I know this look isn't for most E30 or BMW fans. I love an E30 on HR Sports with Euroweaves as much as the next guy but for this car I'm just doing what I feel.

I love it.

[iso_hi]

I'm going to go with a 3.46. I was playing around with the final drive ratios on Forza 7, while it's not a perfectly accurate representation since I used an S38-equipped car, it definitely gave me a better idea of what I want.


Ok, and now I want to vent about some cooling issues. Pun intended.

Since the day this car was bought I have never been confident in it's cooling system. The previous owner said just run the fan whenever I'm driving. The gauge would always fluctuate from the middle line to the red zone. It would never reach the red but it would never stay in the middle either. I've always just thought this is how M30 swaps were because of lack of clutch fan.

I've changed every cooling bit. From radiator, to hoses, to new thermostat bleed screw. The radiator and pump came after a hose burst on my first long drive (About 40 miles). It still runs the same even after all this recent work.

But I think I may have figured it out. I would like some feedback before I drain the coolant again.

I went over the swap on many threads and on the e30 wiki. Everything is the same as what I have aside from the lack of a heater. It was supposed to be a drift build before I came in so there's no heat/ac. The fan doesn't even work or I'd try and put heat back.

From the E30wiki it shows two sets of hoses that go to the heater core, as they should. PO skipped that and added an extra piece of hose that tied everything together. There was a huge piece of hose that went from the radiator back to the starter, where it had a kink blocking flow, and then to the expansion tank. I thought that was my issue so I simplified it to my revision. That hasn't worked which made me read more today and maybe have finally realized my mistake.

From E30 Wiki - M30 Swap


PO's Heater Delete


My "Revision"



I'm thinking this is way better than his version because A) it get's rid of the kink near the starter and B) less hose? I obviously don't understand too much about coolant flow and other technicalities.

Fix?


After reading more today and discovering new info I realized me and the PO are both wrong, instead of looping they should have been plugged. So I think my fix is to separate those two line from that T connection and that'll essentially be the same as if I would have plugged them from the beginning.

I don't know what I'm doing. Any input?

And some good news. I found a cheap storage unit where I can keep a car and parts. 3rd car coming soon?

[LJ851]

I personally like the 3.46. 3.25 good for a lot of highway driving

Solid M30 advice.

[glnr13]

I personally like the 3.46. 3.25 good for a lot of highway driving

[wworm]

ive always wondered why people do the yellow strip between the lip and the valence. I like the little yellow hits on this car and the wheels look great. TBH it looks sick as low as it is but would prob ride nicer a lil higher lol. Where in the bay are you? I've been thinking about an m30 (among a million other power plant options) and would love to go for a ride in this thing if youre close.

[iso_hi]

I just drove the car for like an hour and it's great. I'm loving the NT05s.

The one thing I now have to change, which I knew I should have done in the past month or so, is... the diff. The 4.10 it has right now is ok around the city or short sprints but anything above 65-70mph for over 3 seconds just sucks.

So question to the M30 swap guys, what diffs have you tried and are they tolerable on the highway?