M30-E30 Cooling hose configurations

[e30_kid89]

First off Id like to give full credit to doughnut since i "borrowed/edited" his uber baller diagrams.

The first pic is how my cooling system is hooked up, key thing is im using BOTH the e28 upper and lower rad hoses. This is how the cooling system is set up in the e28 535i from looking at the diagram in the bentley:



Cruising it runs low to the 1/4 but in the summer and hot traffic it overheats. See anything wrong with this setup?

My proposed setup:



I notice guys who arent having over heating issues using the e34 top rad hose, and if i understood what good&tight was saying in this post:

The only thing I would question then is the coolant line configuration. On my B34 the upper radiator hose T's off to the expansion tank.

On his setup the expansion tank is hooked up from the thermostat housing which would explain why coolant is being pushed into the tank and pressurizing it. Coolant flows from the back of the head back into the thermostat housing.

I think he should try using an upper radiator hose that has a T to go to the expansion tank and just route the back of the head to the thermostat housing.

It makes sense but i just want to make sure i can actually beneift from adding the upper hose because i'm not looking foward to bleeding the system :(

Any suggestions?

[chadthestampede]

I never had issues and mine looks just like your first picture.

[xwill112x]

i thought normal operating temp was right in the middle?

[talltorontoguy]

The bleed is not bad. You can use the bleeder screw, or loosen temp sensors. Best done on ramps with nose up.

[wildstoats]

What fan are you using? I was using a supposedly high CFM Permacool unit and it couldn't keep the system cool. I switched to a Spal and have had no problems since. Good fan + good bleed = win. For the record my setup is like the first picture, aka the stock e28 configuration.

[Doughnut]

e30_kid89, Is "Good & Tight's" quote that you put in your last post specific to the b34 only?

i thought normal operating temp was right in the middle?

I believe that the m30 runs a little cooler than the original engine in my car, hence it only registering "normal operating temp." at 1/4 on the gauge.

Also, my original diagram of the m30 cooling system was for the b35: