Cooling system questions

[Roysneon]

What I have going on right now is a late 325 E30 rad with an IE pusher fan. The temp goes up above the half way mark, just around the 3/4 mark.

My questions are as follow.

I want to go back to a 318 rad (My car is a 318i) for a cleaner looking bay with the built in expansion tank. I'm using an E36 lower hose and a stock, uncut M42 upper. Do I need different hoses for the other rad? Is there a silicone hose set that will work with an M50tu and an M42 rad? Are there any aftermarket rads with a built in tank?

Any suggestions on how to make it run cooler? I know going to an M42 rad can't help much and will theoretically hurt it. I still have the stock thermostat and water pump, those are on the list, I'm running straight water until I'm confident that I have the cooling setup finalized. Besides what I just mentioned, what should I add to the list?

[frankie591]

lower temp fan switch will help, but if a 325 rad is running at 3/4 temp, a 318 rad will run hotter than that.

[golde30]

Which tstat you running?

[7pilot]

I'm running S52 with an M42 radiator with BMW coolant and 2 bottles of water wetter, lower T stat and Lower fan switch. The gauge reads with the pointer just touching the left side of the half way hash.
All new sensors and components.
In stop/go traffic, the pointer is one width past halfway, at which point the electric fan is activated.

A friend of mine has used this radiator with an S50 swap on the track in the midwest for a few years and no issues.

If you use quality new components you should be ok. If you use old used components, you'll get bitten.

m

[Roysneon]

Which tstat you running?

Whatever was in the motor, likely the factory original. I had to rush my swap as my old motor crapped out on me suddenly.

[golde30]

Run the e30 80deg tstat and drill a 1/8 hole at the 12oclock position. Bleed the system again, you shouldn't see the temp go past 1/2.

[atldohc]

Run the e30 80deg tstat and drill a 1/8 hole at the 12oclock position. Bleed the system again, you shouldn't see the temp go past 1/2.

+1. i run the lower temp switch and thermostat and the highest the temp gets is a hair past halfway. i actually regret buying the mishimoto radiator bc the quality was subpar and the stock radiator worked just fine.

[cormier]

Curious, how did you find the mishi subpar?

Ive heard nothing but good things

[Roysneon]

I have my Ireland Eng. fan running constantly (waiting on thermoswitch to come in) and it's still getting way too hot. I guess I'm gonna do the thermostat and bleed the system again over the weekend.

[JRKOUPE]

Ive been having some issues too w/ running at 3/4 mark.

u realize that many e36 folks will say at 3/4 you already overheated..and prolly need a new thermo..lol...and will need a new hg......

Im already paranoid about it.

[Roysneon]

OK so here's whats going on

1. I'm tired of working on this car
2. The temp rises normally, then once it gets to half way it takes about a minute and the gauge shoots up.
3. The heat in the car is ok until about the half way mark, then after that, when the car is supposedly extremely overheated and eating the cylinder head, there is no heat.

Would the thermostat do that? Water pump? Both/either?

[TimKninja]

You need a lower degree thermostat, and it doesnt sound like its bled right.

[Roysneon]

Yeah, we forced coolant into the rad and upper hose and its a LOT better. Next time I put together an order from Blunt or IE I'm gonna add the 80 degree thermostat. The E36 stock one is 88 if my research is correct.

[7pilot]

OK so here's whats going on

1. I'm tired of working on this car
2. The temp rises normally, then once it gets to half way it takes about a minute and the gauge shoots up.
3. The heat in the car is ok until about the half way mark, then after that, when the car is supposedly extremely overheated and eating the cylinder head, there is no heat.

Would the thermostat do that? Water pump? Both/either?

Keep at it. it is still not bled.
Your attempts should be restricted to 15min max per session. Time the sessions and you'll be automatically protecting the head gasket.

m

[Boostesi]

you deffinetley have air trapped in the system, drill hole in the thermostat, also check to make sure your gauge on your dashboard isnt a filthy liar, mine is, it will say im overhearting i give my dash a little slap and it goes right back in the middle lol