overheating at idle, I am pretty sure it's bled. (m52 obd2 content)

[Daeldalus]

I was trying to bleed my system today. m52 with m20 clutch fan and m20 radiator and late model overflow tank.

jacked up the front 2 feet, filled system it took 2 1/4 gallons, turned heater on full blast, started car and kept topping up whenever it was low. squeezed top hose a bunch of times until bubbles stopped coming out of the overflow hole.

now at temp lots and lots of hot air coming out of the vents. rev'ed it up a few times to make sure to flow the coolant into all the spots didn't take much more coolant maybe 2.5 gallons in total.

i had a obd2 reader hooked up the whole time to make sure of the actual temp reading. it went past 195 and straight on up to 217 before i just turned it off.

now here is the weird thing. top rad hose was burning hot and the bottom hose and the entire radiator were both stone cold, like just at room temp cold.

still air in the system? if so how to fix that? squeeze the bottom hose too?

or maybe thermostat(it is brand new)?

[m3boost]

wait until its cool... remove resv cap, undo top radiator hose from rad....grab ahold of the hose and start adding coolant in that hose so coolant goes to the head.. keep adding until you see coolant dripping out of the opening of the radiator. quickly place the hose back on to the radiator and tighten the hose clap..top off the the required coolant on the resv...I've done it this way plenty of times and most if not all air is pushed out..start the car let it get to operating temp. after about 10 minutes of idling. shut it off and let it cool completely, better yet, let it cool off over night. The next day before starting it again, remove the cap again and sometimes but not all the time, more coolant will be sucked in by the engine.. add more coolant as required.. if it still overheats, the issue is not air in the system

[Mwishlist]

+1 on filling via the top radiator hose. I had the same issue with overheating at idle with the same set up, when I first got my swap going. Got the same advice and as soon as I filled via the top hose it worked like a charm.

[Daeldalus]

tested thermostat and radiator, both fine.

then bled system as described here. now I am getting heat into the bottom hose and across the radiator, but it still got up to 212 before i decided to shut it down. It took a much longer time to get up to that temp and i was able to drive it around some.

my condensor fan is not wired up yet and my clutch fan feels a little weak. could that be now what it going on?

how hot can i safely let it get to to test if it will start coming back down? 220?230?
the car has a 198 thermostat in it, so 212 isn't that much higher but...... I am not using the cluster temp gauge but i am going to wire in a aftermarket one that reads numbers like i am doing with the obd2 reader, so maybe i am just a bit paranoid about the numbers....

[NC325iC]

idk what the numbers are on mine, but with the e30 dash temp gauge mine will run just a hair over half way on the highway. I just think the s52 runs a little hotter than the m20.

[Northern]

If the rad/lower hose is still cold, either your t.stat isn't opening, you're air locked, or something else is preventing flow.

[Daeldalus]

Lower hose now gets warm, probably 120f to 140f as well as the radiator which is really hot on the drivers side and goes down to warm on the passenger side.

I have ordered a 80c thermostat and fan switch to see how much that helps. I really probably should not have used the 198f thermostat.

[IRON-E]

Hmm, always though that 24v is the easiest thing to bleed out, compared to m20.

[Daeldalus]

I never had any problems with my m20 car.

Jack up the front and open the bleeder screw a few times, never runs hotter than 1/2 the gauge

[m3boost]

tested thermostat and radiator, both fine.

then bled system as described here. now I am getting heat into the bottom hose and across the radiator, but it still got up to 212 before i decided to shut it down. It took a much longer time to get up to that temp and i was able to drive it around some.

my condensor fan is not wired up yet and my clutch fan feels a little weak. could that be now what it going on?

how hot can i safely let it get to to test if it will start coming back down? 220?230?
the car has a 198 thermostat in it, so 212 isn't that much higher but...... I am not using the cluster temp gauge but i am going to wire in a aftermarket one that reads numbers like i am doing with the obd2 reader, so maybe i am just a bit paranoid about the numbers....

Get a Meyle fan Clutch... and wire your electric fan and you should be fine...