E36 318is overheating

[OreoE36]

I have an e36 compact with a 318is engine in it. The engine was good but it had a couple leaks so i decided to take the engine out and redit all the gaskets including headgasket (it had no issues before)
After puting the engine back in the car now overheats.
Here is what happens
I turn the car on and let it iddle (the temp gauge gos to the middle in like 40 seconds. The thermostat (new) opens and then the temp gauge starts going up to the the red until it is red. The hoses from the radiator are not hard as if it had pressure in it but when i open the bleeder bubbles come out and then steam as if it did have pressure.
YES i did bleed it correctly trust me.
I like to think i know these cars but im at a dead end. If i drive the car at around 50kmh on low rpms the temp goes past middle but not red. If i drive hard it goes to red.
Heres a list of the parts that are new (mind you all the old parts were fine because i had never had a overheating issue, not even o track or drifting:

Water pump
I’ve tried 3 different radiators (including the old one)
Thermostat
The plastic hose that goes in the bloc
Clutch fan
Headgasket
Radiator cap

I also see no coolant leaks
The only different thing the car has now that it didnt before is that i removed the charcoal filter, i doubt my proble has anything to do with that.

ALSO! I did a co2 test to chec if my headgasket was the problem but the test came out negative.

PLEASE SOMEONE HELP
I dont know what else to do and i love the 318is

[Eric93se]

Still, it sounds like air was still in the system. The straight six can easily be damaged by going into the red, I do not know if the same is true for the 4-banger.

Did you use the standard thickness HG? that is crucial. Was the head planed to ensure its perfectly flat? You used brand new head bolts? and followed factory torque sequence.

Also the cooling when driving sounds like a bad water pump or thermostat that is not operating properly. Don't ever let you engine go anywhere near the red, shut it down, get it towed home if possible. People 'limp' their straight six home and just ruin the head (cracked/warped).

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Welcome to the forum!

[3two5]

X2 on the question of head resurface and was t-stat tested before installation?

[OreoE36]

Still, it sounds like air was still in the system. The straight six can easily be damaged by going into the red, I do not know if the same is true for the 4-banger.

Did you use the standard thickness HG? that is crucial. Was the head planed to ensure its perfectly flat? You used brand new head bolts? and followed factory torque sequence.

Also the cooling when driving sounds like a bad water pump or thermostat that is not operating properly. Don't ever let you engine go anywhere near the red, shut it down, get it towed home if possible. People 'limp' their straight six home and just ruin the head (cracked/warped).

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Welcome to the forum!

The thickness of the gasket is the standard thickness, yes, new bolts factory torque sequence.
I also realized now that when i open the cooler’s cap i have no water coming in from the return..im starting to think that my new water pump is the problem.
I also put the cooling system under pressure when hot and i went to 1.5bar and it fell to 1.0 bar which is not normal, i saw no leaks…im confused and frustrated. This weekend i might take the water pump out to check.

If anyone has any other out of the box ideas please help lol

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The thickness of the gasket is the standard thickness, yes, new bolts factory torque sequence.
I also realized now that when i open the cooler’s cap i have no water coming in from the return..im starting to think that my new water pump is the problem.
I also put the cooling system under pressure when hot and i went to 1.5bar and it fell to 1.0 bar which is not normal, i saw no leaks…im confused and frustrated. This weekend i might take the water pump out to check.

If anyone has any other out of the box ideas please help lol

Head was not resurfaced because my old gasket didnt blow, i just changed it since i redid all the gaskets and had the engine out

[bluptgm3]

Any sign of ‘milkshake’ (coolant in oil)?
Any sign of oil in the coolant?

Sounds like air in the system.

[OreoE36]

Any sign of ‘milkshake’ (coolant in oil)?
Any sign of oil in the coolant?

Sounds like air in the system.

Nope, no sign of the two mixing.
It can’t be air in the system, i know these cars i’ve bled them hundreds of times.
No air comes out until the car starts to overheat, then air comes out but it doesnt stop which to me is just pressure from somewhere…maybe my head gasket is bad or i did something wrong when i put it on…i just want to rule out everything else before i take the head out again :/

[Eric93se]

Just to point out another potential problem when doing a HG and thats getting a small amount of fluid in the HG bolt holes, this prevents the head from achieving torque. Blowing out all the holes is crucial.

Hope you figure it out and keep us posted.