[greenlight740]

2011 bmw 335xi 133k miles. Replaced radiator, water pump, thermostat, plastic hose that runs on k member, coolant tank and hose on driver side to trans cooler. It seems to be blowing coolant out driver side area once it gets up to temp. Doesn’t over heat seems like there could be a blockage in the system. I just got this car and issue occured on my way home. If I make short trips I have no issues with the car but can’t drive for longer than 20-30 minutes. Any input on this?

[gbalthrop]

Originally Posted by greenlight740

2011 bmw 335xi... It seems to be blowing coolant out driver side area once it gets up to temp...

Coolant Loss due to LEAK in cooling system is dependent upon PRESSURE in ths Cooling System. The system is CLOSED except for leak location. That means that PRESSURE (Vapor Pressure of Coolant) increases with coolant Temperature. Pump operation is NOT a significant factor. Run engine at idle until it gets to ~ 90C normal operating temp. Turn engine OFF.

Vapor Pressure of Coolant will remain due to engine temperature transferring heat to coolant. System will LEAK the SAME or perhaps MORE than if engine were running. You may need to put front wheels on ramps, remove Splash Shield under engine, & locate leak from BENEATH engine.

Many folks believe they need a "Pressure Tester" to physically "Pump Up" pressure in system. That is NOT the case. Why is there a "Pressure CAP" on the Coolant Reservoir? Why is 20 PSIG cap used? Why is max pressure using Tester 1.5 Bar (21.7 PSIG)?
George

[greenlight740]

Originally Posted by gbalthrop

Coolant Loss due to LEAK in cooling system is dependent upon PRESSURE in ths Cooling System. The system is CLOSED except for leak location. That means that PRESSURE (Vapor Pressure of Coolant) increases with coolant Temperature. Pump operation is NOT a significant factor. Run engine at idle until it gets to ~ 90C normal operating temp. Turn engine OFF.

Vapor Pressure of Coolant will remain due to engine temperature transferring heat to coolant. System will LEAK the SAME or perhaps MORE than if engine were running. You may need to put front wheels on ramps, remove Splash Shield under engine, & locate leak from BENEATH engine.

Many folks believe they need a "Pressure Tester" to physically "Pump Up" pressure in system. That is NOT the case. Why is there a "Pressure CAP" on the Coolant Reservoir? Why is 20 PSIG cap used? Why is max pressure using Tester 1.5 Bar (21.7 PSIG)?
George

It won’t leak under a pressure test. Once it heats up it comes out the bleeder screws or around that area.

[Sgop335]

May know the issue. What radiator is used oem or aftermarket?

[greenlight740]

Originally Posted by Sgop335

May know the issue. What radiator is used oem or aftermarket?

Aftermarket from oriellys

[Sgop335]

Originally Posted by greenlight740

Aftermarket from oriellys

What I thought. So here is your very likely issue. The radiator has the wrong drain plug, one for manual.
This is quite an issue because it goes undetected in a pressure test. It leaks when atf comes to temperature and trans cooler opens. This pressurizes above the drain plug where there is no seal due to the incorrect plug. Leak.
Can strand you and overheat the transmission.

[greenlight740]

How do you know if you have right one or where can I get correct one

[GoRomeo]

Originally Posted by greenlight740

How do you know if you have right one or where can I get correct one

You dont cheap around with a radiator. Buy OEM at the dealership. I bought one last year for my E90. Was like $250 I believe? The original lasted me like 16 yrs. Totally worth it.