Overheating of the BMW 335d M57

[IrvesBMW]

Hello everyone, I recently replaced the water pump and thermostat on my 2007 335d m57. The expansion tank was bubbling over. I also conducted a CO2 test in the expansion tank, but the die remained blue, indicating that the head gasket was not the issue. I then filled the tank with new coolant and bled the system. Unfortunately, I had to do this manually because I have a mechanical pump. I drove the car until it reached warm temperature and everything appeared to be fine. However, when I returned from a 5-minute drive, I noticed that the top hose had solidified again. When I opened the expansion tank, it erupted like a volcano. Therefore, my next step is to replace the radiator. Any assistance would be greatly appreciated.

[TDudette]

An airlock occurs when a hose becomes rigid, and it may be caused by factors such as a head gasket. Although it is very uncommon, it can nonetheless occur.

[VWDaveBMW]

To remove the remaining air, I leave it running for 30 minutes while removing the cap.
In the past, I have even engaged in a run while removing the cap and carrying a container of coolant on a malfunctioning vehicle.

[TDudette]

Have you included any gasket seals, such as a K-seal or similar,?

[IrvesBMW]

Hi no I haven't put any head gasket stuff in as I'm sure it's not the head gasket I don't have any head gasket symptoms and also done a test woth the blue dye and the dye stays blue also no oil in coolant, my oil isn't milky no loss of compression no fluid or excessive smoke from exhaust, I did put new radiator on last night took for a 10 min run amd top hose was fine and no back pressure from expansion tank, so took for another run but gave it a good booting and top hose went hard again, forgot to mention its running stage 2 tune, egr delete,dpf delete upgrade intercooler its running 370 bhp so would that cause my problem, thanks

[TDudette]

However, at what point was it remapped? By whom?

[IrvesBMW]

I am uncertain about the origin of the vehicle, as I acquired it from a friend. However, I allowed it to undergo a tickover process for a duration of three hours, specifically from 1pm to 4pm. During this time, the top hose exhibited a pleasant and pliable quality, while the expansion tank did not experience any back pressure. Consequently, the vehicle's performance deteriorated upon a thorough booting. In light of this, I have requested my friend, who is responsible for arranging a 330d e90, to arrive later so that we can conduct a similar booting procedure. I will provide you with an update at a later time. Thank you for your responses.

[TDudette]

Is it excessively heating? Furthermore, excessive heating may cause the head, gasket, and other components to distort.

[IrvesBMW]

The temperature on the hidden menu does not exceed 90 degrees, and there is no loss of coolant. Additionally, I did not complete my job until 7.30 yesterday night, so I did not have the opportunity to visit my colleague to see whether his 330d also has the same issue

[TDudette]

Sounds satisfactory to me, I am certain in that.

[jennycarlotta]

As the temperature increases, the coolant system undergoes pressurisation, therefore preventing the coolant from boiling. If there is no excessive heat and no fluid loss, I would recommend that it is OK. For tasks that need a coolant refill, I prefer to use a vaccum filler. This device effectively removes all air from the system and then replenishes it.
Applause.