[Centmaker]

I read somewhere it doesn't turn on immediately in order for the engine to warm up faster from a cold start. Is this true or not? I'm arguing with an arrogant mechanic friend who thought the thermostat is behind the oil filter housing and claimed you have to remove it to get to the thermostat. I was laughing at him and told him that's why regular mechanics mess up bmw's when they try to work on them.

[Centmaker]

Originally Posted by BimmerGeeks

Let him believe that, just don't let him work on your bmw.

Oh I'm not, just trying to find a reference by bmw or something because we have a bet whether or not the water pump turns on immediately.

[Centmaker]

Originally Posted by BimmerGeeks

I can test tomorrow. Will respond.

I tested it earlier today. My car was overheating but it suddenly stopped overheating and drove 300 miles back home with no issues, either something started working again or there was a block in the coolant passages. I turned it on with the reservoir cap off and after about one minute I saw the the stream of coolant at the same time the coolant level rose and spit all the coolant out. Pieces of the plastic floater flew out.

[sunny]

Originally Posted by Centmaker

I read somewhere it doesn't turn on immediately in order for the engine to warm up faster from a cold start. Is this true or not? I'm arguing with an arrogant mechanic friend who thought the thermostat is behind the oil filter housing and claimed you have to remove it to get to the thermostat. I was laughing at him and told him that's why regular mechanics mess up bmw's when they try to work on them.

I have a HUD that connects to obd2 and it also shows water temp.
it seems when the water temp reaches about 220F ish, it starts to go down to about 180F ish and than back to 220F ish. this repeats over and over again.
so I think you can pretty much guess when the thermostat opens and closes and when water pump turns on and off.

[kkasson]

Originally Posted by Centmaker

I read somewhere it doesn't turn on immediately in order for the engine to warm up faster from a cold start. Is this true or not? I'm arguing with an arrogant mechanic friend who thought the thermostat is behind the oil filter housing and claimed you have to remove it to get to the thermostat. I was laughing at him and told him that's why regular mechanics mess up bmw's when they try to work on them.

It may or may not start when the vehicle starts. It depends on the ambient temperature, temperature of the engine, rate at which the engine is heating up, etc.

Google "N52 training pdf" and the top result should be an attachment from this forum. It's a technical training document directly from BMW. See the section around page 54 for a detailed description of the management of the cooling system. It will describe it better than any of us would.

Also, what he may have been referring to is the thermostat inside the oil cooler on the N54/N55. It sounds like he was just wrong, but he may have been confusing the actual thermostat with that thermostat inside the oil cooler.

[NotQuickEnough]

For what it's worth I notice every time when the hot air coming out of the vents gets cooler at a certain point after driving for about 5-10 min

[Wolf 335]

Originally Posted by kkasson

It may or may not start when the vehicle starts. It depends on the ambient temperature, temperature of the engine, rate at which the engine is heating up, etc.

Google "N52 training pdf" and the top result should be an attachment from this forum. It's a technical training document directly from BMW. See the section around page 54 for a detailed description of the management of the cooling system. It will describe it better than any of us would.

Also, what he may have been referring to is the thermostat inside the oil cooler on the N54/N55. It sounds like he was just wrong, but he may have been confusing the actual thermostat with that thermostat inside the oil cooler.

What kkasson said.

[Welcome to NBA Jam]

Originally Posted by Centmaker

I read somewhere it doesn't turn on immediately in order for the engine to warm up faster from a cold start. Is this true or not? I'm arguing with an arrogant mechanic friend who thought the thermostat is behind the oil filter housing and claimed you have to remove it to get to the thermostat. I was laughing at him and told him that's why regular mechanics mess up bmw's when they try to work on them.

- The water pump does immediately circulate coolant, you can literally hear it if you rev the engine

- The thermostat is located behind the water pump, under passenger side of the car

- If you remove the oil filter housing, you will find some large holes for oil and coolant

- Anyone who removes the oil filter housing to get to the thermostat on a BMW is dumb

[John 070]

I've always felt that since 2007, the 335i warms up faster than any car I've ever owned, and that there is heat by the time I reach the end of my driveway, and I don't exactly live at Southfork...this implies to me the water pump did not circulate coolant upon starting...

[Centmaker]

Thanks guys, that's what I was looking for. I won the bet and I told him this is the reason regular mechanics shouldn't touch BMW's because they are arrogant.

[Greyfox]

Okay, some of ya'll lack logic and mechanical knowledge.

Just because the water pump is running does not mean the water is flowing through the engine block. That is why there are valves and recirculating lines.

Coolant will not flow past any thermostat until the operating temperature is reached in the engine. This does not matter whether it's a mechanical, electrical or spring controlled thermostat.

And if you want to screw up an engine, completely bypass or remove the thermostat.

[tlow98]

Originally Posted by Centmaker

Thanks guys, that's what I was looking for. I won the bet and I told him this is the reason regular mechanics shouldn't touch BMW's because they are arrogant.

"Regular" mechanics not being able to work on BMWs? Come on, guys, let's not perpetuate the stereotype of bmw owners being elitists.

Anyone can work on BMWs with training. They're nothing special.

You knew nothing more than this "regular" mechanic. You had a hunch and you had to come here to verify it. If this mechanic spent any time working on or reading about BMWs (your area of expertise) he'd have known better.

You don't know what you don't know.

[Centmaker]

I did the venting procedure (hold gas pedal for 10 seconds with engine off) and watched the stream in the coolant tank and the stream is intermittent. Every three seconds it pumps coolant for about one second. Should this be a continuous stream during the venting procedure or is my water pump going bad? Car is overheating sometimes, but sometimes it's fine.