[Debaser]

2008 328i. About 90k miles. Regular maintenance performed.

Noticed a loud, consistent, constant "vacuum cleaner" type noise from under the hood about a week ago. I've heard something similar when driving during hot days, but this noise appears even during short night drives now.

Popped the hood just a moment ago. I confess to not know a thing about the mechanics of the car, but I did notice a very large, fast-moving airflow being emitted from both sides of the engine - particularly the right side.

Any obvious diagnoses? Should I be concerned?

Thanks so much in advance.

[94marcus]

I have the same thing except only when I have the ac on.

[Tim603]

Is your engine fan really loud? May be a cooling issue (ie. Water pump/ T Stat going out)

[Debaser]

Was the water pump and thermostat. Replaced.

Thanks, guys.

[94marcus]

Originally Posted by Tim603

Is your engine fan really loud? May be a cooling issue (ie. Water pump/ T Stat going out)

should I be worried since its only when I turn the ac on?

[dtea604]

Its starting to die on you. Had the same problem awhile back. I would get it replaced before the winter. Tischer/getbmwparts.com carrys a kit . Your going to need new coolant as well. Parts alone will be around 500 and labour will be at least a 2-3hr job.

[e90pilot]

Originally Posted by 94marcus

should I be worried since its only when I turn the ac on?

I had this issue on my 325 when it was brand new. It turned out to be the refrigerant pressure. When it's low the compressor makes noise and a bunch came from the factory with low pressure. There's a TSB for early build 325s. A recharge might solve the problem.

FYI, the AC compressor lasts quite a while. Mine died at almost 200k mi. It was $600 installed. Just before it died it would stop working randomly and would start again once I turned it on and off again.

[94marcus]

Originally Posted by e90pilot

I had this issue on my 325 when it was brand new. It turned out to be the refrigerant pressure. When it's low the compressor makes noise and a bunch came from the factory with low pressure. There's a TSB for early build 325s. A recharge might solve the problem.

FYI, the AC compressor lasts quite a while. Mine died at almost 200k mi. It was $600 installed. Just before it died it would stop working randomly and would start again once I turned it on and off again.

what would you say is the best course of action to take cause I have after market warranty on the engine???

edit: sorry didn't read all of it before