Position of vacuum line for boost gauge on N52 engine

ProfCJJ · Post by **ProfCJJ** » Tue Jan 01, 2019 9:51 pm

Hi all

I have one of the P3 gauges now fitted to my 2011 E89 sDrive MSport 30i and it works very well showing all sorts of info like temps etc. In order for the boost gauge to work I need to connect up an external sensor (supplied) to the vacuum line near the manifold. I have never worked before on this engine and so would appreciate if anyone knows where I should look (I know, around the manifold!

) to make sure I measure twice and cut once! The kit supplies all the necessary parts like sensor, rubber tubing and T-joint etc. I just need to be sure I am connecting to the correct point for this engine (N52). Any photos etc would be most welcome.

Many thanks

Smartbear · Post by **Smartbear** » Tue Jan 01, 2019 9:58 pm

ProfCJJ wrote: ↑Tue Jan 01, 2019 9:51 pm Hi all

I have one of the P3 gauges now fitted to my 2011 E89 sDrive MSport 30i and it works very well showing all sorts of info like temps etc. In order for the boost gauge to work I need to connect up an external sensor (supplied) to the vacuum line near the manifold. I have never worked before on this engine and so would appreciate if anyone knows where I should look (I know, around the manifold! ) to make sure I measure twice and cut once! The kit supplies all the necessary parts like sensor, rubber tubing and T-joint etc. I just need to be sure I am connecting to the correct point for this engine (N52). Any photos etc would be most welcome.

Many thanks

Hi, do you mean a vacuum gauge as opposed to a boost gauge as the n52 engine isn’t forced induction?

Rob

ProfCJJ · Post by **ProfCJJ** » Tue Jan 01, 2019 10:14 pm

Smartbear wrote: ↑Tue Jan 01, 2019 9:58 pm Hi, do you mean a vacuum gauge as opposed to a boost gauge as the n52 engine isn’t forced induction?
Rob

Hmm! very good point - the gauge is as shown here: http://www.p3cars.com/bmw/bmw-z-series/ ... lti-gauge/ and it states it displays "Boost and Vacuum" ... it does however state that the external sensor is needed for the N54 engine (I understand mine is a N52) that would seem to imply I don't need the external sensor and I can rely on just OBD?! This seems to contradict the paper I received with the kit.

I might have to contact the supplier about that - thanks for making me think about that!!

Thanks

Maniac · Post by **Maniac** » Wed Jan 02, 2019 4:52 pm

I’m not sure why you’d want a vacuum display? Unless you have a vacuum leak?

Boost is a different matter and for that you’d need a turbo’d Car.

noiseboy72 · Post by **noiseboy72** » Wed Jan 02, 2019 9:55 pm

Vacuum is useful from an economy point of view, but it doesn't give you much in the way of diagnostic information or performance. As soon as you open the throttle more than 30%, the vacuum will drop to pretty much zero in any case

ProfCJJ · Post by **ProfCJJ** » Thu Jan 03, 2019 2:49 pm

Thanks for the replies - I was only fitting it for completeness' sake. Turns out of course its not needed for my engine anyway. I pointed out the error to the manufacturer and they will put it right - it was a "copy and paste" error.

Thanks for all the info all - I learn something new every day here

Best

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