N52 3.0si Lambda Voltages/Adaptions

[LBN]

Hi everyone,

My E86 has developed a bit of a hiss under acceleration which suggests a vacuum leak. Having checked my lambda readings on my OBD reader I’m getting these figures:



I’m struggling to make head or tail of these numbers. From what I’ve read, this seems to mean I’m running rich. Is this correct? If so, how rich am I running? No codes have been thrown up yet.

I’m going to have my mechanic check it out when the MOT is due in a couple of weeks.

 

[DashingDaryl]

I would focus on the hiss first. Once you fix that, the readings should get back to normal since your z won't have an unregulated air intake

Kinda weird you don't have a check engine light though.

 

[LBN]

I would focus on the hiss first. Once you fix that, the readings should get back to normal since your z won't have an unregulated air intake

Kinda weird you don't have a check engine light though.

It can’t be very big, as it’s not thrown any codes. When you mention normal numbers, what sort of adaptions and voltages are considered normal?

 

[enuff_zed]

Colb has explained this on several threads. If you have an air leak after the MAF then the engine thinks it is running weak and pumps in more fuel, richening the mixture.
Find the air leak first and it should hopefully sort your readings out. At the moment they are correctly diagnosing your fault for you.

 

[LBN]

Colb has explained this on several threads. If you have an air leak after the MAF then the engine thinks it is running weak and pumps in more fuel, richening the mixture.
Find the air leak first and it should hopefully sort your readings out. At the moment they are correctly diagnosing your fault for you.

Yeah, I've read those. I want to get a comparison to the baseline of what the adaptions should be so I can make a decision on how bad the fault is, and whether or not I carry on driving it regularly for the couple of weeks until I take it over to my mechanic.

 

[enuff_zed]

Colb has explained this on several threads. If you have an air leak after the MAF then the engine thinks it is running weak and pumps in more fuel, richening the mixture.
Find the air leak first and it should hopefully sort your readings out. At the moment they are correctly diagnosing your fault for you.

Yeah, I've read those. I want to get a comparison to the baseline of what the adaptions should be so I can make a decision on how bad the fault is, and whether or not I carry on driving it regularly for the couple of weeks until I take it over to my mechanic.

To be honest, pop the bonnet, get it running and listen around for the hiss. you may well find it's a simple fix. Or even a split hose will run better with a bit of tape round it until your mechanic can sort it.

 

[LBN]

So, I’ve had my mechanic check things out while I had the car MOT’d today.

The main noise I had actually been hearing was a bit of a wonky alternator bearing/pulley which I can live with as it isn’t causing any harm. This noise has been persistent, while my idle issues have been very inconsistent so I should have realised the difference.

In terms of a vacuum leak, there was a small hissing noise coming from the brake servo of all places, which shares vacuum with the intake, which appears to be the source of my problems. However by the time I’d come to collect the car, that leak wasn’t making any noise anymore!

I think it’s going to be a bit of a little quirk of my car in particular for the moment, if my idle issues get more consistent I’ll at least know where to look.