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Discussion Starter #1
when the oil dipstick was plugged and unplugged when the engine is idled. Noticed the short-term fuel trim is getting too lean when the dipstick is removed.



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Nothing wrong here. When you remove the dipstick you’re creating a vacuum leak which would cause a lean fuel trim.
 

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Nothing wrong here. When you remove the dipstick you’re creating a vacuum leak which would cause a lean fuel trim.
Ok. I am wondering if I can drive the car with the dipstick unplug (with the dipstick pop up a little off the tube) for a few days. The theory behind this is I want to see if it will release the pressure in the crankcase and stop the oil leak from the rear main seal.


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I can’t speak to your theory but I know about fuel trims.

I was driving my car for several days with the fuel trims in the high 30. Your CEL will trigger if you go above 25.

it’s generally an idle only issue as when you drive your air will increase and not create a vacuum.
 

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I can’t speak to your theory but I know about fuel trims.

I was driving my car for several days with the fuel trims in the high 30. Your CEL will trigger if you go above 25.

it’s generally an idle only issue as when you drive your air will increase and not create a vacuum.
Question. Does the air always suck in through the oil dipstick tube or the oil will spew out under normal driving conditions?


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You’ll get more vacuum (suction) at idle because the throttle body is mostly closed. Once you start driving the TB will open and allow more air in which create less suction.

I’d imagine you’d get some splatter from the open dipstick.

personally I’d just fix the seal.
 

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My long term fuel trim on bank2 is -7. I have replaced o2 sensors fuel injectors and coils and I can't get it to change to approach zero. Nothing seems to effect it. Bank 1 is roughly -.8, which is excellent. Any ideas what can be done here to bring it more inline. I didn't take measurements before I did the valve adjustments and I wonder if that's my issue. It isn't triggering any fault codes or anything like that, but I guess I was trying to bring it closer to zero
 

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Discussion Starter #9 (Edited)
Driving with dipstick unplugged and notice the fuel trim. After driving with the dipstick unplugged for 7 hours in the city and checked for oil spewing out or splattering, there is none.




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