vacuum

[mustangturbo50]

Ok yesterday i have had my first problem with my car. the oil light flashes and dims in and out when the car is idling, almost as if it is loosing oil pressure, now i have not put a manual gage on it yet but im guessing thats the problem. But the good news is today it did'nt do it. but the thing that bothers me is when i putted my dipstick tube out to check the oil it idled up really high and when i put it back in it goes to normal. This is a sure sign of a vacuum leak. Now what would cause it to have a leak that low down. if anyone can help, let me know. thanks

 

[mustangturbo50]

ok i did the manual gage thing and it has good oil pressure.

 

[Big Daddy]

BMW's have a closed system, removing the dipstick will cause a change in the RPM's, this is normal.

 

[mustangturbo50]

ok well what do you think is causing my high end problem. if i floor it it has a huge power loss off the line but then pulls liek hell from 2500 rmp and up to 6500, but when it goes into liek 3rd sometime 2nd gear it will be reving and then you can actually here it loose power , it boggs out as if it is running out of fuel , leaning out. but i have check for vacuum leaks and have found none. the only code i have is bank one sensor 2 o2 code. would this o2 sensor cause this?

 

[mustangturbo50]

i mean it literally feels like i let off the gas, its that much of a power loss.

 

[Big Daddy]

Oxygen sensors read the fuel mixture in the exhaust and send the information to the computer. The computer then adjusts the fuel mixture. By not replacing faulty oxygen sensors, you can expect that your check engine light will eventually come on accompanied by erratic idle and poor running. Your car probably will not quit running but there could be damage to the catalytic converter.


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[mustangturbo50]

yeah i know all this, but it is just such a dramatic loss of power at high end. i have had alot of cars with o2 sensor problems at my work and i guess i have just never seen symptoms like this. it just seems odd. would a o2 delete work? you know i have seen these symptoms with a clogged cat but its normally all the time. and i read a guy on here was taking his cat off, is that even benificial or is it a waist of time?

 

[Doughnut]

I'd recommend replacing your o2 sensor as this is more than likely one of your problems anyway.
Fix the easy stuff first.
Whats your air and fuel filter like? been replaced recently?

 

[Kirby]

Replace the O2 sensor if you are getting codes. It screws the ECU air/fuel calculations and you can't troubleshoot anything until the ECU is providing proper air/fuel ratio. If you take the Cat off, it will also screw the ECU since you have post cat O2 sensors. You will need an O2 simulator if you pull the cat, and you will still get occasional Check lights.

High speed bogging from leaning out can be caused by many things:
- dirty/clogged fuel
- low fuel pressure (bad fuel pump or regulator)
- bad/worn/wrong spark plugs (i.e. Bosch Platinums are frequently a problem in some BMWs)

Bottom line - a complete tune up is in order. If you still have issues, then look deeper.

 

[mustangturbo50]

it has a cold air on it and its a k@n its brand new and so is the fuel filter. well ill get them replaces, should i just throw some dealer ones on it or do you recomend somthign else for sensors?

 

[Kirby]

I get mine from Autohausaz.com or Autozone. Believe it or not, Autozone seems to have really good prices on Bosch O2 sensors. They usually are cheaper than the dealer, and it is usually the same part made by Bosch. If they list two, one OEM and one generic, this is the type of connector, not the sensor itself. Get the OEM, the generic comes with no connector and you will have to cut and splice wires but save only a few bucks.

 

[mustangturbo50]

ok ill get them tonight and put them on and let ya know. thanks

 

[Doughnut]

ok ill get them tonight and put them on and let ya know. thanks

Cool, see how you go