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Discussion Starter #1
Hey guys, i was wondering how to check if the oxygen sensor on my 633csi is working properly.
thanks
 

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Tell us what's going on..is the light constant, or interminttent..are you having any engine probs?? Feed us info.. :thumbs
 

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Discussion Starter #3
I read in another forum that a faulty 02 sensor can contribute to low gas milage, My car isn't doing to well in that department so i was thinking of checking the sensor.
 

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Originally posted by 633csi@Jul 30 2003, 09:00 PM
I read in another forum that a faulty 02 sensor can contribute to low gas milage, My car isn't doing to well in that department so i was thinking of checking the sensor.
Ya only if your 02 light shows up..if it doesn't, then it's cool!! How many miles since you changed the plugs??
 

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Discussion Starter #6
it has been a while since the plugs have been changed, i just checked them yesterday and they were pretty bad. I am going to replace them, but im sitll just wondering how or if there is away to check the o2 sensor to see if it is comtributing to the problem. No the light isn't on, but in the link you sent me it said they get worse with age and i own an 83.
 

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Originally posted by 633csi@Jul 31 2003, 04:46 PM
it has been a while since the plugs have been changed, i just checked them yesterday and they were pretty bad. I am going to replace them, but im sitll just wondering how or if there is away to check the o2 sensor to see if it is comtributing to the problem. No the light isn't on, but in the link you sent me it said they get worse with age and i own an 83.
Have the dealer hook a dynostic check on the OBC..hmm 83?? Not sure on your ride's OBC but you could have a dealer look at it..
 

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:banghead
I'm new to BMW's and I just picked up a 633csi with 146k on the odometer, I to have been having weird gas mileage I get roughly 280 miles per tank and thats putting in 15gallons, I replaced the plugs with 6 bosch 4prong platinum spark plugs and also got premium bosch plug wires, replaced those and now it seems that my car is harder to start in the cold then it was before..... And I've also noticed a oil leak its strange.... It looses about 1/2 a quart over a weeks time tops, it doesn't BURN oil and it doesn't smoke out the exhaust..... I had a friend look at it and the leak is coming off the back of the engine..... SO What we believe is its a head gasket of somesort my big question is..... if we have to replace the head gasket what all will have to be taken out? Does the fan assembly need to be removed to remove the head? I would really like to get some advice... I also picked up a Chilton for the 633 so i'm planning on reading about that today.... But also while i've found a guy with a similar car to me 633csi have you had any problems with your electronic seats? I picked up my CSI for 1800 bucks only things wrong with it is the head gasket the passanger seat and the sun ruff doesn't open no noise or anything from the engine so we think it may be the switch but ANY help would be a big help so thnx! :)
EvoX
 

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one other way to know if your O2 sensor is bad w/o computer assistance, is if you notice poor gas mileage, high or high irregular idle. before you do anything check and make sure your air box is closed and their are no leaks in the box or hose to the engine, also make sure your filter is in tact.

i have seen instances where a disconnected hose can cause the sensor to mis-register.

good luck
 

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o2 sensor readings.


You can check it on your diagnostic plug though.

Use a VOM on pin 15.

.6 volts is dang rich .3 volts is dang lean.

http://www.kemparts.com/TechTalk/tt07.asp




http://www.unofficialbmw.com/images/reset1.gif


1. Ground
4. Temperature sensor
7. Reset
8. TDC sensor yellow
9. TDC sensor shield
10.TDC sensor black
11.Start signal
12.Alternator charging excitation voltage
13.Ignition coil
14.Alternator charging supply current
15.Oxygen sensor output to test with.


Later,
 
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