busted o2 sensor

#1

During an enduro race a few weeks ago (crap - I still need to type up a narrative on that one…) my check engine light popped on. Upon subsequent investigation, it turns out that my o2 sensor broke in half, which caused the fault to come up.

Looking at it last night, it didn’t look like there is much if anything in the way of threads in the manifold to screw the sensor into, which has me more than a bit perplexed. From the looks of it, it also didn’t appear that the non-attached half was in the hole, which makes me think that it must have blown out the tailpipe.

Does anyone happen to have pictures of what the o2 sensor should look like, and also (I know this is stretching it) a close-up of the hole in the manifold that it screws into? And I assume that it is simply a hole - I’m almost wondering if what appears to be part of the sensor actually may have broken off of the manifold. The Bentley manual was pretty useless on this. I’m 99% sure that the o2 sensor is dead, but am perplexed as to how this thing attaches, as silly as that sounds… :frowning: Help!!! Aaaaargh!

Steve

#2

https://www.automedicsupply.com/showpicture.php?&sensor=15736

The bosch sensor in the above link is like the one in your car- but the tip is covered with protective plastic cover…You can see a different type in the upper left of that page- it’s similar to the bosch sensor in your car- but the tip is not perforated like that one, it’s sort of crimped with 5-6 indentations in the tip running along the length of the tip.

Hope this helps- the hole in the pipe is just a threaded port- should have 4-6 threads in it.

Here’s a Pelican Parts tech article on E30 O2 sensor replacement- still no pic of the sensor hole…

http://www.pelicanparts.com/BMW/techarticles/E30-O2_Sensor/E30-O2_Sensor.htm

Bret.

Post edited by: rigmaster, at: 2006/05/03 20:30

#3

Thanks much! The only pictures I was able to find showed sensors with the plastic covering on them, which made them less than helpful! It looks like the part with the threads are part of what broke off on mine. I’ll check again tonight - there must be some threads on the socket.

Has anyone else heard of this happening? It was during an enduro, so it was hot for quite a while, but the engine oil temp never got any hotter than in the past…

Steve

#4

I can get pics of this tonight since my exhaust is on the ground and my O2 sensor is on a shelf.
cheers,
bruce

#5

Well, the new sensor came in the mail yesterday. As pictured (thanks Bruce), it of course has threads - something that the old sensor is now without. I stuck my finger in the hole on the downpipe, and as I’d remembered it is completely smooth - no threads, no lines, no ripples, nothing. I guess the solution is going to require replacing the downpipe. A little more work that I’d hoped for, but still doable.

Any ideas on what might have caused this? Literally, both the o2 sensor and the mounting flange have had their treads completely worn or melted or rubbed off. :huh: :huh: :huh:

#6

Was there any sign of rusting on the hole or the sensor? Was there a previous owner? Maybe the threads got stripped to hell.

There’s no way it melted. If the exhaust gas was that hot, your pistons and valves would be blobs by now.

#7

Is the bung still there?
http://images.google.com/images?q=O2+bung+&svnum=10&hl=en&lr=&safe=active&start=20&sa=N

#8

heh

you said bung!

Beavis

#9

FARTBREF wrote:

[quote]heh

you said bung!

Beavis[/quote]
I laughed when I typed it
Bungs are cool
Heh Heh

Butthead

Post edited by: nasaregistrar, at: 2006/05/17 06:01

#10

Steve,

Unless the down pipe is trashed, why not have a muffler shop cut off the old bung and weld on a new one? Would be a good, cheap fix.

Ed

#11

edavidson wrote:

[quote]Steve,

Unless the down pipe is trashed, why not have a muffler shop cut off the old bung and weld on a new one? Would be a good, cheap fix.

Ed[/quote]

That’s exactly what I was thinking. However, I’m a little bit worried that if I walk into a muffler shop and ask "do you sell bungs here?" I’m either going to get (a) my ass kicked or (b) put in jail for solicitation. :woohoo:

Actually, I thought I’d posted a response to that effect yesterday evening, but must not have hit the ‘submit’ button. Oops.

#12

Or you could order a bung from JEGs and take it to the muffler shop and ask them to repair your "O2 sensor fitting" (actually your broken bung) that way you don’t have to risk the consequences of use of the common term. However, don’t be suprised if they say " you mean your "b@#$?"