Do not solder O2 sensor wires!!!
05-02-2009, 08:09 AM
#46
If you know how to properly solder then it's fine to do as long as you solder as far away from the O2 sensor as possible(at least 12" away). If done properly it will not add to the resistance of the wire anymore then a crimp connectoror or a plug, chances are it will have less resistance. I learned to solder when I was 8 years old and have seen way more crimp connections fail then I have seen good solder connections fail....come to think of it, I have never seen a good solder connection fail.
Mark
05-03-2009, 06:18 AM
#48
Three Wheelin'
I've always soldered these connections and have not experienced any issues to date. Personally I place more faith in the continuity and physical integrity of a soldered (& heat-shrinked) connection than a crimped connection particularly your average "home" crimped connection which may not be performed with a quality tool, correct gauge of wire or an appropriate weather seal.
05-03-2009, 08:01 AM
#49
Drifting
Join Date: May 2008
Location: Virginia Beach, VA
Posts: 2,080
Likes: 0
Received 15 Likes
on
11 Posts
Just FYI as to Porsche's Point of view on this, We as technicians are directed on all "High importantnce" Connections such as airbag, ABS etc to crimp using there special crimping tool where the crimp grabs the wire and grabs the insulation for support. Porsche's view is that 1. soldering is too inconsistant from one tech to the other... I have seen somone heat the two ends individaully apply solder stick them together and reheat to flow the solder, I have seen his joints break on occasion. 2. As was said above a change in resistance in the circuit, may not be SO important in the 944 series but in the newer cars this is HUGE.
Mark
Mark
Crimp connectors have less surface area contact than a soldered joint, are prone to mechanical failure and will deteriorate faster (corrosion, moisture infiltration, etc). Crimp connectors have their place - mostly for termination. I prefer a crimp/solder termination if possible using crimping dies specific for the connector.
However, I would not recommend soldering O2 connectors, but then again - I wouldn't recommend using a O2 that didn't have the proper termination to begin with.
05-06-2009, 04:12 PM
#50
Burning Brakes
Let's be realistic here. Crimp connectors are specified for repair for monetary purposes. Between training technicians how to correctly solder and the time it takes to do a proper solder joint, it is much more cost effective to just use crimp connectors. Any monkey can crimp a connector. And many FSM call for soldering as a primary repair, with a crimp connection as a acceptable alternative.
Crimp connectors have less surface area contact than a soldered joint, are prone to mechanical failure and will deteriorate faster (corrosion, moisture infiltration, etc). Crimp connectors have their place - mostly for termination. I prefer a crimp/solder termination if possible using crimping dies specific for the connector.
However, I would not recommend soldering O2 connectors, but then again - I wouldn't recommend using a O2 that didn't have the proper termination to begin with.
Crimp connectors have less surface area contact than a soldered joint, are prone to mechanical failure and will deteriorate faster (corrosion, moisture infiltration, etc). Crimp connectors have their place - mostly for termination. I prefer a crimp/solder termination if possible using crimping dies specific for the connector.
However, I would not recommend soldering O2 connectors, but then again - I wouldn't recommend using a O2 that didn't have the proper termination to begin with.
As a 10-year amateur radio operator (working on surface mount electronics and RF antennas/coax/tuners) and user of common sense, I can't believe anyone would advocate a crimp connector over properly applied solder (and, if required, support). Ever try crimp connecting headphone wires? They use a very low energy signal as well ... they must be soldered, and no soldered connection has failed on any of my repairs because I account for stress points when I reassemble (and they receive real-world testing when I go running with them, and that's more stress than a secured O2 sensor wire would ever see).
Those arguing that impedance will be significantly affected by using solder--I'd appreciate seeing your quantitative reasoning. I have a spare O2 sensor and multimeter good to .01 ohm. Perhaps I should hack it up and see ...
Besides, the O2 sensor in a 951 is so inaccurate/imprecise. You watch it on an A/F gauge and it's swinging wildly out of range constantly even when you've got the car at operating temp and a new sensor in place. The best the computer can do is average out the signals and get a general idea of what's going on.
05-06-2009, 05:18 PM
#51
Still plays with cars.
Lifetime Rennlist
Member
John, as far as I know, solid wires are verboten on boats and aircraft since they fail due to vibration. I doubt that we'd find solid wires as OEM in a car either.
Regards,
05-06-2009, 05:39 PM
#52
Addict
Rennlist Member
Rennlist Member
Join Date: Feb 2002
Posts: 5,384
Likes: 0
Received 0 Likes
on
0 Posts
Besides, the O2 sensor in a 951 is so inaccurate/imprecise. You watch it on an A/F gauge and it's swinging wildly out of range constantly even when you've got the car at operating temp and a new sensor in place. The best the computer can do is average out the signals and get a general idea of what's going on.
That is called dithering and the computer is making the AFR swing around 1.0 lamda.
FR Wilk site has a nice explanation: http://the944.com/lambda.htm
05-06-2009, 05:44 PM
#53
Addict
Rennlist Member
Rennlist
Site Sponsor
Rennlist Member
Rennlist
Site Sponsor
Thread Starter
There is a good post on this forum describing WHY the O2 sensor wires should not be soldered. In summary, the O2 sensor uses the area between the core and the insulation to sample outside air/O2.
Do a search and you'll understand how it all works together.
Of course, you can always fork up the extra $ and get the factory O2 sensor and not have to worry about any of this!
Do a search and you'll understand how it all works together.
Of course, you can always fork up the extra $ and get the factory O2 sensor and not have to worry about any of this!
05-06-2009, 06:12 PM
#54
Burning Brakes
There is a good post on this forum describing WHY the O2 sensor wires should not be soldered. In summary, the O2 sensor uses the area between the core and the insulation to sample outside air/O2.
Do a search and you'll understand how it all works together.
Of course, you can always fork up the extra $ and get the factory O2 sensor and not have to worry about any of this!
Do a search and you'll understand how it all works together.
Of course, you can always fork up the extra $ and get the factory O2 sensor and not have to worry about any of this!
05-06-2009, 06:38 PM
#55
Burning Brakes
That is called dithering and the computer is making the AFR swing around 1.0 lamda.
FR Wilk site has a nice explanation: http://the944.com/lambda.htm
FR Wilk site has a nice explanation: http://the944.com/lambda.htm
05-06-2009, 07:29 PM
#56
Addict
Rennlist Member
Rennlist
Site Sponsor
Rennlist Member
Rennlist
Site Sponsor
Thread Starter
05-06-2009, 08:47 PM
#58
Addict
Rennlist Member
Rennlist
Site Sponsor
Rennlist Member
Rennlist
Site Sponsor
Thread Starter
05-06-2009, 08:51 PM
#59
Race Director
BTW...all is good! I have been crazy busy, but it is in Gabe's hands now. Thanks for the quick ship, John.
I'll have a thread about it all very, very soon.
Sorry for the OT guys....
I'll have a thread about it all very, very soon.
Sorry for the OT guys....
05-06-2009, 08:58 PM
#60
Addict
Rennlist Member
Rennlist
Site Sponsor
Rennlist Member
Rennlist
Site Sponsor
Thread Starter