Seized Lambda Sensor! Help!
Discussion
Hi all
Quick question.
I need to replace one of the rear lambda sensors on my 2003 STR.
I can get to it and put quite a bit of force into the special (Draper claw foot) tool.
But it's rusted in and I was worried I'd tear the exhaust or round off the hex.
So, should I take it to the local garaged (trusted) or do you have experience of this and have a soloution I can try.
I did think of applying heat, but only have a plumbers blow-lamp type burner.
I'm thinking I may need to drop the exhaust (drivers side) and then attack it, but this looks difficult also.
So any advice gratfully accepted.
The thing is, I've just changed the rear sensor on my other car (same fault code exactly) and it came out easy, (but higher up and better protected).
Quick question.
I need to replace one of the rear lambda sensors on my 2003 STR.
I can get to it and put quite a bit of force into the special (Draper claw foot) tool.
But it's rusted in and I was worried I'd tear the exhaust or round off the hex.
So, should I take it to the local garaged (trusted) or do you have experience of this and have a soloution I can try.
I did think of applying heat, but only have a plumbers blow-lamp type burner.
I'm thinking I may need to drop the exhaust (drivers side) and then attack it, but this looks difficult also.
So any advice gratfully accepted.
The thing is, I've just changed the rear sensor on my other car (same fault code exactly) and it came out easy, (but higher up and better protected).
Years too late but take a look on YouTube. The problem is that the iron-oxide holding the sensor in seems to be black iron oxide Fe3O4. The problem with the black iron oxide is that it does not get smaller when heated. On the other hand, red iron oxide or rust (actually a hydroxide I think) does get smaller when heated to red heat. Rust is supposedly Fe3OH.n where n is the large number of OHs hanging onto the iron. The heat decomposes these and turns the red-rust into the much smaller black oxide. My chemistry might be slightly incorrect but I think you'll get the drift.
Of course when one has that pesky black oxide that doesn't go smaller when heated its a real pain. There are now two or three approaches to the job. (1) If one wishes to save the sensor the job is harder but one can use a slotted-socket and a long breaker bar, one at least two feet long. If one has a friend who has oxy-acetylene the trick is to run the torch in a circle AROUND the sensor. The object of the exercise is to expand the manifold WITHOUT expanding the sensor. This might work.
(2) The second method is to destroy the sensor. First one cuts-off the wires, next one snaps off the extended neck or cover. It should now be possible to get a 22 mm six sided deep impact socket onto the remains of the sensor. On no account use a 3/8" socket set for this job. 1/2" drive is really the minimum that should be used and 3/4" drive is better! On a 19 year old car that has done 122,000 miles one may still need the friend with the oxy-acetylene!
It is worth buying a few special tools for this not so easy job as there are reports of garages charging well over £250 to replace a sensor. Of course when the punter's car is running rich and returning less than 20 mpg they've got him over a barrel if he cannot fix it himself or use a spare car. Good luck!
There is yet another way of collapsing seized and sheared-off bolts. One centre punches the broken stump and drills it until the core of the bolt is almost gone. Next one gets a junior hacksaw blade, preferably a good one made in Sheffield, and wraps tape around it to make a handle. Three small cuts are then made and the remains of the bolt can then be collapsed inwards with a hammer and punch. The three tiny cuts in the female threads are not usually detrimental and the method never fails.
Of course when one has that pesky black oxide that doesn't go smaller when heated its a real pain. There are now two or three approaches to the job. (1) If one wishes to save the sensor the job is harder but one can use a slotted-socket and a long breaker bar, one at least two feet long. If one has a friend who has oxy-acetylene the trick is to run the torch in a circle AROUND the sensor. The object of the exercise is to expand the manifold WITHOUT expanding the sensor. This might work.
(2) The second method is to destroy the sensor. First one cuts-off the wires, next one snaps off the extended neck or cover. It should now be possible to get a 22 mm six sided deep impact socket onto the remains of the sensor. On no account use a 3/8" socket set for this job. 1/2" drive is really the minimum that should be used and 3/4" drive is better! On a 19 year old car that has done 122,000 miles one may still need the friend with the oxy-acetylene!
It is worth buying a few special tools for this not so easy job as there are reports of garages charging well over £250 to replace a sensor. Of course when the punter's car is running rich and returning less than 20 mpg they've got him over a barrel if he cannot fix it himself or use a spare car. Good luck!
There is yet another way of collapsing seized and sheared-off bolts. One centre punches the broken stump and drills it until the core of the bolt is almost gone. Next one gets a junior hacksaw blade, preferably a good one made in Sheffield, and wraps tape around it to make a handle. Three small cuts are then made and the remains of the bolt can then be collapsed inwards with a hammer and punch. The three tiny cuts in the female threads are not usually detrimental and the method never fails.
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