removing a rusted-in lambda sensor (and other bolts)

[kevinh]

DOES ANYONE HAVE ANY IDEAS ON HOW TO REMOVE THE AWKWARDLY SITED LAMBDA SENSOR?

I recently ran a Forscan diagnostic and found DTCs that implied both the cam position sensor and the lambda sensors were faulty.
Although this might not be the case, I figured it was easiest to just replace them and see if the problems resolved.
Simple enough jobs in theory, until I discovered the extent of rusted bolts on my engine.

For the cam sensor, it took me over two hours to remove the engine cover, since the hex nuts had rusted to the point where they wouldn't bite an allen key. Hammering in a torx bit finally did the trick.
Replacing the cam sensor was then simple, and after clearing the code it hasn't returned (yet )

Trying to remove the covers over the rear exhaust manifold to get at the lambda sensor was worse still.
Out of 10 bolts/screws
2 were missing,
5 came out grudgingly after liberal use of rust remover and WD40 and patience,
2 appeared to be slowly working loose but actually just sheared off
1 was so rusted I couldn't get enough grip no matter what.
This took an entire afternoon of trying things with still 1 left. I resorted to buying a bolt remover kit from Amazon, which arrived next day and thankfully did the job without much trouble.

So, at last, I could get at the sensor to remove it.
Except it's also rusted into place and no matter what I try I cannot get a tool into the limited space to grip it properly.
I even bought a ratchet span with a 180 degree pivoting end, but the pivot makes it too bulky to get down onto the nut from most angles.
I've tried a normal open-ended spanner, but can't get an angle. Tried an adjustable spanner (!) but that barely gets an angle and of course that just slips.
It's been over a week since I started this 'five minute job' and I'm at the point where the only thing I can think of is to try to break the body of the sensor off of its bolt part to see if I can then manage to get a socket onto it.

So, I'm wondering does anybody have any better ideas?
I know I'm not the first person to have to do this and I know you're all used to plenty of rust

 

[st220kyle]

DOES ANYONE HAVE ANY IDEAS ON HOW TO REMOVE THE AWKWARDLY SITED LAMBDA SENSOR?

I recently ran a Forscan diagnostic and found DTCs that implied both the cam position sensor and the lambda sensors were faulty.
Although this might not be the case, I figured it was easiest to just replace them and see if the problems resolved.
Simple enough jobs in theory, until I discovered the extent of rusted bolts on my engine.

For the cam sensor, it took me over two hours to remove the engine cover, since the hex nuts had rusted to the point where they wouldn't bite an allen key. Hammering in a torx bit finally did the trick.
Replacing the cam sensor was then simple, and after clearing the code it hasn't returned (yet )

Trying to remove the covers over the rear exhaust manifold to get at the lambda sensor was worse still.
Out of 10 bolts/screws
2 were missing,
5 came out grudgingly after liberal use of rust remover and WD40 and patience,
2 appeared to be slowly working loose but actually just sheared off
1 was so rusted I couldn't get enough grip no matter what.
This took an entire afternoon of trying things with still 1 left. I resorted to buying a bolt remover kit from Amazon, which arrived next day and thankfully did the job without much trouble.

So, at last, I could get at the sensor to remove it.
Except it's also rusted into place and no matter what I try I cannot get a tool into the limited space to grip it properly.
I even bought a ratchet span with a 180 degree pivoting end, but the pivot makes it too bulky to get down onto the nut from most angles.
I've tried a normal open-ended spanner, but can't get an angle. Tried an adjustable spanner (!) but that barely gets an angle and of course that just slips.
It's been over a week since I started this 'five minute job' and I'm at the point where the only thing I can think of is to try to break the body of the sensor off of its bolt part to see if I can then manage to get a socket onto it.

So, I'm wondering does anybody have any better ideas?
I know I'm not the first person to have to do this and I know you're all used to plenty of rust

I think I've seen someone on here use a ring spanner with a slot cut out of it with success.

I assume you've tried heating the sensor up before attempting to remove it?

 

[DOH]

I have sucessfully removed the lambda with the proper 22m removal tool using the 1/2" drive item with a long 1/2 " socket extension and a power bar (not a ratchet as the handle isn't long enough for the required torque. You can also use a Torque wrench on the socket extension .

The tool I used is like this.

https://www.ebay.co.uk/itm/20452032...yvQzogbxO6AV5XQrq1aL+gXA==|tkp:Bk9SR7TY_sfxYg

 

[kevinh]

I have sucessfully removed the lambda with the proper 22m removal tool using the 1/2" drive item with a long 1/2 " socket extension and a power bar (not a ratchet as the handle isn't long enough for the required torque. You can also use a Torque wrench on the socket extension .

The tool I used is like this.

https://www.ebay.co.uk/itm/20452032...yvQzogbxO6AV5XQrq1aL+gXA==|tkp:Bk9SR7TY_sfxYg

It never occurred to me that I'd have to buy a dedicated tool, even though I had envisaged how something almost exactly like this would solve my problem.
I should have guessed that would be a manufacturer's approach, rather than making it accessible in the first place

Thanks for the tip. I was getting VERY frustrated by this.

 

[kevinh]

I think I've seen someone on here use a ring spanner with a slot cut out of it with success.

I assume you've tried heating the sensor up before attempting to remove it?

I had thought about heating it up but didn't think I have any sort of heater suitable and was too nervous to use anything like a flame.
Only as I read your note did I think that I could perhaps just run the engine....

 

[Sjoerd]

I had thought about heating it up but didn't think I have any sort of heater suitable and was too nervous to use anything like a flame.
Only as I read your note did I think that I could perhaps just run the engine....

And then burn yourself on a hot exhaust. Been there done that.
Best is to just use a special wrench for it with a cut out.
But lots of wd-40, a normal spanner a big hammer, a little bit of anger and mostly patience also does the trick.
If your lambda is broken though, why don't you just disconnect it and see if the given values in Forscan change?

 

[DOH]

It never occurred to me that I'd have to buy a dedicated tool, even though I had envisaged how something almost exactly like this would solve my problem.
I should have guessed that would be a manufacturer's approach, rather than making it accessible in the first place

Thanks for the tip. I was getting VERY frustrated by this.

Buy the tool I recommended as it will fit all Lambda sensors on your future vehicles. Yes removing the Lambda from a hot manifold will be easier. Ignore the advice from Sjoerd, you should never use a spanner and hammer to remove a Lambda sensor! They contain a heater element and are very fragile (like a light bulb) That will break internally from hammering. You also risk rounding off the Lambda's nut.

Has the timing belt recently been replaced as if the valve timing is a few degrees out that can flag a fault code for the camshaft sensor. It will also cause the fuelling to be wrong. So I recommend you explore that avenue of thought.

 

[kevinh]

So, after buying two different sensor removal tools (a tall one with hex on top, and a 'crowfoot' style as suggested above), and getting the engine hot enough that I had to be careful about burns, all I managed to do was chew up the bolt somewhat. No movement at all.
I finally gave up and took it to my local garage which swapped it over and charged me £45 for the job. Probably only took them five minutes and they didn't even need to remove the shields around it (which had caused me no end of grief). I'm beginning to wonder whether I want to bother doing even 'simple' jobs myself in future since I seem to spend all my time just fighting rusted bolts and buying tools I might never use again .
Thanks everyone for your suggestions though.

 

[DOH]

So, after buying two different sensor removal tools (a tall one with hex on top, and a 'crowfoot' style as suggested above), and getting the engine hot enough that I had to be careful about burns, all I managed to do was chew up the bolt somewhat. No movement at all.
I finally gave up and took it to my local garage which swapped it over and charged me £45 for the job. Probably only took them five minutes and they didn't even need to remove the shields around it (which had caused me no end of grief). I'm beginning to wonder whether I want to bother doing even 'simple' jobs myself in future since I seem to spend all my time just fighting rusted bolts and buying tools I might never use again .
Thanks everyone for your suggestions though.

The tool I recommended cant slip as its a hex head (6 sided) tool. So I can only assume you weren't on it straight. In any event their tool will have been similar to one of the two you bought. It's likely it took them more than 5 minutes, in view of your difficulty. Unless you have a long 1/2" drive socket extension with a long power bar or torque wrench , you won't have been able to shift it . The good news is it's now replaced. How is your car running now?

 

[kevinh]

The tool I recommended cant slip as its a hex head (6 sided) tool. So I can only assume you weren't on it straight. In any event their tool will have been similar to one of the two you bought. It's likely it took them more than 5 minutes, in view of your difficulty. Unless you have a long 1/2" drive socket extension with a long power bar or torque wrench , you won't have been able to shift it . The good news is it's now replaced. How is your car running now?

I bought a similar tool to the one you recommended, but from Amazon since I wanted it quicker, and that listing was ended anyway. But I found that I couldn't use it since I don't have a 1/2" wrench of any form and I'd assumed it would be 3/8.
So, I bought another tool, which was of the cylindrical type - ie taller and with a hex 'nut' on the top and a 3/8 square fitting. It actually seemd like it would be more suitable. But that one had a slightly wider slot for the wire and I think that was the problem: It was extremely difficult to keep the tool on straight whilst also trying to apply a lot of torque, and the slot was wide enough that it didn't really hold the sensor's 'nut' firmly enough. I felt that the jaws were actually flexing under the strain and hence it slipped. I will be sending it back as a poor product - it simply needs a narrower slot to make it more rigid.
I would agree that the type of tool you recommended would certainly be more likely to hold firmly, but I couldn't use it without more time and money wasted. :-(

 

[DOH]

The type I recommended had both the 3/8" & 1/2" drives ( 2 separate tools). With the type you currently have purchased. If you had put a jubilee hose clip around the bottom of it , it would have stopped the jaws spreading.

 

[Hugh Jass]

I am very lucky to have a retired mechanic for advice. For my son's Fiesta I hammered a V into the side of the sensor, turned the chisel slightly and got it moving. The car needs to be very secure on its axle stands though. For my Puma I bought a tool which works well for me with a 3 foot power bar and half inch drive.