Technical Siezed O2 Sensor

[Goudrons]

The problem with most ring spanners and some sockets is they have too many corners for the nut.
It's so you can fit the spanner on nuts at various degrees.

If you look at the image in the link you can see it's like a star rather than nut shaped.

108-36 | SAM No, No Slogging Spanner, 36 mm | RS

uk.rs-online.com

This means you're not gripping the nut properly, it's just catching on to the corners of the nuts flats and not contacting all of the nut.
With these type spanners/sockets there is a high chance the thing slips and rounds off the head on the nut/bolt if it's tight.

This is ok for most smaller nuts and bolts that's don't usually get fitted so tight but anything that's big and tight needs a proper fitting spanner or socket that fits the nut head completely, like https://www.screwfix.com/p/hilka-pr...ch/2369r#product_additional_details_container

As you can see it has just six flats, same as the nut so it fits better so you can apply the torque required to get it moving.

Same thing for an open ended spanner, you're contacting just a third of the nuts surface, not all of it.

Even if you start to round a nut off with the wrong type spanner you can often still get it to move by using the six sider as it doesn't just utilise the nut corners to grip the nut, which is why I wrote you need the right tool and linked to it.

For future reference, small nuts and bolts upto around a M6 (13mm spanner) are usually ok with a star type spanner/socket as they are only usually tightened to 12-18nm.
When the bolt/nut size increases the torque on them rises exponentially.
So a M12 doesn't just handle double an M6 (24-36nm) but usually handles 250-400nm.

 

[Pugglt Auld Jock]

It's worth mentioning Freeze and release sprays. Like this one which I have used with great success: https://www.arco.co.uk/Web-Taxonomy...-and-Release-Spray-400ml/p/PIMM00000000032351 There are others on the market: https://www.screwfix.com/p/arctic-p...0eCSerKivpGNjzi_7uQaAgraEALw_wcB&gclsrc=aw.ds but I have only ever used the loctite product - 'cos that's what my supplier sells and because I like loctite stuff generally.

You do need to apply quite a lot of the spray for it to chill the work properly and you need to think intelligently about where you are spraying it - remembering it shrinks things so if you spray it mainly on the "wrong" part you'll increase the seizing problem, although the very fact it causes things to shrink and expand again when you stop spraying is going to tend to crack off the corrosion. I find I never use less than about a third of a can for it to be effective.

It can also be highly effective if you hit the problem with some of this, then heat it up with a blow torch and hit it with the spray again. Be a bit careful if you try this as you need to let things cool down quite a bit before the second spraying or you'll probably end up with a bit of a bonfire!

Here's a video where the chap used it on a wheel bearing:



Notice how much product he's using. You do need to give it a good skoosh and then repeat several times. One brief squirt, as you would with a releasing fluid, isn't going to get the job done. I think it does the freezing as the fluid evaporates? It adds to the cost and I don't use it often - only bought one can so far - but it does seem to work very well. The next job I can see me using it on is going to be when I replace Becky's rear axle when I can see me using it on the 4 stud nuts which hold the hubs to the axle flanges.

 

[ReadySteady98]

No no luck still. How easy is it to replace a front manifold by yourself?

Anyone know?

I have found this website that sells them knew and comes with a 2 year warranty?

Is it an easy job?

Also would it come with o2 sensor on it preinstalled?


Thanks

 

[koalar]

No no luck still

Maybe someone can help you
I am near Crewe

It should still come out

Worse case someone has to weld a nut on top

. How easy is it to replace a front manifold by yourself?

You will have a worse job getting the bolts out of the front heat shield if still fitted

The should be 10mm but they will be rusted solid and the heads will have corroded to about 9mm now

You stand about a 20% chance one of the exhaust studs will snap. Normally number one cylinder and that’s a bigger job

Anyone know?

Not the way I would go

I have found this website that sells them knew and comes with a 2 year warranty?

Is it an easy job?

On paper yes. In reality it’s unlikely to go well

Also would it come with o2 sensor on it preinstalled?

No

Thanks

 

[Goudrons]

In theory it's easy.
In reality, as Koalar writes, it's a minefield of snapped bolt and studs that will get stuck in the cylinder head.

If you're experienced, you'll take one look at the flange fixings and know you won't get away with swinging on them with a socket set.
They'll be rammed up tight as they aren't ment to rattle loose and they'll be rusty as a 1970's Skoda!
There's also likely to be even more corrosion due to the use of two different metals used in the stud and head.

If you think you've struggled to shift a O2 sensor, what are you going to do when a rusty flange stud snaps in the head?

Instead of paying £160 for a new manifold plus more for a new gasket and then 2 new O2's plus still have the hassle of removing and fitting it, why not drop a large drink into the pocket of your local garage to sort the stuck O2 out.

Even if you've mullered the nut on the one in there, they should be able to heat the manifold up locally so it turns cherry red and use some grips or a stilson on it to remove the old one.

 

[A3jeroen]

Uhm...

M6 =10mm spanner
M8 = 13
M10 = 17
M12 = 19

 

[Pugglt Auld Jock]

In theory it's easy.
In reality, as Koalar writes, it's a minefield of snapped bolt and studs that will get stuck in the cylinder head.

If you're experienced, you'll take one look at the flange fixings and know you won't get away with swinging on them with a socket set.
They'll be rammed up tight as they aren't ment to rattle loose and they'll be rusty as a 1970's Skoda!
There's also likely to be even more corrosion due to the use of two different metals used in the stud and head.

If you think you've struggled to shift a O2 sensor, what are you going to do when a rusty flange stud snaps in the head?

Instead of paying £160 for a new manifold plus more for a new gasket and then 2 new O2's plus still have the hassle of removing and fitting it, why not drop a large drink into the pocket of your local garage to sort the stuck O2 out.

Even if you've mullered the nut on the one in there, they should be able to heat the manifold up locally so it turns cherry red and use some grips or a stilson on it to remove the old one.

Definitely the way to go. Seized O2 sensors are very common and a problem dealt with on a regular basis by any garage. You've given it a valiant go Ready Steady, cut your losses and give it to a garage (preferably one you trust or one somebody else has recommended) to sort out before you turn it into more of a problem.

 

[Goudrons]

Yes, I made a slip with the spanner size, but the point made it correct.
The bolt shaft might double in diameter but the torque it can be put under doesn't just double but can increase by a factor of 10.

So if you are trying to shift a big nut or bolt, use a tool that fits the nut/bolt properly not just some or most of it, otherwise you more than likely end up with like the OP.

If they had gone in and used a decent six sided socket first, it would be out by now.

 

[koalar]

If you're experienced, you'll take one look at the flange fixings and know you won't get away with swinging on them with a socket set.
They'll be rammed up tight as they aren't ment to rattle loose and they'll be rusty as a 1970's Skoda!
There's also likely to be even more corrosion due to the use of two different metals used in the stud and head.

Correct I have had three pandas of this age the heat shield bolts have always been a pain. I think the last one I did 3 out of 4 snapped. I did eventually get all the broken bits out using mole grips and torch

If you think you've struggled to shift a O2 sensor, what are you going to do when a rusty flange stud snaps in the head?

Correct. Plus if you need exactly the right extension bars as access is very restrictive.

Instead of paying £160 for a new manifold plus more for a new gasket and then 2 new O2's plus still have the hassle of removing and fitting it, why not drop a large drink into the pocket of your local garage to sort the stuck O2 out.

Correct

Even if you've mullered the nut on the one in there, they should be able to heat the manifold up locally so it turns cherry red and use some grips or a stilson on it to remove the old one.

Correct. Probably better it’s rounded than pulling so hard that the threads pull out or the top twists off.

 

[rmjbn1]

We've all been there with a stubborn bolt that just won't shift. A combination of heat/impact/force is usually the only answer to break the bond when something has fused together.

Getting a bolt red hot, then a socket on it and whacking it with a hammer to shock it free has worked for me.

A mechanic with an impact gun would probably make it look laughably easy.

Having the right tool for the job isn't to be underestimated. I had to give up on a diff drain plug once, took it to a garage then watched in dismay as they simply put a 3/8 driver into the square recess I struggled on so many jobs with my own small driver, improvising extensions for more leverage until I bent the handle completely out of shape. I wouldn't be without my 600mm breaker bar now - it applies torque so much more efficiently than any driver could.

 

[koalar]

Yes, I made a slip with the spanner size, but the point made it correct.
The bolt shaft might double in diameter but the torque it can be put under doesn't just double but can increase by a factor of 10.

So if you are trying to shift a big nut or bolt, use a tool that fits the nut/bolt properly not just some or most of it, otherwise you more than likely end up with like the OP.

If they had gone in and used a decent six sided socket first, it would be out by now.

It’s not a bolt

It’s a threaded hollow tube with a sensor running through the middle

You have to break the bond between the CAT and the sensor first.

Otherwise just pulling as hard as you can will either damage the head, twist the top off or pull the threads out

I have never seen one of this age that would come out safely without heat

 

[Yolanda]

There's a couple of ways of going about this as a lot of people on here I'm sure are aware of, but I don't think has been mentioned.
1 You can apply heat to the bolt/sensor/pin which ever it is, leave for say 5 mins to cool off which can break the seal that's causing the problem.
2 Heat the surrounding area rather than the bolt/sensor/pin which will expand the metal then immediately try to undo the offending part.
I must add here that to date I've never had to remove a sensor as in the topic, but that's what I would try.

 

[jrkitching]

Thinking outside the box, concentrated hydrochloric acid will preferentially dissolve rust on corroded steel - it's widely used in industry to 'pickle' steel to get a clean surface prior to further treatment. I've used it to good effect to derust small parts, and if you could somehow dribble it between the threads, it just might make the difference. I've occasionally found it helpful in dealing with rusted connections that can't be freed by any other means.

There are a number of cautions; it's a hazardous chemical, so you must absolutely use eye protection and acid-resistant gloves; in any industrial setting, there'd be a full eyewash station close by. You need to be aware of the risks and use it sensibly. In concentrated form, it fumes, and the fumes are extremely toxic; take great care not to inhale any. If it gets where it's not wanted, wash it off with copious amounts of water. When using this, I always keep a garden hose with a spray gun attached, turned on and close to hand.

Also you absolutely don't want any getting inside the cat, so the emphasis is definitely on putting a small quantity around the threaded portion of the sensor, not splashing it over the manifold with a bucket!

It's surprisingly available; here, for example; and I've seen the same product in a number of independent hardware shops. For rust removal on steel, I find diluting it 1:1 with water works well - this will give about an 18% HCL solution.

Since the existing sensor will be scrap, another option is to use a dremel to cut it off, and then work carefully to remove enough of the centre portion to break the bond that the corrosion is causing. Again, be careful not to drop anything into the cat; if you have to take the manifold off to get something out, you'll have to deal with all the problems @koalar has previously mentioned.

The big advantage you have is that your time is free, and you can afford to spend a hour or two if need be; something that wouldn't be economic for a trader.

 

[ReadySteady98]

Maybe someone can help you
I am near Crewe

It should still come out

Worse case someone has to weld a nut on top

You will have a worse job getting the bolts out of the front heat shield if still fitted

The should be 10mm but they will be rusted solid and the heads will have corroded to about 9mm now

You stand about a 20% chance one of the exhaust studs will snap. Normally number one cylinder and that’s a bigger job



Not the way I would go

On paper yes. In reality it’s unlikely to go well

No

Where is crew again sorry?

I have had a new exhaust fitted about 2 weeks ago so they are in not bad shape if I had to remove it to replace the manifold.

Here are some pics

 

[koalar]

Cheshire north of Birmingham south if Manchester

 

[ReadySteady98]

Cheshire north of Birmingham south if Manchester

If I was closer I would have definitely took it to you. I’ll tell you what even tho I have an engine light that won’t clear because of the o2 sensors for a 15 year old car it still drives fantastic, didn’t expect much of it when I bought it for £500 at the time.

 

[jrkitching]

Another issue I can see from your second photo is that both the lower cat support bracket and its securing bracket on the bellhousing are missing.

These are needed to support the bottom of the cat and hold it securely to the engine; without them, any movement in the exhaust puts stress on the cat, which can lead to the manifold cracking.

You can see a telltale circle on the bellhousing showing where this second bracket used to be attached.

I'd strongly advise you to get these brackets replaced, or you could end up needing a new manicat.

The bracket on the bellhousing is pretty durable, but the one on the bottom of the manicat often rusts away. Here's one I replaced last year.

AFAIK they're dealer only parts, which may explain (but not excuse) why your exhaust has been fitted without them. I'm guessing whoever fitted it removed and discarded the part attached to the bellhousing to make its omission less obvious.

 

[koalar]

Looks like it’s had some been maintained not much leaking and looks like a new brake pipe

as per @jrkitching the bracket is missing or taken off

 

[koalar]

what tyres

Looks like road legal slicks

 

[koalar]

I can’t visualise this bit at the back