Rusty muffler flange - How to detach it

[Metallo]

Hi guys,

My car is an XC 70 AWD 2006.
I am working to replace my muffler, rear and central part, so far I cut the old muffler into multiple parts and removed it.

However, I am now stuck to remove the flange as it is a block of rust.
I tried to cut it and to drill it, but it is very difficult to drill when the catalytic converter is in place and it is moving.

Please see the pictures below to have an idea:







Ideally, removing the catalytic converter would facilitate to drill the flange, but I am not sure how to remove the converter and how long it takes.

Also, any idea which screws should I use to fix the whole thing again?
Wouldn't stainless still screws be a better option?

Thank you!
Alex

[oragex]

Try flatten with a grinder the side with the nut, then press/drill the sucker out (careful not to ruin the flexible or the core of the catalytic converter). On the other side the stud is slightly pressed in, looks like this http://europartshouse.com/images/Volvo- ... ar-700.jpg
The four bolts at the flexible/manifold may be easier to undo, given the socket fits properly over the rusted nuts. Besides, the flexible will start leaking in not long.

[Metallo]

Hi there,

I tried to drill already, but believe it or not, nothing is moving,
I tried with the heat gun, nothing.

On the other hand, if I look at Vida, the P/N for those screws is: 982797, they seem to be regular bolts to me, but who knows.

At this point, I think I will have to remove the converter.
Here is what Vida says:

Catalytic Converter.pdf

(229.01 KiB) Downloaded 403 times

In the Pdf, they say to remove the 'front SIPS member'. I have no idea what it is, I only know the meaning as being the Side Impact Protection System.

When you say the flexible will start leaking in no long, do you mean I will have soon to change the whole catalytic converter?
I'd better prepare myself as it is very expensive

Thanks
Alex

[oragex]

The catalytic converter lasts forever on this car. The flexible downpipe just in front of the cat starts leaking after about 8-10 years and will need replaced - cut & weld. It is not expensive, I'd put an interlock type which is durable (see this one how it looks deep inside http://www.ebay.com/itm/301565779899?_t ... EBIDX%3AIT)

The sips may be the metal plate with 4 bolts that supports the cat bracket.

Just need to measure properly the length and the inner diameter of the original flexible pipe. The mechanic should know how place the new flex pipe in the exact position prior to welding.

I'd also check the flange at this place, it often times wear and leak. Some surface weld and surfacing with a grinder can help this.

Good time for a new front O2 sensor if it's original as well.

[Metallo]

Hi,

Thank you for your advice, I really appreciate it.

I am a bit discouraged, this is my first time replacing the muffler on this car and I did not expect to be so much trouble, that flange is driving me crazy.

I have some more questions for you before I begin to disassemble the converter:

Please look at the picture below:



Is #2 the front oxygen sensor? If so, how do I remove it? Do I have to undo the bolt?
#1 is not visible due to the shadow, but there is the third bolt, very difficult to reach, I may be able to undo it, but I am concerned to put it back, any hints?

Now the connector below, I cannot disconnect it, do I have to press both plastic flaps or expand them?



Finally, the two shackles, do I have to remove only the upper part I circled?



Thank you!
Alex

[oragex]

Not in order, all electrical connectors on Volvo are a mystery and build to survive a nuclear attack. Look closer to it, there should be a tab to depress on either side - use a flat screw driver to force the tab down while pulling to disconnect it, fingers simply are not strong enough.

I don't own a turbo but usually the sensor in front of the catalytic converter is the main O2 one. There is a special open flare tool to put on the 6 facet nut and twist it, an adjustable wrench or fixed wrench can do the same given there is space for them - you can try installing a wrench on the nut, then use another tool/bar blocked on some engine part to pry and push on the first wrench. The sensor is not too hard to undo but surely hands are not strong enough on that tight space.

The bolts to the manifold really aren't rusted and should be easy to undo prying the same way as above. Can't help for the hidden one, maybe there are tips already on older forums.

Exhaust really is not a pleasant job, among a few ugly jobs on this car. Last picture, try removing the whole lower plate with the cat on it. The rubbers are very hard to slide off their rod, needs a large pliers and grease over the rod. A helper is very useful when handling the cat converter to remove it from there, not exactly easy to handle. Final and quite important tip, the aluminum heat sheets you see all around will bend and rattle like .. later on. After replacing everything, tap on each sheet to hear if it vibrates.

[Metallo]

There are two sensors according to the Pdf above, front and rear, so tomorrow morning I will try the adjustable wrench or flared one.

The bolts on the manifold should be easy, I agree, but the third one will be a mess due to its position.

The heat sheet is fixed using plastic pins, I will have to break them and then find new ones to replace the old.

The connector is a mystery to me, I press both tabs on the right part, (they are visible in the picture), but it does not disconnect.

Tomorrow morning I will be back and hope I can remove the whole thing, also because I have no alternative in order to remove that flange between the converter and the exhaust.

Thank you very much for your help, I will let you know how things evolve.

Alex

[oragex]

The first sensor after the engine is usually the main one. Good luck and resilience

[Metallo]

Hi,

I have decided to give up to remove the converter, there is no way I can unbolt the third bolt on top and even the other two would be a mission, there is no space to use the conventional wrenches or sockets I normally use.
I will bring the car to a shop to see if they can detach the flange without removing the converter.

Thanks for your advice!

Alex

[Metallo]

Hi again,

Believe it or not, I managed to detach the flange

I used the grinder and then drilled again with a bigger drill bit from the opposite side I drilled the first time, it popped out.

Alex