2001 V70XC - 200,000 Miles Makeover Topic is solved

[xHeart]

The undercarriage tapping is loudest where the bracket holds the catalytic converter.

I looked closely the way bracket is holding the catalytic converter. It consists of items 8-12 in the diagram below:


If bracket is undone the cat will be suspended from turbo at item 2 and exhaust with item 22. It is likely, without bracket support, I would imagine, this would cause the flex pipe to fail? This bracket assembly:


Unless you say other, using bottle-jack may be best to support the cat while the bracket is removed to look for what causes tapping? Anyone with tapping experience -- is it a warning audio for failing O2 sensor located right above?

[- Pete -]

Your 01 may be different, but taking that bracket down to inspect won't hurt a thing. There are a few (3, I think) plastic retainers that secure rigid brake/PS lines and one that retains the wire for your rear O2 sensor. Just squeeze those with a needle-nose to allow the metal plate to drop down. Remove the 4 12mm bolts & the plate should just drop down. There are separate "hangers" (#4) helping to hold up your downpipe/catalytic converter above this plate, so no worries about the flex joint.

I can't see the part number on your image, but it doesn't look like the turbo 2.4/2.5T downpipes I'm used to seeing. It looks more like the NA DP like Biggertuna posted about recently, but I could be wrong. Either way, removing the plate won't hurt a thing. Also, don't order a new plate. There's likely nothing wrong with the old one, but something in that vicinity is making the clatter.

Edit, I found this, shows fitment for turbo'd models. I've never seen this part before though. If yours has it maybe it's broken & making the noise as your exhaust vibrates.

https://parts.volvocars.ca/p/Volvo__S60 ... 80834.html

[xHeart]

Your 01 may be different, but taking that bracket down to inspect won't hurt a thing. There are a few (3, I think) plastic retainers that secure rigid brake/PS lines and one that retains the wire for your rear O2 sensor. Just squeeze those with a needle-nose to allow the metal plate to drop down. Remove the 4 12mm bolts & the plate should just drop down. There are separate "hangers" (#4) helping to hold up your downpipe/catalytic converter above this plate, so no worries about the flex joint.

I am suspecting the rigid brake line knocking on bracket. One plastic retainer was out.
Here is progress pix:

MVS_CatHanger_0945.jpg (160.05 KiB) Viewed 1383 times

MVS_CatBracket_0947.jpg (122.89 KiB) Viewed 1383 times

[abscate]

Nice pictures xheart, worth 2x10E3 words.

[xHeart]

Nice pictures xheart, worth 2x10E3 words.

I appreciate that you appreciate skipper.

IF, it is the hard brake line coming loose from the retainer, THEN, it is likely from the caliper and brake line flaring I did around November 2019. This routed brake line goes to the passenger side caliper.

FWIW, this thread viewtopic.php?f=9&t=91484

[xHeart]

Cleaned off rust on the hanger and gave it a hight temp rust prevention coating. The two retainers are good, no crack or tounge damage. Inserting 2 rubber rollers as spacers around the hard brake line.

MVS_CatHanger_0946.jpg (162.4 KiB) Viewed 1362 times

MVS_CatHanger_0951.jpg (131.27 KiB) Viewed 1362 times

[abscate]

That must get nasty working on those driveshafts sitting near that hot exhaust,getting road salted all the time

“ invokes the FWD prayer of thanks”

[xHeart]

That must get nasty working on those driveshafts sitting near that hot exhaust,getting road salted all the time

“ invokes the FWD prayer of thanks”

Indeed, I see the simplicity of our FWD 1997 850.

Keeping AWD would be a commitment of time and money. Not a joyful feeling to see another multi-step repair coming.

[xHeart]

The cat support bracket is restored and back on. Car starts like a charm, and took it for a lone drive. The occasional tapping sound is still present. It appears randomly with no particular interval, moment, or tied to a rpm.

Going back to diagnostic desk.

[- Pete -]

Does it coincide with small surface imperfections in the road?

I’ve been thinking about this for a while now. I’m wondering if your original sway bar bushings are worn to the point that you’re hearing the bar making percussion noise?

The front sway bar is right there in that vicinity & is an a annoying & slight sound. The bar on my 04 XC70 285k miles rattles a bit. My 04V70 AWD is beginning to emit a similar sound.