1998 V70xc catalytic converter job

Post by **850 LPT** » 17 Dec 2014, 07:16

The gas mileage on these cars varies very much depending on your driving style and what kind of driving you do.
I manage to get 23.5 mpg on my commute which is 1/3 back roads and 2/3 highway. This is without AWD, with AWD it is 23 mpg.
On the other hand, our brand new 99 XC used to get only 19 mpg average because it was used less on highway but more city and mixed driving.
If you floor it all the time and never take it on the highway your mpg sounds about right.

You have a very nice XC by the way! I like the color combination and the upgrades that you did.

Good luck with the cat install. I will follow this closely because I can see myself having to deal with this at some point.

Dirk

pedal2metal · Post by **pedal2metal** » 17 Dec 2014, 21:13

Thanks Dirk; I liked the colors too, but regret that I bought it in a spur of the moment type deal. I paid 4k for it (148k miles at the time w/ new timing belt/h2O pump & new battery). Of course after I bought it several 99-00 XCs came up for sale near me for 2k range w/ less miles. Oh well, live & learn. Well I started the cat job tonight & it is already a pain in the butt. I'll take pics and document everything as I go along.

Post by **deepsouth** » 18 Dec 2014, 12:14

I did this on my 1998 AWD V70 and it was an absolute PITA. I couldn't get it around the bevel gear and ended up using a cutting tool. Of course, I didn't put in a replacement cat, rather rigged up a straight pipe with a resonator and a welded in O2 bung.

https://www.matthewsvolvosite.com/forums ... =1&t=59607

pedal2metal · Post by **pedal2metal** » 18 Dec 2014, 17:31

You are not kidding! I spent all day on yanking the old downpipe/cat unit out... all day! What a pain in the backside (& my neck). I think this new unit will snake around the bevel gear box, it appears. God, I hope so.... I'm documaenting this nightmare. I took the old leaking turbo out to put a 16t in & that helped to make some room.

pedal2metal · Post by **pedal2metal** » 19 Dec 2014, 17:34

Ok, I got the new downpipe in... I had to remove the bevel gear case. (fun) Now I might dump the oil out of that and put in some fresh. I think I read 75/90wt that most people use?

Post by **Ozark Lee** » 19 Dec 2014, 17:53

I use 75W90 GL-5 which is synthetic. I think I used Royal Purple since I had some laying around.

There may be a drain on gear if it has been modified. The modification was to remove the bottom stud and drill a hole though it that is slightly smaller than the stud itself. The stud then gets wrapped with teflon tape and re-installed to seal the newly drilled hole. I drilled mine out while the transfer case was out since it was easier to get the drill lined up and not mess up the threads.

...Lee

Post by **E Showell** » 19 Dec 2014, 18:18

Don't forget to take the dead cat (you see what I did there . . . ) to the local scrapyard. There's a fair bit of precious metal in there. Got $70 for mine when I scrapped it.

pedal2metal · Post by **pedal2metal** » 19 Dec 2014, 18:25

Ozark Lee wrote:I use 75W90 GL-5 which is synthetic. I think I used Royal Purple since I had some laying around.

There may be a drain on gear if it has been modified. The modification was to remove the bottom stud and drill a hole though it that is slightly smaller than the stud itself. The stud then gets wrapped with teflon tape and re-installed to seal the newly drilled hole. I drilled mine out while the transfer case was out since it was easier to get the drill lined up and not mess up the threads.

...Lee

Thank you! There is the fill hole, so I was just going to tip the case over & drain it from there since it's out laying on the garage floor. I highly doubt I'd ever do it again. I am hoping it'll last a couple more years; no car payments is nice. This car most likely does not have tapped hole; I'll have to look though. (I think it was your post I found one time talking about that) Is that aluminum box a dampener? The people who owned it before me, did ZERO to this poor car to keep it maintained. It saddens me the more crap I find with it...

pedal2metal · Post by **pedal2metal** » 19 Dec 2014, 18:26

E Showell wrote:Don't forget to take the dead cat (you see what I did there . . . ) to the local scrapyard. There's a fair bit of precious metal in there. Got $70 for mine when I scrapped it.

Oh, I'm all about the scrapping! lol. I have box of well pump wire, a bucket of brass, some copper & a few old car batts. to go as well; Thank you for reminding me!! -Royce

Post by **850 LPT** » 19 Dec 2014, 19:13

Is that aluminum box a dampener?

I believe it's called a counter balance weight, but I'm not totally sure. Just some extra weight to drag your mpg's down

BTW, how are the seals on that bevel gear? Now's the time to change them if it's leaking.

I did that on mine, but a few thousand miles later it fell apart anyways.

Glad you got that cat in.