Help with missing tube on '98 V70

dynamaniac · Post by **dynamaniac** » 08 Sep 2018, 11:13

My trusted mechanic has helped me with some significant work on my '98 V70 NA over the last two years, so I wasn't happy to run into some snags getting the car smogged this morning. The first snag was a STAR smog testing facility that claimed they couldn't run the test, and that I needed to take my car to a "smog referee," the nearest of which is located at a community college in Alameda (I live in Oakland, CA). Strange...

After doing some digging I decided to get a second opinion from a different smog tester. This smog tester looked at the car's records and told me it was unlikely my car actually needed to go to a referee... but then he noticed that a tube was missing, connecting the back of the engine to (what looks like) the intake snorkel? So he recommended I replace the part before having him run the test (automatic failure from visual inspection due to missing tube at this point).

Here are two pictures of what I'm supposed to connect with some cheap, silver accordion tubing:

(Back of engine - for some reason this image is rotated weirdly)

(looking towards the front of the car on the driver's side)

Any ideas why my mechanic wouldn't have flagged this previously? I had him replace my rear main seal (

) a few months ago, and he was happy to replace a hydraulic engine mount in the long process of that repair.

Any tips on what type of tubing I should buy and how I should install it? I'm struggling to ID these parts and could use some pointers. I also wonder if this tube is unnecessary... but can't find documentation confirming or disproving this thought. Thanks as always, this community is a lifesaver for a novice Volvo enthusiast like myself.

dynamaniac · Post by **dynamaniac** » 08 Sep 2018, 12:33

Update: took me longer than I'd like to admit, but I now believe this is the "hot air intake" hose, connecting the exhaust manifold with the airbox. Also found a comment online that it's fine to get rid of this tube, EXCEPT that in California, it's part of the emissions system so it would force a fail on a smog test. Ugh. So to update my query: should I replace this hose just for the smog test, and then remove it? Do I need to test that the spring-loaded flap in the airbox works to ensure that hot air is not routed to the intake once the engine is warm? Any other tips for managing this aspect of my V70?

Post by **abscate** » 08 Sep 2018, 13:58

Replace it and leave it. Your Car will be happier with temp control on the inlet air

dynamaniac · Post by **dynamaniac** » 10 Sep 2018, 13:39

Thanks, abscate!

Post by **erikv11** » 10 Sep 2018, 14:38

In Oakland CA: replace it and then pull it back off after inspection. You can get one at any auto parts store, just generic flex tubing like that in the exhaust parts section. It feels/looks like a metal-lined cardboard, about $12.

Your car will be happier with cooler air most of the time, than with the hot air that comes from the around the exhaust manifold, especially if the thermostat in the air box has failed. You can even block off the air box side if you want, then all intake air is from the front snorkel.

Sorry to see that SAS valve in the top pic - you probably also have to keep the air pump running and present, to pass CA smog.

dynamaniac · Post by **dynamaniac** » 10 Sep 2018, 15:18

Gotcha, thanks erikv11. I'm now reading about SAS... I wouldn't have a good reason to look into "delete SAS" given that I'll be subjected to emissions testing every two years here in CA? (I've read through a few forums postings on this, but I'm not 100% on the pros/cons/contingencies of bypassing the SAS when smog tests are a given)

Post by **Clemens** » 11 Sep 2018, 00:31

You could move to Calaveras county. They don't smog out there ...
It's not even that bad of a commute

Post by **erikv11** » 11 Sep 2018, 00:37

The deal with SAS and CA cars is that if the tech knows what they are doing somewhat, and do their job of looking for the emissions sticker and checking if the equipment is all there, then you will fail by completing the SAS delete. The air pump won't be hooked up, vacuum tubing removed. It used to be a problem for CA P80 Volvos. Now that the cars are getting older I don't know if people are getting away with it these days or not, but it probably depends on where you go for the smog check etc.

I highly recommend SAS delete whenever it won't cause inspections pain. If you want to take the approach of leaving the hardware in place and hooking it back up at inspection time, that might work. By not running the air pump and removing the SAS-pump connection in the intervening time, you should reduce the frequency of pump failure and save some $ and hassle in the long run.

Post by **abscate** » 11 Sep 2018, 03:03

Isn’t there also a fix of putting a drain hole in the pump to remove water?

Post by **erikv11** » 11 Sep 2018, 08:59

True! Preventive step.