Removed flametrap, broke a hose

iguanoid · Post by **iguanoid** » 05 Nov 2012, 16:20

Hello forum! First post here (though I've been lurking for a couple weeks)

I recently bought a 1997 850 (sedan, base model). After reading around on this forum I decided to remove the flame trap. When I loosened the crankcase ventilation pipe (I think?) the smaller hose attached broke...well, crumbled actually. It seemed that the hose was completed clogged.

I removed the flame trap and put everything back together (minus the broken hose of course) and started the engine and it sounded the same more or less.

My guess is that this hose was...well, hosed, before I did anything. And that I am not running any worse than I was before...but...I don't really know.

But my question is....will I be okay to drive to work like this before I can order a replacement crankcase ventilation pipe?

Thanks!

iguanoid · Post by **iguanoid** » 05 Nov 2012, 16:25

Ahh, I tried to attach an image...let me try again....

Post by **erikv11** » 05 Nov 2012, 17:15

EDIT: Welcome to MVS!!!

Yeah, the hose is probably clogged and that is what is keeping the car from reacting to the vacuum leak that might be created by breaking the hose. It will be OK to drive it. Be sure you get OEM on that part, the aftermarket ones don't last very long. In truth it sounds like your car is due for the basic PCV job, I'd do it all.

iguanoid · Post by **iguanoid** » 05 Nov 2012, 17:21

Thanks Eric,

I will definitely do the entire PCV kit asap. But before I will be able to buy that I will replace just these hoses. Do you know if they are difficult to replace?

I am a little confused...how can there be a vac line on something that opens to the air intake?

Post by **erikv11** » 05 Nov 2012, 17:30

The other end of that small hose connects over to a nipple on the intake manifold, tucked in behind the power steering pump. So there is a small vacuum draw through it. It is the small one that broke. not the large one?

You can replace the small hose by just running a hose from the flame trap housing over to the nipple, take any route you please. There was a post from matthew1 a while ago that showed a fat hose routed around the front, worked great. So any hose will do, use fuel line of vacuum hose whatever.

Post by **xHeart** » 05 Nov 2012, 17:37

To help it along Volvo p/n 9146757 - $31.67

I recently replace PCV on my 1997 850 NA.
You may find this post helpful...

iguanoid · Post by **iguanoid** » 06 Nov 2012, 08:24

Thanks everyone. I am much clearer on what is going on now.

To clarify, yes, it is the smaller line that broke.

I am still confused about the vacuum line though....by my reasoning this vacuum line is open to the air intake. How is this any different than a vacuum leak? What is the vacuum line there for?

Post by **jblackburn** » 06 Nov 2012, 08:33

The vacuum line just goes back to the intake. It is there to alleviate oil vapors near the throttle body from the PCV system at idle (when the oil separator can't really filter anything because it doesn't have enough suction) and nothing more. Like the standard PCV valve in your average car.

Volvo's system is a little better than just sucking the vapors back into the intake at any engine speed, though. It separates them out when running down the road and dumps the oil droplets back into the oil pan. Keeps your valves, emissions, etc. cleaner.

An open end at one end of the small vacuum hose will create a vacuum leak of unmetered air.