1996 850 GLT Need to find vacuum leak >> found

osmium · Post by **osmium** » 20 Feb 2014, 14:01

My 96 850 GLT has given em its first check engine engine light in the 4.5 years I've owned it. (Started at 168k, now at 221k)

The code is a P0172. So i'll be looking for a vacuum leak.

I'll try the cigar method.

My question is can I just attach a hose to one the the extra connection on the vacuum tree? or is there better location.

I checked the vacuum connection on the left side of the manifold. It seemed ok.

-os

Post by **misha** » 20 Feb 2014, 14:35

P0172 is usually an elbow at the left side of the manifold(vacuum line),but can also be:
-fuel pressure regulator (vacuum side of the line)
-fuel injector's o ring(s)

...rarely but happens.

FCPEURO · Post by **FCPEURO** » 20 Feb 2014, 18:16

Probably the elbow. That joint break very easily and is very common to breakage.

osmium · Post by **osmium** » 20 Feb 2014, 21:17

I took a look at the elbow from the left side of the engine and could see a crack where the elbow fits into the manifold. The other end of the elbow is connected to a larger piece of tubing.

Is this the correct replacement?

http://www.fcpeuro.com/products/volvo-v ... -9155862oe

or

http://www.fcpeuro.com/products/volvo-v ... ng-1389574

-os

Post by **erikv11** » 21 Feb 2014, 00:20

If the elbow is cracked then the PCV tubing may be deteriorating in general. The car may need a PCV servicing and a quick look at all of the vacuum lines.

I think it is the large-small elbow but I wouldn't buy it. Your best bet is to just walk into any auto parts store and get 3 or 4 feet of rubber, 5/16 vacuum line. It will be cheap. Run a fresh piece of line from that nipple in your photo over to where the existing hose connects to the flame trap housing, next to the throttle body. Choose any route you like, under the manifold or around the front. The vac line will last longer, be easier to install, and work better than the thin, hard plastic tubing that is in there now. Just leave the old hose in there.

osmium · Post by **osmium** » 21 Feb 2014, 07:51

Thanks, I was thinking of doing that see as it was probably going to be a PITA to get the elbow into the larger tubing. But I was going to look for the other connection on the vacuum tree.

The other connection is located by down by the flame trap, or is the vacuum tree considered part of the flame trap housing?

-os

Post by **misha** » 21 Feb 2014, 10:11

osmium wrote:...is the vacuum tree considered part of the flame trap housing?...

No, it's independent part.

osmium · Post by **osmium** » 21 Feb 2014, 10:29

misha wrote:
osmium wrote:...is the vacuum tree considered part of the flame trap housing?...
No, it's independent part.

So, If i am going to reroute the vacuum line, one end goes from the connection on the left side of the manifold; the other to a connection near the flame trap.

-os

Post by **misha** » 21 Feb 2014, 10:30

The other end goes to the nipple on the flame trap.

osmium · Post by **osmium** » 21 Feb 2014, 10:41

misha wrote:The other end goes to the nipple on the flame trap.

Great, thanks!

I would have wasted a lot of time trying to figure which connection it was on the tree.

Probably toss the flame trap while I'm done there.

-os