1999 S70 Vacuum line on passenger side

volvooh · Post by **volvooh** » 28 Aug 2013, 14:00

I found yet another vacuum line unattached. This near the P/S pump on the passenger side. One end goes into the intake, but when I pulled the vacuum line, the whole thing came out. I have no idea where the other end goes. I think if I can get this fixed it will solve my low RPM problem. The elbow that attaches the tube to the intake appears to have rotted- I ordered another to replace it....now I think I may need 2???

Post by **mikealder** » 28 Aug 2013, 14:12

That hose is part of the PCV system, it connects to the air pipe that returns crankcase pressure to the inlet manifold - Mike

dir3kt0r · Post by **dir3kt0r** » 28 Aug 2013, 14:16

When you say intake, do you mean intake manifold?
if you do, then I'm assuming it's the vacuum elbow that goes in right to the side of the manifold? That one is a part of your PCV system which needs to be serviced I think around 100 K. I just did mine not too long ago, there's a great how to walkthrough on the site. I think it cost a little bit over a hundred dollars in parts and took anywhere from 5 to 6 hours of my time to put it in.

Do you have a smoking dipstick? The check you pull the dipstick out while the car is running, with the engine is in normal operating temperature. And see if you see any smoke coming out.

volvooh · Post by **volvooh** » 28 Aug 2013, 14:43

It is the vacuum elbow. It appears I have yet another project!!!

In the mean time, where is the air pipe leading to the crankcase located. I would like to get this re-attached and then get parts ordered in the mean time. It appeared to come out from behind the intake...is that going to have to be removed in order to re-attach this line?

Post by **erikv11** » 28 Aug 2013, 15:03

Is this S70 a turbo or non-turbo?

volvooh · Post by **volvooh** » 28 Aug 2013, 16:13

non-turbo

dir3kt0r · Post by **dir3kt0r** » 28 Aug 2013, 21:40

im not sure about non turbo 70 series but on mine that line went behind the intake manifold, and looped around the engine block and connected to the air pipe near the turbo. so i would suggest that u look for the rest of that line somewhere in that area along the air pipe... once again tho im just taking a guess here about a non turbo location....

Post by **erikv11** » 29 Aug 2013, 01:26

On a non-turbo that thin PCV vacuum line connects from the metal nipple on the intake manifold (IM) to a plastic nipple on the flame trap housing, tucked just below and in front of the distributor cap. The non-turbo's flame trap housing connects to the engine air intake post-MAF, similar in concept to where the PTC sits on a turbo model, so the two setups are analagous.

The flame trap housing may well be an oily mess, good opportunity to clean it up a little. You can just connect standard vacuum line (3/16 ID works well) from nipple to nipple, I always leave the old, broken hose in place until I make time to pull the IM and do a full PCV service. With long, long nose pliers you can easily attach the vacuum hose at the IM side.

volvooh · Post by **volvooh** » 29 Aug 2013, 08:07

Thanks for the replies- I went and took a quick look- there is no distributor cap on this engine- each spark plug has its own coil. As a clue, the line I pulled out was very thin and about 8 inches long. At one time it had a elbow coming off the intake manifold. Am I to presume this line vents gasses back into the manifold???

Post by **erikv11** » 29 Aug 2013, 08:23

Oops, your car is a 99 not a 98, sorry about that ...

The PCV routing is still as I described. The reason the line was so short is because it broke, you are going to need a couple feet to replace it, or more if you want to route it other than under the intake manifold. You are basically replacing the smaller diameter line of this combo hose:

There is no distributor cap but the connection you are looking for is where the cap would be: no the rear end of the intake cam. Pull out the airbox because it is easy to do and gives you lots of room, then as you are on the driver's side looking at the engine it will be sort of on your lower left.

The reason to now do a full PCV service is because the larger diameter line (crankcase breather pipe that mikealder mentioned) is likely also falling apart, and the orifices where the system connects to the block may be clogged up. The larger diameter hose you can replace with heater hose, there are writeups on this site for both jobs.